ansi guideline for injection molding

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for Plastics Machinery –Horizontal Injection Molding Machines –Safety Requirementsfor Manufacture, Care, and Use

ANSI/SPI B151.1-2007A

NSI

/SP

I B

151.

1-20

07

ANSI/SPI B151.1-2007(Revision of

ANSI/SPI B151.1-1997)

American National Standardfor Plastics Machinery –

Horizontal Injection Molding Machines –Safety Requirements for

Manufacture, Care, and Use

Sponsor

The Society of the Plastics Industry, Inc.

Approved February 6, 2007

American National Standards Institute, Inc.

Approval of an American National Standard requires review by ANSI that therequirements for due process, consensus, and other criteria for approval havebeen met by the standards developer.

Consensus is established when, in the judgement of the ANSI Board ofStandards Review, substantial agreement has been reached by directly andmaterially affected interests. Substantial agreement means much more thana simple majority, but not necessarily unanimity. Consensus requires that allviews and objections be considered, and that a concerted effort be madetowards their resolution.

The use of American National Standards is completely voluntary; theirexistence does not in any respect preclude anyone, whether he has approvedthe standards or not, from manufacturing, marketing, purchasing, or usingproducts, processes, or procedures not conforming to the standards.

The American National Standards Institute does not develop standards andwill in no circumstances give an interpretation of any American NationalStandard. Moreover, no person shall have the right or authority to issue aninterpretation of an American National Standard in the name of the AmericanNational Standards Institute. Requests for interpretations should beaddressed to the secretariat or sponsor whose name appears on the titlepage of this standard.

CAUTION NOTICE: This American National Standard may be revised orwithdrawn at any time. The procedures of the American National StandardsInstitute require that action be taken periodically to reaffirm, revise, orwithdraw this standard. Purchasers of American National Standards mayreceive current information on all standards by calling or writing the AmericanNational Standards Institute.

American National Standard

Published by

American National Standards Institute, Inc.25 West 43rd Street, New York, NY 10036

Copyright © 2007 by American National Standards Institute, Inc.All rights reserved.

No part of this publication may be reproduced in anyform, in an electronic retrieval system or otherwise,without prior written permission of the publisher.

Printed in the United States of America

i

ContentsPage

Foreword ............................................................................................................. iv

1 Scope, Purpose and Application.......................................................... 1

1.1 Scope................................................................................................... 1

1.2 Purpose................................................................................................ 1

1.3 Application ........................................................................................... 1

2 Referenced American National Standards........................................... 3

3 Definitions ............................................................................................ 3

4 Care -- Responsibility for ................................................................... 11

4.1 Instructions......................................................................................... 11

4.2 Training of Maintenance and/or Setup Personnel.............................. 11

4.3 Inspection and Maintenance .............................................................. 11

5 Manufacture, Remanufacture, Repair, Modification and Rebuild ...... 11

5.1 Responsibility..................................................................................... 11

6 List of Hazards................................................................................... 13

6.1 Specific Machine Areas Where Hazards Exist................................... 13

6.2 Other Hazards.................................................................................... 17

7 Safety Requirements and/or Methods ............................................... 18

7.1 General Guarding .............................................................................. 18

7.2 General Safety Requirements............................................................ 20

7.3 Additional Safety Requirements and/or Methods in Specific Machine Areas............................................................ 24

7.4 Large HIMM ....................................................................................... 36

7.5 HIMM with Additional Injection Units.................................................. 37

7.6 Two Platen HIMM .............................................................................. 39

8 Electric HIMMs................................................................................... 40

8.1 Emergency Stop ................................................................................ 40

8.2 Guard Locking.................................................................................... 40

8.3 Electrically Driven Axis of the Platen Movement................................ 40

8.4 Electrically Driven Axis for the Movement of the Plasticizing and/or Injection Unit ..................................................................... 42

8.5 Electrically Driven Axis for the Rotation of the Plasticizing Screw........................................................................ 42

8.6 Electrically Driven Axis for the Linear Movement of Screw or Plunger ......................................................................... 42

8.7 Electrically Driven Axis for Cores and Ejectors.................................. 42

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Page

8.8 Stopping Performance ....................................................................... 43

8.9 Electrcial or Electromagnetic Disturbance ......................................... 43

9 Existing HIMMs.................................................................................. 51

9.1 Employer Responsibility .................................................................... 51

9.2 Mold Area Guarding........................................................................... 51

9.3 General Guarding (Other than Mold Area Guarding)......................... 54

9.4 Additional Safety Measures for Large HIMMs ................................... 55

9.5 Emergency Stop Button..................................................................... 58

9.6 Window .............................................................................................. 58

9.7 Safety Signs....................................................................................... 58

10 Use .................................................................................................... 59

10.1 Training of Operators, Setup, and Supervisory Personnel ................ 59

10.2 Work Area.......................................................................................... 59

10.3 Set Point ............................................................................................ 59

10.4 Part Discharge Area .......................................................................... 59

10.5 Vent Port ............................................................................................ 59

10.6 Ventilation .......................................................................................... 60

10.7 Ancillary Equipment ........................................................................... 60

10.8 Personal Protective Equipment ......................................................... 60

10.9 Mold Guarding ................................................................................... 60

10.10 Interrupted Cycle ............................................................................... 60

10.11 Automated Mold Change ................................................................... 60

10.12 Nozzle Modification............................................................................ 60

10.13 Hose Inspection ................................................................................. 61

11 Safety Signs....................................................................................... 61

Figures

1 Large Machines with Horizontal Clamping Unit with or without Tiebars................................................................... 6

2 Horizontal Injection Molding Machine (HIMM) with Horizontal Clamping Unit and Horizontal Injection Unit, Shown without Guards for Illustration Clarity ............................... 13

3 Reach Over Protective Structure ....................................................... 18

4 Safety through Opening..................................................................... 19

5 Example of Type I - Purge Guard ...................................................... 27

6 Example of Type II - Other Guard...................................................... 27

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Page

7 Example of Type III - Operator Gate - Direct Operated Second Shutoff Device................................................................. 27

8 Example of Type III - Operator Gate - Electrically Operatred Second Shutoff Device................................................................. 27

9 Parts Discharge Opening ................................................................... 33

10 Area Inside the Guard and Outside the Mold Area ............................ 34

11 Principle of Interlocking Corresponding to Type III, using Motor Control Unit according to Category B....................... 44

12 Principle of Interlocking Corresponding to Type III, using Motor Control Unit according to Category other than B for Safe Standstill ......................................................................... 45

13 Principle of Interlocking Corresponding to Type III, using Motor Control Unit according to Category B for Safe Standstill ......................................................................... 46

14 Principle of Interlocking Corresponding to Type I, using Motor Control Unit according to Category B....................... 47

15 Principle of Interlocking Corresponding to Type I, using Motor Control Unit according to Category other than B for Safe Standstill ......................................................................... 48

16 Principle of Interlocking Corresponding to Type II, using Motor Control Unit according to Category B....................... 49

17 Principle of Interlocking Corresponding to Type II, using Motor Control Unit according to Category other than B for Safe Standstill ......................................................................... 50

Tables

1 Safety Distance, Reach Over Protective Structure ............................ 18

2 Safety Distance, Reach Through Opening......................................... 19

3 Verification of Continuity of the Equipment Grounding (Protective Bonding) Circuit ......................................................... 23

Annexes

A Use of proportional valves for platen movement................................ 62

B SPI Recommended Procedures......................................................... 63

C Standstill, safe standstill, Interlock summary and category of motor control unit for Electrical IMMs ................. 70

iv

Foreword (This foreword is not part of American National Standard ANSI/SPI B151.1-2007.)

This standard is a revision of American National Standard Safety Requirements forthe Manufacture, Care, and Use of Horizontal Injection Molding Machines, ANSI/SPIB151.1-1997. The standard was revised because:

(1) Some paragraphs required modification for clarity and intent.

(2) Additional details on electrical requirements were added.

(3) Additional explanatory material and illustrations were added.

(4) Additional definitions were required.

(5) Some paragraphs required modification and some paragraphs were added to conform more closely to changes in technology.

The project on safety requirements for the manufacture, care, and use of horizontalinjection molding machines was initiated under the auspices of the Injection MoldingSection of the Machinery Division, and the Safety Committee of the Molders Divisionof the Society of the Plastics Industry, Inc. (SPI).

Both divisions of the SPI have long been concerned with operator safety on plasticsprocessing equipment. Accordingly, each section of the divisions has established astandards development committee charged with the task of establishing necessarystandards.

A standard treating the manufacture, care, and use of horizontal injection moldingmachines is complicated by the wide variety and sizes of machines manufacturedand in use, the virtually infinite combinations of parts being produced, the productionmethods used, and the operating conditions existing in industry today.

The primary objective of this standard is to minimize hazards to personnel associatedwith machine activity by establishing requirements for the manufacture, care, anduse of these machines.

To accomplish this objective, the committee decided to approach the problem of ma-chine safety as follows:

The committee developed a list of hazards typical of HIMMs and listed these inclause 6 of this standard. For each hazard identified within the scope of the stan-dard, the committee assessed the potential severity of injury related to the hazard,the frequency of exposure to the hazard, and possible avoidance. This process in-volved discussion among the committee, and resulted in the recommended preven-tive control measure included in clauses 7 through 11 inclusive and additional Annexreference material. Compliance with this standard is considered to adequately con-trol hazards identified in clause 6. Other hazards not listed in clause 6 that can occurwith HIMMs may require additional preventive controls not included in this standard.

To assist in the interpretation of these requirements, responsibilities have been as-signed to the manufacturer, the remanufacturer, the modifier, and the employer.

Since no new requirements have been added to this standard for existing machines,clauses 9 and 11 are effective on the approval date of this standard.

Recognizing the impossibility of immediate updating of design and manufacturingmethods, clauses 7, 8, and 11 shall become effective one year after the approvaldate of this standard.

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Suggestions for improvement of this standard will be welcome. They should be sentto the Society of the Plastics Industry, Inc, 1667 K Street, NW, Washington, DC20006

Consensus for this standard was achieved by use of the Canvass Method.

The following organizations recognized as having an interest in the standardization ofhorizontal injection molding machines were contacted prior to the approval of thisstandard. Inclusion in this list does not necessarily imply that the organization con-curred with the submittal of the proposed standard to ANSI.

Aerospace Industries AssociationALCONAAlliance of American InsurersAmerican Insurance Services GroupIndustrial Safety Equipment AssociationNational Institute of Standards and TechnologyPackaging Machinery ManufacturersRobotic Industries AssociationRubber ManufacturersSociety of the Plastics Industry, Machinery Manufacturers DivisionSociety of the Plastics Industry, Molders Division

The Injection Molding Section, Standards Development Committee of the MachineryDivision, and the Safety Committee of the Molders Division of The Society of thePlastics Industry, Inc, which was responsible for this standard, had the followingmembers:

G. Atkinson, Chairman(Husky Corporation)

W. Bishop, Secretariat to the Committee(Executive Director, Machinery Division of the Society of the Plastics Industry)

J. Adamowicz (Arburg, Inc.)

P. Berry(Ube Machinery)

J. Ewing (Boy Machines)

S. Glover (Crucible Service Centers)

J. Hicks(Sumitomo/SHI Plastics Machinery)

C. Irick (EPCO Machinery)

D. Meckler(Bosch Rexroth)

L. Mills(Demag Plastics Group)

R. Monteith (Milacron, Inc.)

F. Pierson(Toshiba Machine Company)

S. Rickard(Visteon Corporation)

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J. Rexford(Taylor Industrial Services, HPM Division)

D. Ross (Netstal Machinery, Inc.)

D. Sten (Safety Consultant)

E. Wolfgang(Engel Machinery, Inc.)

vii

Explanation of Standard Format

American National Standard ANSI/SPI B151.1-2006 uses a two-column format toprovide both specific requirements and supporting information.

The left column, designated "Standard Requirements," is confined solely to these re-quirements and is printed in bold type

The right column, designated "Explanatory Information," contains only informationthat is intended to clarify the standard. This column is not a part of the standard.Where supplementary illustrations are required, they are designated as "illustrations."

Operating rules (safe practices) are not included in either column unless they are ofsuch a nature as to be vital safety requirements, equal in weight to other require-ments, or guides to assist in compliance with the standard.

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AMERICAN NATIONAL STANDARD ANSI/SPI B151.1-2007

American National Standard for Plastics Machinery –

Horizontal Injection Molding Machines – Safety Requirements for Manufacture, Care, and Use STANDARD REQUIREMENTS 1. Scope, Purpose, and Application

EXPLANATORY INFORMATION (Not part of American National Standard for Plastics machinery – Horizontal injection molding machines – Safety requirements for manufacture, care and use, ANSI/SPI B151.1-2007)

1.1 Scope The requirements of this standard shall apply to all HIMMs that process plastic materials and inject said material into a mold or molds held closed by a horizontally acting clamp. Safety requirements for the manufacture, care, and use of ancillary equipment or molds for HIMMs are not covered by this standard.

1.2 Purpose The purpose of this standard is to identify and address known hazards to personnel working on, or adjacent to, a HIMM.

1.3 Application

E1.3 Application Inquiries with respect to the application of, or substantive requirements of, this standard should be addressed to the Society of the Plastics Industry, Inc, 1667 K Street, NW, Washington, DC 20006.

1.3.1 New HIMMs The requirements in clauses 7, 8, and 11 of this standard shall apply to all new HIMMs, installed in the United States of America, that were

E1.3.1 New HIMMs Date of manufacture is understood to be the date the HIMM was complete and available for delivery to the employer.

ANSI/SPI B151.1-2007

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manufactured after the compliance date of this standard. The compliance date shall be one year after the approval date of this standard. The date of manufacture of the new HIMM (month and year) shall be affixed permanently and legibly to the HIMM along with the name of the manufacturer.

1.3.2 Remanufactured HIMMs The requirements in clauses 9 and 11 of this standard shall apply to all remanufactured HIMMs, installed in the United States of America, that were remanufactured after the compliance date of this standard. The compliance date shall be one year after the publish date of this standard. Date of remanufacture of the HIMM (month and year) shall be affixed permanently and legibly to the HIMM along with the name of the remanufacturer.

1.3.3 Existing HIMMs Existing HIMMs located in the United States of America prior to the approval date of this standard shall be in accordance with the requirements of clauses 9 and 11 of this standard.

1.3.4 All Installations An employer shall not permit a HIMM to be operated unless it is in compliance with this standard. The use shall be in accordance with clause 10 of this standard and shall be effective on the approval date of this standard.


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2 Referenced American National Standards This standard is to be used with the following American National Standards. ANSI Z535.3-2002, Criteria for Safety Symbols ANSI Z535.4-2002, Product Safety Signs and Labels ANSI Z97.1-2004, Safety Glazing Material Used in Buildings – Safety Performance Specifications and Methods of Test ANSI/ASME B20.1-1990, Safety Standard for Conveyors and Related Equipment SAE J1273-2002, Recommended Practices for Hydraulic Hose Assemblies ANSI/NFPA 79 -2002, Electrical Standard for Industrial Machinery

E2 Related Standards and Publications ANSI/SPI B151.27-2003, Safety Requirements for the Integration, Care, and Use of Robots with Horizontal Injection Molding Machines AN-108, SPI Recommended Guideline for Using Hydraulic Accumulators on Injection Molding Machines AN-134, Recommended Guideline for Technical Manuals Supplied with Plastics Machinery and Related Equipment AN-137, Recommended Guideline for Safety Signs for Plastic Machinery and Related Equipment AN-141, Harmonized International Safety Warning Signs for Injection Molding Machines ANSI/ASSE Z244.1-2003, Control of Hazardous Energy – Lockout/Tagout and Alternative Methods AN-104, SPI Noise Measurement Guideline AN-144, Guideline for Manufacture, Integration, and Use of Magnetic Clamping Systems on Horizontal Injection Molding Machines AN-143, SPI Recommended Guideline Entrained Gas Processing in Horizontal Injection Molding Machines

3 Definitions

3.1 Alarm: An indication that a failure or misadjustment of a device has occurred.

3.2 Automatic Cycle (Continuous): A selectable mode of operation of the HIMM that allows it to perform more than one cycle.

3.3 Barrel: The cylinder portion of the plasticizing unit within which the material is processed.

3.4 Clamp: That portion of the HIMM that holds the two halves of the mold and opens and closes the mold.

3.5 Control Circuit: This means controlling sequential motion/cycling of the HIMM by signaling the devices (hydraulic/pneumatic valving, electric servo motors, etc.) to affect HIMM motion.


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3.6 Core: Stationary and/or movable mold part that shapes a portion of a molded part.

E3.6 Core: Movable cores are normally moved (set) into position before injection takes place. Movable cores are normally (pulled) moved out of position to allow ejection of the molded part to occur.

3.7 Ejector: Any and all provisions built into the HIMM and/or mold for the release of the finished product from the mold.

E3.7 Ejector: The ejectors may be actuated by the motion of the HIMM platen or by hydraulic, electric and/or pneumatic circuitry integral with or independent of, the HIMM circuits.

3.8 Electric Motor Control Unit: Unit to control the movement and standstill of the electric motor, with or without integrated electronic device, e.g., frequency converter, contactor.

3.9 Electrically Driven Axis: System consisting of an electric motor, a motor control unit and any additional contactors.

3.10 Emergency Reverse Button. A button that, when depressed, will stop the platen closing motion and causes the platen to open at a reduced speed as long as the button is held depressed.

E3.10 Emergency Reverse Button: Platen closing motion ends when the mold halves touch.

3.11 Emergency Stop Button: A button that, when depressed, will stop all HIMM motion.

3.12 Employer: Any person who contracts, hires, or is responsible for personnel associated with HIMM operation and/or maintenance.

3.13 Guard: A physical barrier that prevents access to areas of the HIMM where known hazards exist.

3.14 Guard, Fixed: A guard requiring the use of tools for removal from the HIMM.

E3.14 Guard, Fixed: Electrical enclosures are covered by NFPA 79.

3.15 Guard, Movable: A guard that may be moved or removed without the use of tools. A movable guard requires an interlock(s).

E3.15 Guard, Movable: A hinged or sliding guard that is held in place with fasteners that require a tool for removal is considered a movable guard.

3.16 Hardwired Electrical Interlock: An electrical interlock that operates independently of any programmable device(s).

3.17 Hazard: A source of possible injury or damage to health.

3.18 HIMM: Horizontal Injection Molding Machine.


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3.19 Injection Unit: That portion of the HIMM that plasticizes and then injects material through a nozzle into a mold.

3.20 Instructions: Documentation for the installation, operation, care, and safe use of the HIMM.

E3.20 Instructions: See AN-34, Recommended Guideline for Technical Manuals Supplied with Plastics Machinery and Related Equipment

3.21 Interlock: An arrangement whereby the status of one control or mechanism, allows or prevents, the operation of another.


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3.22 Large HIMM: (a) Machines with horizontal clamping unit and tiebars (see Figure 1(a)) where:

- e1 or e2 > 1200 mm (47 inches) (b) machines with horizontal clamping unit without tiebars (see Figure 1(b)), where:

- a < 850 mm (33.5 in.) and e1 >400 mm (15.7 in.) and e2 > 400 (15.7 in.); or - e1 > 1200 mm (47 in.); or - e2 > 1200 mm (47 in.)

(a)

(b) Figure 1 – Large Machines with Horizontal

Clamping Unit with or without Tiebars

E3.22 Large HIMM: Tie bar spacing of greater than 1200 mm (47 inches) is the recognized dimension where whole body access to the mold area may be expected to allow the operator to manually remove the molded part. On machines with 1200 mm (47 inches) or less between tiebars, it is expected that the operator will remove the molded part by standing on the normal working surface outside the tie bars.


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3.23 Locking Device: A device that physically prevents the operator’s gate or guard from opening.

3.24 Lockout: The placement of a lockout device on an energy-isolating device, in accordance with an established procedure, ensuring that the energy-isolating device and the equipment being controlled cannot be operated until the lockout device is removed.

3.25 Manual Mode: A selectable mode of operation of the HIMM that allows individual HIMM motions to occur while commanded by a hold-to-run control device.

E3.25 Manual Mode: Exception: Set-up sequences in manual mode do not require hold-to-run control, e.g., auto purge, oil preheat, etc.

3.26 Manufacturer: A person(s) whose business is the manufacture of new HIMMs for installation in the United States of America.

3.27 Modification: For the purposes of this standard, any addition, deletion, conversion, or alteration to a HIMM that could affect personnel safety is considered a modification.

E3.27 Modification: A modification could affect such areas as control systems (electrical, hydraulic, pneumatic, etc.), HIMM motions, walkways, ladders, enclosures, platforms, guards, etc.

3.28 Modifier: Any person who performs a modification to a HIMM.

3.29 Mold Area: The area between the platens.

3.30 Mold Set or Setup Mode: A selectable mode of operation of the HIMM only allows individual HIMM motions to occur while commanded by hold-to-run control device and limits the speed of platen motion and injection forward motion for the purpose of mold installation and setting mold parameters.

E3.30 Mold Set or Setup Mode: In this mode of operation, as an example, the platen motion operates at reduced speed and/or pressure. Others motions, if desired, can operate using the same principle.

3.31 Monitoring Device: A device used to verify the function of another device.

3.32 No Cycle: A mode of operation of the HIMM that prevents all HIMM motions except power gate operation.

3.33 Normal Production: The utilization of the HIMM to perform its intended production function .

3.34 Operator: An individual who has been trained and authorized by the employer to perform production work on the HIMM.

3.35 Operator’s Gate: A movable barrier arranged to guard the operator’s side of the mold area.

E3.35 Operator’s Gate: The operator’s gate may be opened and closed with each HIMM semi-automatic cycle.

3.36 Plastic: Any material processed by the HIMM.

3.37 Platen: The stationary or moving member of a HIMM to which the mold is fastened.


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3.38 Platform, Maintenance: The purpose of a maintenance platform is to provide access to the mold area for maintenance functions and shall not be used during normal production.

3.39 Platform, Working: A working surface provided for the purpose of operator access to the mold area during normal production.

3.40 Power Circuit: The source of energy providing sequential motion or motion of the HIMM. For example, hydraulic oil flow for hydraulic systems, electrical power for electrical systems.

3.41 Presence-Sensing Device: A device that is capable of detecting an intrusion into a specified area.

E3.41 Presence-Sensing Device: Examples of presence-sensing devices include: safety mat, interlocked platform, photo-electric beam, or other similar devices.

3.42 Purging: The clearing of material from the injection unit to the atmosphere.

3.43 Rear Guard: A barrier arranged to guard the rear mold area.

3.44 Rebuild: Restoring a portion of the HIMM to its original purpose, capacity, or function including compliance with clauses 9 and 11 of this standard.

E3.44 Rebuild: Some change in original design may be required to comply with clauses 9 and 11 of this standard.

3.45 Remanufacture: The restoration of a complete HIMM in conformance with clauses 9 and 11 of this standard.

E3.45 Remanufacture: Remanufacture typically consists of some or all of the following:

1) complete dismantling of the HIMM; 2) cleaning and carefully inspecting all

parts; 3) reworking worn parts to as new

condition or replacing with new parts; 4) reconditioning slides, tiebars, ways,

linkages, cylinders, barrels, screws, etc. to meet applicable standards and guidelines;

5) completely reconditioning or replacing power system components to meet applicable standards and guidelines;

6) thoroughly inspecting all electrical and control systems and replacing components/systems as required; and

7) removing modifications that are not in conformance with clauses 9 and 11 of this standard and informing the employer of removal.

3.46 Remanufacturer: Any person whose business is the redesign and/or remanufacture of HIMMs for installation in the United States of America.

3.47 Repair: The restoration of a portion of a HIMM to original function using original design by replacement or reworking of worn or damaged parts.

E3.47 Repair: Repair may include such items as replacement or rework of an injection unit, barrel, screw, pump, motor, tie bars, clamp cylinders, valves, seals, gaskets, timers, relays, PLCs, etc.


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3.48 Robot: A multifunctional manipulator designed to move parts, end of arm tools, or specialized devices through variable programmed motions for the performance of a variety of tasks .

3.49 Safe Standstill: A state where unexpected movement is prevented by removal of energy supply.

3.50 Safety Related Input: Input to motor control unit, used to interrupt the energy supply to the drive of the electrically driven axis.

3.51 Safety Sign: A visual alerting device in the form of a sign, label, decal, placard, or other marking that advises the observer of the nature and degree of the potential hazard(s) that can cause injury or death.

3.52 Semi-Automatic Cycle (Single Cycle): A selectable mode of operation of the HIMM that allows it to perform one complete cycle and then stop.

3.53 Servicing and/or Maintenance: Workplace activities such as constructing, installing, setting up, adjusting, inspecting, modifying, and maintaining and/or servicing HIMM. These activities include lubrication, cleaning or unjamming of machines or equipment and making adjustments or tool changes where the employee may be exposed to the unexpected energization or startup of the HIMM or release of hazardous energy.

3.54 Set-Up: Any work performed to prepare HIMM to perform its normal production.

3.55 Setup Personnel: Individuals who are trained and authorized by the employer to prepare the HIMM and ancillary equipment for production.

3.56 Shall: The word “shall” is to be understood as denoting a mandatory requirement.

3.57 Should: The word “should” is to be understood as denoting a recommendation.

3.58 Single Cycle or Semi-Automatic Cycle: A selectable mode of operation of the HIMM that allows it to perform one complete cycle, then stop.

3.59 Standstill (Controlled Stop): Condition under which there is no movement of the parts of the machine with an electrically driven axis.


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3.60 Tagout: The placement of a tagout device on an energy-isolating device, in accordance with an established procedure, to indicate that the energy-isolating device and the HIMM being controlled may not be operated until the tagout device is removed.

3.61 Vapors: Gas or steam formed by processing plastic.

3.62 Vent Cover: A barrier covering the vent port opening.

3.63 Vent Port: An opening provided in the barrel to permit vapors to exit from the plastic material during processing.


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4 Care – Responsibility for

4.1 Instructions

4.1.1 Manufacturer It shall be the responsibility of the manufacturer to furnish instructions with the HIMM.

E4.1.1 Manufacturer See SPI AN-134 Recommended Guideline for Technical Manual Supplied with Plastics Machinery and Related Equipment.

4.1.2 Modifier It shall be the responsibility of any person modifying a HIMM to furnish instructions specific to the modification.

E4.1.2 Modifier See SPI AN-134, Recommended Guideline for Technical Manual Supplied with Plastics Machinery and Related Equipment.

4.1.3 Remanufacturer It shall be the responsibility of any person remanufacturing a HIMM to furnish instructions with the remanufactured HIMM.

E4.1.3 Remanufacturer See SPI AN-134, Recommended Guideline for Technical Manual Supplied with Plastics Machinery and Related Equipment.

4.2 Training of Maintenance and/or Setup Personnel It shall be the responsibility of the employer to ensure the original and continuing competence of personnel caring for, setting up, inspecting, and maintaining HIMMs.

4.3 Inspection and Maintenance It shall be the responsibility of the employer to establish and follow a program of periodic and regular inspections of HIMMs to ensure that they are in safe operating condition and proper adjustment. At the minimum, the employer shall follow the inspection and maintenance instructions provided by the manufacturer.

5 Manufacture, Remanufacture, Repair, Modification, and Rebuild

5.1 Responsibility

5.1.1 Manufacture The manufacture of new HIMMs shall be in accordance with clauses 7, 8, and 11 of this standard.


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5.1.2 Remanufacture The remanufacture of a HIMM shall be in conformance with Sections 9 and 11 of this standard. Remanufacture shall not reduce the level of safety existing on the HIMM at the time of manufacture.

5.1.3 Modification The modification made to existing HIMMs shall be in accordance with clause 11 and the parts of clause 9 of this standard that apply to the modification. Any modification shall not reduce the level of safety existing on the HIMM at the time of manufacture or remanufacture.

E5.1.3 Modification For the purpose of this standard, bringing a HIMM into conformance with the requirements of clause 9 (including the underlined items of clause 9 affected by the modification) is considered a modification.

5.1.4 Repair Repair shall not reduce the level of safety of the HIMM.

E5.1.4 Repair The intent of this subclause is to ensure that repairs are done properly with equivalent or better components.

5.1.5 Rebuild Rebuild of any portion of an existing HIMMs shall be in accordance with clause 9 and clause 11 of this standard. Rebuild shall not reduce the level of safety of the HIMM.


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6 List of Hazards Specific recognized hazards associated with HIMMs.

E6 List of Hazards A specific design could introduce hazards not covered by this standard.

6.1 Specific Machine Areas where Hazards Exist

Figure 2 – Horizontal Injection Molding Machine (HIMM) with Horizontal Clamping Unit and Horizontal Injection Unit, Shown without

Guards for Illustration Clarity (1) Mold area (2) Clamping mechanism area (3) Area of movement of core and ejector drive

mechanisms outside areas 1 and 2 (4) Nozzle area (5) Plasticizing and or injection unit area (6) Feed opening area (7) Area of the heater bands of the plasticizing

and/or injection cylinders (8) Parts discharge area (9) Hoses (10) Area inside the guards and outside the mold

area

6.1.1 Mold Area E6.1.1 Mold Area The area between the platens. (See Figure 2, area (1), also see 7.3.1.)


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6.1.1.1 Mechanical Hazards Crushing and/or shearing and/or impact hazards caused by:

• Movement of the platen; • Movements of the injection barrel(s) into the

mold area; • Movements of cores and ejectors and their

drive mechanisms; • Tiebar motion

6.1.1.2 Thermal Hazards Burns and/or scalds due to operating temperature of:

• The mold • Heating elements of the molds • Plasticized material released from/through the

mold.

E6.1.1.2 Thermal Hazards See 7.2.3 and 10.8.

6.1.2 Clamping Mechanism Area E6.1.2 Clamping Mechanism Area See Figure 2, area (2). See 7.3.2.

6.1.2.1 Mechanical Hazards Crushing and/or shearing and/or impact hazards caused by:

• Movement of the platen • Movement of the drive mechanism of the

platen • Movement of the core and ejector drive

mechanism.

6.1.3 Movement of Drive Mechanisms Outside the Mold Area and Outside the Clamping Mechanism Area

E6.1.3 Movement of Drive Mechanisms Outside the Mold Area and Outside the Clamping Mechanism Area See Figure 2 area (3). See 7.3.1 and 7.3.7.

6.1.3.1 Mechanical Hazards Mechanical hazards of crushing, shearing and/or impact caused by the movements of:

• Core and ejector drive mechanisms

6.1.4 Nozzle Area

E6.1.4 Nozzle Area The nozzle area is the area between the barrel and the sprue bushing. See Figure 2, area (4). See 7.3.3.


15

6.1.4.1 Mechanical Hazards Crushing, shearing hazards, and/or impact hazards caused by:

• Forward movement of the plasticizing and/or injection unit including nozzle

• Movements of parts of the power-operated nozzle shutoff and their drives

• Over-pressurization in the nozzle

6.1.4.2 Thermal Hazards Burns and or scalds due to operating temperature of:

• The nozzle • Plasticized material discharging from the

nozzle.


6.1.5 Plasticizing and/or Injection Unit Area

E6.1.5 Plasticizing and/or Injection Unit Area Area from the adaptor/barrelhead/end cap to the extruder motor above the sled including the carriage cylinders. See Figure 2, area (5).

6.1.5.1 Mechanical Hazards Crushing, shearing, and/or being drawn into hazards caused by:

• Unintentional gravity movements, e.g., for machines with plasticizing and/or injection unit positioned above the mold area

• The movements of the screw and/or the injection plunger in the cylinder accessible through the feed opening.

• Movement of the carriage unit

6.1.5.2 Thermal Hazards Burns and or scalds due to operating temperature of:

• The plasticizing and/or injection unit • The heating elements, e.g., heater bands • The plasticized material and/or vapors

discharging from the vent opening, feed throat or hopper.


6.1.5.3 Mechanical and/or Thermal Hazard Hazards due to reduction in mechanical strength of the plasticizing and/or injection cylinder due to overheating.

E6.1.5.3 Mechanical and/or Thermal Hazard See 7.3.5.5.


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6.1.6 Feed Opening Pinching and crushing between injection screw movement and housing.

E6.1.6 Feed Opening See Figure 2, area (6). See 7.3.5.1.

6.1.7 Area of the Heater Bands of the Plasticizing and/or Injection Cylinders Burns and or scalds due to operating temperature of:

• The plasticizing and/or injection unit • The heating elements, e.g., heater bands • The plasticized material and/or vapors

discharging from the vent opening, feed throat or hopper.

E6.1.7 Area of the Heater Bands of the Plasticizing and/or Injection Cylinders See Figure 2, area (7). See 7.3.5.2 and 10.8.

6.1.8 Parts Discharge Area

E6.1.8 Parts Discharge Area See Figure 2, area (8). See 7.3.6.

6.1.8.1 Mechanical Hazards Accessible through the Discharge Area Crushing, shearing and/or impact hazards caused by:

• Closing movement of the platen • Movements of cores and ejectors and their

drive mechanisms

6.1.8.2 Thermal Hazards Accessible Through the Discharge Area Burns and or scalds due to operating temperature of:

• The mold • Heating elements of the mold and • Plasticized material released from/through

the mold.

6.1.9 Hoses

• Whipping action caused by hose assembly failure

• Possible release of fluid under pressure that can cause injury

• Thermal hazards associated with hot fluid.

E6.1.9 Hoses See Figure 2, area (9). See 7.2.2.


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6.1.10 Area Inside the Guards and Outside the Mold Area Crushing and/or shearing and/or impact hazards caused by:

• Movement of the platen • Movement of the drive mechanism of the

platen • Movement of the core and ejector drive

mechanism • Clamp opening movement. •

E6.1.10 Area Inside the Guards and Outside the Mold Area See Figure 2, area (10). See 7.3.7.

6.2 Other Hazards/Hazardous Locations

6.2.1 Electrical Hazards Electric shock or burns due to contact with live conductive parts.

E6.2.1 Electrical Hazards See 7.2.4.

6.2.2 Electrical or Electromagnetic Disturbance Generated by the Motor Control Unit Electrical or electromagnetic disturbance that can cause failures in the machine control systems and adjacent machine controls

E6.2.2 Electrical or Electromagnetic Disturbance Generated by the Motor Control Unit See 8.9

6.2.3 Hydraulic Accumulators High pressure discharge

E6.2.3 Hydraulic Accumulators See SPI Recommended Guideline AN-108.

6.2.4 Power-Operated Gate Crush or impact hazards caused by the movement of the power-operated gates

E6.2.4 Power Operated Gate See 7.3.1.5.

6.2.5 Vapors and Gases Certain processing conditions and or resins can cause hazardous fumes or vapors.

E6.2.5 Vapors and Gases See 10.6.


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c ab

Danger point

7 Safety Requirements and/or Methods 7.1 General Guarding Reach over safety distances shall be in accordance with table 1 of Figure 3 unless otherwise specified. Reach through opening shall be in accordance with table 2 of Figure 4. Safety measure(s) shall be provided where hazards exist. Movable guards shall be interlocked to stop hazardous motion exposed by moving or removing the guard. Fixed guards shall require fasteners to attach guard in place and tools to install or to remove the fasteners.

E7.1 General Guarding Slot head fasteners are not recommended for attaching the fixed guards.

Table 1 – Safety Distance, Reach Over Protective Structure

Barriers less than 1000 mm (39 inches) in height are not included because they do not sufficiently restrict movement of the body. There shall be no interpolation of the values of this table. Consequently, when the known values of tables 1(a), 1(b), or 1(c) are between two values, the values to be used are those which provide the higher level of safety.

Figure 3 – Reach Over Protective Structure


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Table 2 – Safety Distance, Reach Through Opening

The following table gives the safety distance for regular openings. The dimensions of opening “e” correspond to the side of a square opening, the diameter of a round opening and the narrowest dimension of a slot opening. For openings > 120 mm (4.724 inch), table 1 shall be used.

Safety Distance “Sr” Opening “e” Slot Square Round

(mm) (in) (mm) (in) (mm) (in) (mm) (in) e ≤ 4 e ≤ 0.157 ≥ 2 ≥ 0.079 ≥ 2 ≥ .079 ≥ 2 ≥ .079

4 < e ≤ 6 0.157 < e ≤ 0.236 ≥ 10 ≥ 0.394 ≥ 5 ≥ .197 ≥ 5 ≥ .197 6 < e ≤ 8 0.236 < e ≤ 0.315 ≥ 20 ≥ 0.787 ≥ 15 ≥ .591 ≥ 5 ≥ .197 8 < e ≤ 10 0.315 < e ≤ 0.394 ≥ 80 ≥ 3.150 ≥ 25 ≥ .984 ≥ 20 ≥ .787 10 < e ≤ 12 0.394 < e ≤ 0.472 ≥ 100 ≥ 3.937 ≥ 80 ≥ 3.150 ≥ 80 ≥ 3.150 12 < e ≤ 20 0.472 < e ≤ 0.787 ≥ 120 ≥ 4.724 ≥ 120 ≥ 4.724 ≥ 120 ≥ 4.724 20 < e ≤ 30 0.787 < e ≤ 1.181 ≥ 850

(1) ≥ 33.465

(1) ≥ 120 ≥ 4.724 ≥ 120 ≥ 4.724

30 < e ≤ 40 1.181 < e ≤ 1.575 ≥ 850 ≥ 33.465 ≥ 200 ≥ 7.874 ≥ 120 ≥ 4.724 40 < e ≤ 120 1.575 < e ≤ 4.724 ≥ 850 ≥ 33.465 ≥ 850 ≥ 33.465 ≥ 850 ≥ 33.465

(1) If the length of the slot opening is ≤ 65 mm (2.56 inch) the thumb will act as stop and the safety distance can be reduced to 200 mm (7.87 inch).

Figure 4- Safety through opening

Opening e Danger Zone

Sr

Safety Distance


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7.2 General Safety Requirements

7.2.1 Window When a window is used in a gate or guard to provide visibility, the window material shall be polycarbonate or tempered glass and shall meet the requirements of ANSI Z97.1.

7.2.2 Hoses Flexible hoses with pressure higher than 50 bar (725 psi), and their connections, shall be designed to prevent unintentional detachment by meeting the following requirements:

• Hoses and hose assemblies selection and installation shall comply with the specifications in SAE standard SAE J1273.

E7.2.2 Hoses See 10.13

7.2.3 Thermal Hazards Guard or warning tag against hot surfaces above 175 F (80 C) shall be provided.

E7.2.3 Thermal Hazards See 7.3.5.2 for barrel cover requirements.

7.2.4 Electrical Requirements HIMMs shall be in accordance with the requirements of ANSI/NFPA 79.

7.2.4.1 Safety Circuit Performance For Type II and Type III interlocks, safety shall be maintained in the case of a single fault. The safety circuit shall be designed, constructed and applied such that any single component failure shall lead to the shutdown of the system in a safe state and prevent the subsequent automatic operation until that component failure has been corrected. Safety circuits shall be hardware or a software/firmware based controller. When safety related software and firmware based controllers are used in place of hardware based components, they shall be listed for such use. In either case, the monitoring shall:

(a) Generate a stop motion signal if a fault is detected.

(b) Provide a warning if the hazard remains after cessation of motion.

(c) Maintain a safe state until the fault is cleared.

E7.2.4.1 Safety Circuit Performance See 7.3. For example, if relays controlled by the position switch(es) are used for the purpose of contact multiplying, monitoring of these relays is necessary.


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(d) Detect the single fault at time of failure. If

this is not practical, the failure shall be detected at the next demand upon the safety function, and If a software/firmware controller is not listed for use in safety related control functions, then each position switch shall be connected to its own input module, or if a common input module is used, the inverse signals of both position switches shall be inputted and any fault in the input circuits shall be automatically recognized.

7.2.4.2 Machine Grounding The machine and all exposed, noncurrent-carrying conductive parts, material, and equipment likely to be energized shall be effectively grounded. Where electrical devices are mounted on metal mounting panels that are located within nonmetallic enclosures, the metal mounting panels shall be effectively grounded. The above items shall be interconnected to the equipment grounding (protective) conductor terminal.

7.2.4.3 Stop Function Each HIMM shall be equipped with a either Category 0 or Category 1 stop. Category 0 and Category 1 stops shall be operational regardless of operating modes. Stop function shall operate by de-energizing that relevant circuit and shall override related start functions. Where required, provisions to connect protective devices and interlocks shall be provided. Where applicable, the stop function shall signal the logic of the control system that such a condition exists. The reset of the stop function shall not initiate any hazardous conditions.

E7.2.4.3 Stop Function Category 0 is an uncontrolled stop by immediately removing power to the machine actuators. Category 1 is a controlled stop with power to the machine actuators available to achieve the stop then remove power when the stop is achieved.

7.2.4.4 Emergency Stop Emergency stop shall be initiated by a single human action. In addition to the requirements for stop functions, emergency stop shall have the following requirements: (1) It shall override all other functions and operations in all modes.


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(2) Power to the machine actuators, which causes a hazardous condition(s), shall be removed as quickly as possible without creating other hazards (e.g., by the provision of mechanical means of stopping requiring no external power, by reverse current braking for a Category 1 stop). (3) Reset of an emergency stop circuit shall not initiate a restart. (4) It shall function as either a Category 0 or a Category 1 stop. Where a Category 0 stop is used for the emergency stop function, it shall have only hardwired electromechanical components. Exception: Electronic logic (hardware or software) that meets NFPA 79 requirement can also be used. Where a Category 0 or a Category 1 stop is used for the emergency stop function, final removal of power to the machine actuators shall be ensured and shall be by means of electromechanical components. Where relays are used to accomplish a Category 0 emergency stop function, they shall be nonretentive relays. (5) Emergency stop pushbuttons shall be located at each operator control station or where motion can be initiated and at other locations where emergency stop is required. (6) Pushbutton-type devices for emergency stop shall be of the self-latching type and shall have positive (direct) opening operation. (7) Emergency stop switches shall not be flat switches or graphic representations based on software applications. (8) It shall not be possible to restore an emergency stop circuit until the emergency stop device has been manually reset. Where several emergency stop devices are provided in a circuit, it shall not be possible to restore that circuit until all emergency stop devices that have been operated have been reset.


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(9) Actuators of emergency stop devices shall be colored RED. The background immediately around pushbuttons and disconnect switch actuators used as emergency stop devices shall be colored YELLOW. The actuator of a pushbutton-operated device shall be of the palm or mushroom-head type. The RED/YELLOW color combination shall be reserved exclusively for emergency stop applications. 7.2.4.5 Interlock Switches Where doors or guards have interlocked switches used in circuits with safety related functions, the interlocking devices shall have either positive (direct) opening operation, or provide similar reliability and prevent the operation of the equipment when the doors or guards are open (difficult to defeat or bypass). Exception: When two interlock switches are used together in a Type II or Type III interlock, one of the switches will not operate in a positive mode.

7.2.4.6 Continuity of the Grounding Circuit One of the following methods shall be used to verify the continuity of the equipment grounding circuit: (1) Use an impedance measuring device, take into account any impedance in the measuring circuit. The measured impedance shall be 0.1 ohm or less. (2) Apply a current of at least 10 amperes, 50 Hz or 60 Hz, derived from a Safety Extra Low Voltage (SELV) source. The tests are to be made between the equipment grounding protective earthing (PE) terminal and relevant points that are part of the equipment grounding (protective bonding) circuit; the measured voltage between the equipment grounding protective earthing (PE) terminal and the points of test is not to exceed the values given in Table 3. Table 3 – Verification of Continuity of the Equipment Grounding (Protective Bonding) Circuit

Minimum Equipment Grounding (Protective Bonding) Conductor Cross-Sectional Area of the Branch Under Test (AWG)

Voltage Drop* (V)

18 3.3 16 2.6 14 1.9 10 1.4 > 8 1.0

*Values are given for a test current of 10 amperes


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7.2.4.7 Electrical Disconnects A lockable supply circuit disconnecting means shall be provided for each incoming supply circuit to the HIMM.

7.2.4.8 Short Circuit / Branch Circuit Protection Supplementary overcurrent protective devices shall not be used as a substitute for branch-circuit overcurrent protective devices.

7.2.4.9 Barrel Heaters Off-On Function Selection Removal of the electrical power to all energized conductors supplying power to the barrel heaters shall be accomplished by electro-mechanical means when the barrel heaters are turned off.

E7.2.4.10 Barrel Heaters Off-On Function Selection The intent of this clause is to ensure the removal of electrical power from the barrel heaters when the barrel heaters are turned off using the barrel heaters off-on selection because some barrel heater circuits may not disconnect all the energized conductors.

7.2.5 Cycle Initiation with Manual Operators Gate Closure of the operator’s gate can initiate motion providing:

• Whole body access is prevented between the mold area and gate with the gate closed and;

• The machine is not a large HIMM (see 3.22).

7.3 Additional Safety Requirements and/or Methods in Specific Machine Areas

Safety circuit and its monitoring function described below shall comply with 7.2.4.1

A) Type I Interlock (Figure 5) An interlock consisting of one position sensor that is positively actuated when the guard opens and positively interrupts the energy supply to the device producing the hazardous motion.

The single fault safety requirement stated in 7.2.4.1 does not apply to the position switch or the main shutoff device

B) Type II Interlock (Figure 6) An interlock consisting of two position sensors that interrupt the energy supply to the device producing the hazardous motion when the guard opens.

One position sensor shall be positively actuated and positively interrupt the energy supply to the device producing the hazardous

E7.3 Additional Safety Requirements and/or Methods in Specific Machine Areas


25

motion when the guard opens. The second position sensor shall be released when the guard opens interrupting the energy supply to the device producing the hazardous motion.

The guard position sensors are monitored to ensure that:

• Each guard position sensor changes state each time the guard is opened or closed.

• The state of each position sensor changes in predetermined sequence with respect to opening and closing the guard.

• Each guard position sensor must be in predetermined state to permit the hazardous motion.

C) Type III Interlock with Hydraulic/Pneumatic Second Shutoff Device (Figures 7 and 8)

An interlock consisting of Type II interlock as described above and a hydraulic (or pneumatic) second shutoff device that prevents the platen from closing when the operator gate is not closed. The second shutoff device shall interrupt the flow of hydraulic fluid (or pneumatic) to the clamp closing cylinder(s). The shutoff device shall be an additional valve or a pilot stage of the main shutoff device, which is one of the following:

• Positively and directly actuated by the operator’s gate when the gate is opened.

• Controlled by an independent hardwired limit switch which is positively and directly actuated by the operator gate when the gate is opened.

• Controlled by a pilot valve that is directly actuated by the operator’s gate when the gate is opened.

• Controlled by a pilot valve, which is controlled by an independent hardwired limit switch which is positively and directly actuated by the operator’s gate when the gate is opened.

When the additional valve is controlled by hardwired limit switch, the limit switch shall have positive opening contacts and the connection between the hardwired limit switch and the additional valve shall be via a hardwired circuit (possibly a relay) and shall be independent of the programmable controller.

See annex A regarding the use of proportional valves. See 8.3 for electrically driven platen motion.


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The shutoff device shall be provided with an electrical device for monitoring its operation. The following shall be automatically monitored during each cycle of movable guard:

• The switching of the position switches of the guard acting on the control circuit.

• The switching of the position of the additional valve.

• The switching of the position of the additional position switch and/or the pilot valve. Where this is automatically monitored by the position switching of the additional valve, the additional monitoring of the additional position switch and/or pilot valve is not required.

Monitoring of the device shall be in accordance with 7.2.4.1.


27

5 1

34

2 S1

Type III withdirect operatedsecond shutoffdevice[7]

S2

6

7

Figure 5

Example of Type I – Purge Guard

Figure 6

Example of Type II-Other Guard

Figure 7

Example of Type III- Operator Gate- Direct operated second shutoff device [7]

Figure 8

Example of Type III- Operator Gate- Electrically operated second shutoff device [7]

[1] power source [2] control circuit [3] guard closed [4] guard open [5] main shutoff device [6] monitor circuit [7] second shutoff device [S1] limit switch 1 [S2] limit switch 2 [S3] limit switch 3

The examples used are for illustration purpose only. Many methods and devices can be used to achieve the same degree of reliability and functionality.

5 1

34

2 S1

Type I

5 1

34

2 S1

Type II

S2

6

Control Circuit

Control voltage

InjectionForwardSolenoidPLC

Purge GuardLimit switch

Positive breaking symbol on the limit switch

Switch shown with purge guard closed.Switch opens when guard is not closed

5 1

34

2 S1

Type III withelectrically operatedsecond shutoffdevice [7]

S2

6

7

S3

Control voltage

Operator Gate Switches

Switches shown with operator gate closed


S1 S2

Control Circuit

PLC

7

5

Platen closehydraulic or pneumatic circuit

Monitoring Circuit

Control voltage

Operator Gate Switches

Switches shown with operator gate closed


S1 S2

Control Circuit

PLC 5

Platen closehydraulic or pneumatic circuit

Monitoring CircuitS3

7

Monitoring Circuit

Control voltage

Guard Switches

Shutoff Deviceor MotorContactor

Status OK

Control Circuit

Switches shown with guard closed


S1 S2


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7.3.1 Mold Area

7.3.1.1 Operator’s Gate Access to the mold area shall be prevented by the use of an operator’s gate. When in the closed position the operator’s gate shall prevent access to the mold area.

• Reaching over the operator’s gate shall be prevented by the guards addressed in 7.3.1.7. or by distance in Table 1, Figure 3.

• Reaching around or under or through the operator’s gate while standing on the working surface shall be prevented by the use of guards in accordance with 7.1.

The operator’s gate shall be interlocked to prevent hazardous motion using Type III interlocks and a mechanical device described in 7.3.1.4

E7.3.1.1 Operator’s Gate See 8.3.2.1 for electrically driven platen movement.

7.3.1.2 Hydraulic (or Pneumatic) Device For Hydraulic or Pneumatic shutoff device, see 7.3(C).

7.3.1.3 Electrical Interlock The electrical interlock portion of Type III described in 7.3 shall interrupt and/or prevent:

• Clamp closing • Clamp opening (see 7.3.1.8 for motion/no

motion exception) • Screw rotation (see 7.3.4 for shutoff nozzle

exception) • Forward movement of the screw or plunger • Forward movement of the injection

carriage • Ejector and core motion.

E7.3.1.3 Electrical Interlock See 7.3.1.8 for motion/no motion exception.

7.3.1.4 Mechanical Device A mechanical device shall be provided such that when the operator’s gate is opened sufficiently to permit access to the mold area, the platen will be physically prevented from closing. A monitoring device that complies with 7.2.4.1 shall be provided to check the operation of the mechanical device. If improper operation is detected, the movement shall be inhibited and an alarm shall be activated. No additional cycle is possible until the alarm condition is cleared.

E7.3.1.4 Mechanical Device For an electrically actuated mechanical device, switch 1 and switch 2 from the Type III interlock in Figure 7 or 8 can be used. The intent of this device is to provide a physical obstruction to impending closing motion of the moving platen. Some platen closing motion may occur before the mechanical device is fully engaged. The mechanical device is not intended to resist clamp-up force.


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The mechanical device may include but is not limited to:

• Ratchet bar • Friction-type device

7.3.1.5 Power-Operated Gate If a power-operated gate is used, the exposed leading edge(s) shall incorporate a pressure-sensitive switch or equivalent device such that if the switch or device is activated the gate motion stops or reverses. The pressure-sensitive device shall be designed into the circuit such that a failure of the device duplicates actuation of the switch. Closure of a power-operated gate shall require direct and continuous actuation by the operator and shall not directly initiate a HIMM cycle. The position of the manual controls for the power operated gate shall provide a clear view of the mold area.

E7.3.1.5 Power-Operated Gate The standard promotes a two-event approach to the initiation of the HIMM cycle;

1. Closure of the power-operated gate 2. Cycle initiation (can be the reactuation of

the close button or a second button). See clause 8 for electrically driven platen motion.

7.3.1.6 Rear Guard (Sides of the Machine where a Cycle Cannot Be Initiated) An interlocking guard with two position switches as shown in Type II and described in Figure 6 shall be used at the sides where a cycle cannot be initiated. Opening the guard shall:

• Stop all motions • Shut off the energy source for all motions.

When the guard is returned to its closed position manual resetting of the controls shall be necessary at the side of the machine where a cycle can be initiated. Alternatively, the rear guard may be replaced by an additional operator’s gate or movable guard with operator's gate interlocks. (See 7.3.1.1 through 7.3.1.4.) If the rear guard is mechanically connected to the front operator’s gate such that the rear guard cannot be opened without opening the front operator’s gate, then the interlocks on the operator’s gate provide adequate protection for the rear side of the mold area.

E7.3.1.6 Rear Guard (Sides of the Machine Where a Cycle Cannot Be Initiated)

See 8.3.2.2 for electrically driven platen movement.


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7.3.1.7 Top Guard A top guard shall be installed when it would be possible for a person standing on the floor or working platform to reach over the top of the operator’s gate or rear guard into a hazardous area. See Table 1. If the top guard is movable, an interlocking guard with two position switches as shown in Type II and described in Figure 6 shall be used. Opening the guard shall:

• Stop all motion • Shut off the energy source for all motions.

When guard is returned to its closed position manual resetting of the controls shall be necessary at the side of the machine where a cycle can be initiated. If the top guard is mechanically connected to the front operator’s gate such that the top guard can not be opened without opening the front operator’s gate, then the interlocks on the operator’s gate provide adequate protection for the top side of the mold area.

7.3.1.8 Motion/No Motion Option for Platen, Core, and Ejector When the motion/no motion option is provided the following requirements shall apply:

1. The selection between motion mode and no motion mode shall be accomplished by the use of a lockable switch. The key is removable only in the “no motion” position.

2. Changing the machine mode of operation or pump shutdown shall require re-initiation of motion operation mode.

3. Safety signs shall be used to warn of the motion that occurs when motion is selected.

4. When “no motion” mode is selected the HIMM shall meet the requirement of 7.3.1.3.

5. When “motion” mode is selected: A. The “motion” mode shall be

effective only in the semi-automatic mode of operation. No movement shall be permitted in manual or automatic modes of operation.

B. For large HIMMs, ejector forward and core out (pull) motion are allowed with the operator’s gate open. Platen movement is not allowed with the operator’s gate open.

E7.3.1.8 Motion/No Motion Option for Platen, Core, and Ejector

It is recognized that some special molds require that the part be manually lifted from the mold, in single or semi-automatic cycle.

The intent of the lockable switch is to require the employer to implement the requirements of 10.9.

See 8.7 for the electric HIMM.


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C. For non large HIMM’s, platen open, ejector forward and core out (pull) motions are allowed with the operator’s gate open.

D. If a single component failure can cause the platen to close with the operator’s gate open, the mechanical device must be engaged whenever the operator’s gate is open. (see 7.3.1.4)

E. Access to shearing and pinching points behind the mold mounting surface of the movable platen shall be prevented.

D. An example of single component failure is separation of the piston from the cylinder rod in a hydraulic cylinder.

7.3.2 Clamping Mechanism Area This area shall be guarded by either:

• A fixed guard or • Movable interlocking guard with two

position switches as shown in Type II and described in Figure 6.

Opening the movable guard shall interrupt the cycle and stop all motion in the clamp mechanism area. If the guard is movable and it is possible to stand between the guard and the clamp mechanism, an emergency stop button shall be provided inside the guarded area. Use the dimension in Figure 10 for the clamp mechanism area.

E7.3.2 Clamping Mechanism Area For electrically driven platen motion, see 8.3.2.2.

7.3.3 Nozzle Area (Purging Protection) A solid (not perforated) guard shall be provided to enclose the front, rear, and top of the purging area on the injection side of the stationary platen. Interlock using Type I described in Figure 5 shall be provided. Purging shall be prevented with the operator’s gate open. When the guard is not in position it shall prevent:

• Screw rotation • Screw or plunger forward motion • Injection carriage forward motion

The nozzle tip shall be within the purge guard when purging is possible. This requirement does not apply when the injection carriage is swiveled out of its normal operating position.

E7.3.3 Nozzle Area (Purging Protection) Fixed and movable guards that enclose all sides of the injection unit and the top of the nozzle area may be considered purging protection. For electrically driven carriage or screw motion, see clause 8.

7.3.4 Nozzle Shutoff Device Screw rotation shall be allowed with the operator’s gate open only when the nozzle shutoff device prevents material discharge.


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7.3.5 Plasticizing and/or Injection Unit Area

(Mechanical and Thermal Hazards)

7.3.5.1 Feed Openings All feed openings for plastic materials shall be guarded against inadvertent insertion of hands. See Table 2 of Figure 4 for opening and safety distance. Safety signs shall be used in this area.

E7.3.5.1 Feed Openings A fixed hopper can serve as a fixed guard for the feed throat opening to prevent inadvertent insertion of hands. See clause B4 of annex B for clearing blocked feed throat.

7.3.5.2 Injection Barrel Covers A cover or barrier shall be provided to prevent inadvertent contact with high temperatures when the injection unit is in the normal operating position. If the cover or the barrier surface temperature is above 175°F (80°C), safety signs shall be provided on or adjacent to injection barrel covers.

E7.3.5.2 Injection Barrel Covers Insulating blankets may serve as the cover or barrier to prevent inadvertent contact with high temperature.

7.3.5.3 Injection Unit Swivel Interlock Whenever the injection unit is swiveled out of the normal operating position, screw or plunger forward motion shall only be possible in manual mode. Maximum screw or plunger forward speed shall be 13 mm/sec (0.5 in/sec).

E7.3.5.3 Injection Unit Swivel Interlock The purpose of reduced screw or plunger forward speed is to permit screw removal/maintenance. See clause B5 of annex B for screw removal procedure.

7.3.5.4 Barrel Vent Cover A cover shall be provided over the vent port to protect personnel from hot plastic and/or vapors that may be expelled.

E7.3.5.4 Barrel Vent Cover See 10.6 for vapor hazards and 10.8 for personal protective equipment. See 10.5 for barrel vents ports.

7.3.5.5 Temperature of Plasticizing and/or Injection Barrel (Cylinder)

The temperature of the plasticizing and/or injection barrel (cylinders) shall be automatically monitored to ensure that the maximum design temperature is not exceeded. The energy supply to all barrel heating elements shall be automatically interrupted:

• If the maximum design temperature is exceeded; or

• In case of a fault in the temperature control.

The HIMM shall control and automatically monitor the temperature of the plasticizing and/or injection barrel (cylinder) to ensure that the maximum/minimum set point is not exceeded.

E7.3.5.5 Temperature of Plasticizing and/or Injection Barrel (Cylinder) The intent of this requirement is to maintain injection barrel assembly integrity. See 10.10 for interrupted cycle. See 10.3 for Set Point.


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7.3.5.6 Vertical Injection Units In order to prevent unintentional gravity descent, injection units positioned above the mold area shall be provided with a restraint device.

E7.3.5.6 Vertical Injection Units For example, for a vertical hydraulically operated movement, a restraint valve fitted preferably directly on the cylinder, or as close as possible to the cylinder using flanged (flared or welded) pipe work or flared unions only should be used. The means of preventing falling of the injection carriage, screw, or plunger may include devices such as a blocking valve, a mechanical restraint, counter balance/weight pulley system or a friction device.

See clause 8 for electrically driven vertical injection units.

7.3.6 Parts Discharge Opening The parts discharge opening (front and rear) shall be guarded to prevent access to hazards in the mold area through this opening. The dimensions in Figure 9 shall be met with the use of fixed or movable guards, if necessary.

Figure 9 - Parts Discharge Opening If a < 100 mm (3.9 inches), then b ≥ 550 mm (21.6 inches) or If a ≥ 100 mm (3.9 inches), then b ≥ 550 – a.

E7.3.6 Parts Discharge Opening The presence of a conveyor or chute may function as a guard if it provides the same level of protection. (See ANSI/ASME B20.1.) See 10.4. Permanent tubing or other fixed machine member may provide some or all of this guarding requirement.


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7.3.7 Area Inside the Guard and Outside the Mold Area

Figure 10 – Area Inside the Guard and Outside the Mold Area The mold area guards shall be designed so that it is not possible for a person to stand on the floor between the guards and the mold area. This requirement is met if the dimension in Figure 10 (less than or equal to 150 mm (6 inches)) is achieved.

E7.3.7 Area Inside the Guard and Outside the Mold Area

It is not considered possible for a person to stand between the Operator’s gate or rear guard and the mold area if this distance is less than 150 mm (6 inches). This dimension can be accomplished with the use of a horizontal bar(s) attached to the manually operated operator’s gate or rear guard.

7.3.7.1 Area between the Operator Gate and Mold Area Where it is possible for persons to stand between the operator gate(s) and the mold area:

• An emergency stop Category 0 shall be provided in a location that is readily accessible from this area

• Additionally one of the following devices shall be provided:

a) Gate Block A mechanical device shall be provided which operates with each opening movement of the operator’s gate to prevent the unintentional return of the gate to the closed position. The disengagement of this mechanical device and closure of the operator’s gate shall occur only by the direct and continuous action of the operator.

The position from which this device is disengaged and the operator’s gate is actuated shall allow a clear view of this area. A monitoring device that complies with 7.2.4.1 shall be provided to check the operation of the mechanical device. If improper operation is

E7.3.7.1 Area between the Operator Gate and Mold Area See 8.3 for electrically driven platen motion.


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detected, the HIMM cycle shall be inhibited and an alarm shall be activated. Exception: where a floor entry mounted robot is used, disengagement of this device and closure of the gate may be initiated by a robot signal. OR b) Double Acknowledgment System A double acknowledgment system shall consist of a push button (#1) located inside the operator’s gate that provides a clear view of the mold area and a second push button (#2) located outside the operator’s gate with a clear view of this area, which cannot be actuated from inside the closed operator’s gate. The start of a cycle shall be possible only after the following sequence has been completed within a time interval prescribed by the HIMM manufacturer: 1) Push button #1 2) Close operator’s gate 3) Push button #2 – lcycle initiation A monitoring circuit that complies with 7.2.4.1 shall be provided to check the operation of each push button. If improper operation or sequencing is detected, the HIMM cycle shall be inhibited and an alarm shall be activated. OR c) Presence-Sensing Device Actuation of the presence-sensing device(s) shall prevent the initiation of platen motion, powered operator’s gate closing motion, core and/or ejector motion, and injection motion. Actuation of the presence-sensing device(s) during platen closing shall stop all motion, shut off the energy source for all motions, and require the manual resetting of the HIMM before a new cycle can be initiated.

See ANSI/SPI B151.27, American National Standard for Plastic Machinery – Robots Used with Horizontal and Vertical Clamp Injection Molding Machines. b) Double Acknowledgment System The power-operated gate close button can also act as the cycle initiation, provided it is pushed a second time after the gate is closed.

7.3.7.2 Machines Where Whole Body Access Is Possible between the Rear Guard and the Mold Area Where it is possible to stand between the rear guard and the mold area, an emergency stop, Category 0, shall be provided in this area.


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7.4 Large HIMM

E7.4 Large HIMM See 3.22.

7.4.1 Large HIMM without Platform The following safety devices shall be provided: a) An Emergency stop, Category 0, inside the operator’s gate and inside the rear guard and either b) Operator’s gate block: A mechanical device as described in 7.3.7.1(a) or c) Operator’s gate double acknowledgment system: A double acknowledgment system as described in 7.3.7.1(b)

7.4.2 Large HIMM with Working Platform When the HIMM is supplied with a working platform in the mold area, in addition to the requirements of 7.4.1 one or more presence-sensing device(s), such as a safety mat, an interlocked platform, a photo electric beam or other similar safety rated device, shall be provided and positioned such that a person standing on the platform would activate the device(s). Actuation of the presence-sensing device(s) shall prevent the initiation of platen motion, powered operator’s gate closing motion, core and/or ejector motion, and injection motion. Actuation of the presence-sensing device(s) during platen closing shall stop all motion, shut off the energy source for all motions and requires the manual resetting of the HIMM before a new cycle can be initiated. Motion, as provided for in 7.3.1.8 may be permitted when the presence-sensing device is actuated if this motion does not in itself create a hazard.

7.4.3 Large HIMM with Maintenance Platform The purpose of a maintenance platform is to provide access to the mold area for maintenance functions and shall not be used during normal production. A maintenance platform that is placed into the mold area on a temporary basis shall only be installed after the machine is locked out and tagged out. A maintenance platform that is

E7.4.3 Large HIMM with Maintenance Platform See clause B.1 of annex B for Lockout/Tagout Information.


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permanently left in the mold area during production, thus acting as a working platform, shall be interlocked as described in 7.4.2 above. A maintenance platform that can be moved out of the mold area, where it cannot act as a working platform, shall be interlocked with two position switches as shown in Type II and described in Figure 6. The interlock shall stop all machine motion and shut off the power circuit when it is moved into an area where it can act as a working platform. 7.5 HIMM with Additional Injection Units

7.5.1 Hazards from Additional Injection Unit Mechanical hazards in the mold area may become accessible due to alteration or removal of HIMM guarding to accommodate the extra injection unit. The mold area hazards are the same as shown in 6.1.

1. Hot plastic splatter from the additional nozzle(s) during purging.

2. Operator exposure to hot plastic splatter from the additional nozzle when the operator's gate is open.

3. Crushing, shearing and/or drawn into hazards caused by unintentional movement of a vertical injection carriage due to gravity.

4. Burn hazards from gravity acting on the injection screw or plunger in a vertical injection unit.


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7.5.2 Additional Injection Unit at the Rear Side of the Machine If the HIMM rear guard is altered or removed to accommodate an additional injection unit, additional fixed or movable guards shall be added to provide protection from mold area hazards. If a movable guard is added which allows access to mechanical hazards in the mold area, an interlocked guard with two position switches as shown in Type II and described in Figure 6 or Type III, shall be used. If a fixed guard is added, no interlocking is required.

E7.5.2 Additional Injection Unit at the Rear Side of the Machine This clause deals with additional injection units which inject from locations outside of the normal HIMM purge guard, e.g., horizontally through the rear guard or vertically from above, as shown in typical locations 3 through 8 in the Illustration 1 below. Additional injection locations are possible.

Illustration 1 – Top View

See clause 8 for electrically driven injection units.

7.5.3 Purging Protection Guarding shall be provided to shield personnel from material being purged from the additional injection unit. The HIMM structure, guarding, or closed mold may act in whole or in part to meet the purging protection requirement. If guarding is movable, it shall be interlocked in accordance with Type I (Figure 5) to prevent screw rotation, screw or plunger forward, and injection carriage forward motion. If this movable guarding also allows access to mechanical hazards in the mold area, an interlocking guard with two position switches as shown in Type II and described in Figure 6 or Type III (Figure 7 or 8) shall be provided.

E7.5.3 Purging Protection Consideration should be given to providing means for easy purge material removal. See clause 8 for electrically driven injection units.

7.5.4 Splatter Protection If the additional injection unit exposes the HIMM operator to inadvertent splatter of hot plastic when the mold and operator’s gate are open, protection shall be provided by one or more of the following:

Fixed guarding: A movable guard which provides a physical barrier in front of the nozzle when the operator’s gate is open. This guard shall be interlocked according to type I (Figure 5) to prevent clamp opening until this guard is in place. The movable guard shall be monitored for correct

E7.5.4 Splatter Protection The purpose of these additional measures is to protect the operator from inadvertent splatter of hot plastic from the nozzle of the additional injection unit by use of a physical barrier. If the additional injection unit can only inject into the stationary side of the mold (i.e. it is not adjustable for injection at other positions, such as the parting line or the moving side of the mold), the mold may provide the guarding required by this clause.


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operation. If improper operation is detected, all motion shall stop and the machine shall energize an alarm condition. No additional cycle is possible until the alarm condition is cleared. Monitor circuit shall comply with 7.2.4.1.

When the operator’s gate is opened, screw rotation, screw or plunger forward, and injection unit forward motions are prevented for all injection units by the operator’s gate interlocks. See clause 8 for electrically driven injection units.

7.5.5 Vertically Mounted Injection Unit In order to prevent unintentional gravity descent, injection units positioned above the mold area shall be provided with a restraint device.

E7.5.5 Vertically Mounted Injection Unit For example, for a vertical hydraulically operated movement, a restraint valve fitted preferably directly on the cylinder, or as close as possible to the cylinder using flanged (flared or welded) pipe work or flared unions only should be used. The means of preventing falling of the injection carriage, screw, or plunger may include devices such as a blocking valve, a mechanical restraint, counter balance/weight pulley system or a friction device.

See clause 8 for electrically driven vertical injection units.

7.6 Two Platen HIMM

E7.6 Two Platen HIMM See Figure 2, area (2).

7.6.1 Area behind the Moving Platen This area shall be guarded by either:

• A fixed guard or • Movable interlocking guard with two

position switches as shown in Type II and described in Figure 6.

Opening the movable guard shall interrupt the cycle and stop all motion in the clamp mechanism area. If a movable guard is used, an emergency stop button shall be provided inside the guarded area near the movable guard. When the guard is returned to its closed position manual resetting of the controls shall be necessary at the side of the machine where a cycle can be initiated.

E7.6.1 Area behind the Moving Platen For electrically driven platen motion, see 8.3.2.2.


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8. Electric HIMMs This clause covers additional safety requirements for horizontal injection molding machines with one or more electrically driven axis and the principle of interlocking equivalent to Type I, II and III described in 7.3.

8.1 Emergency Stop Emergency stop shall conform to 7.2.4.4.

For Category 0 emergency stop that results in uncontrolled stopping of electrically driven axes, the access time to the hazardous area shall be:

(a) Greater than the stopping time. or (b) Prevented by guard locking device until

standstill has been detected (see 8.2.1).

8.2 Guard Locking

8.2.1 Access Time

Access time t to the protected area must be greater than stopping time T of the moving part. t = d/v + Δt where t = access time d = distance between the guard and dangerous point v = approach velocity which is 1.6 meters/second (63 inches/second) Δt = 100 milliseconds to take into account the time of opening the guard.

E8.2.1 Access Time Example: A guard is at 12 inches from the hazardous motion and the motor stopping time is 160 millisecond. The calculation of the access time is as follows: d = 12 inches t = 12/63 + 100 = 190 + 100 = 290 millisecond In this example, the calculated access time of 290 milliseconds is greater than the motor’s 160-millisecond stopping time.

8.2.2 Locking Device Locking device components according to category 1 shall be used. The components shall be designed to withstand a minimum force of 1000 Newton (225 pounds-force) when trying to open the guard when the guard locking is engaged.

E8.2.2 Locking Device See 3.23.

8.3 Electrically Driven Axis of the Platen Movement

8.3.1 Safe Standstill when Mold Area Guard Is Open – Prevention of Unexpected Startup

The safe standstill when mold area guard is open shall be achieved by interrupting the energy supply to the movement of the platen by two channels according to Figure 11 or Figure 12 or Figure 13. The interruption of both channels shall

E8.3.1 Safe Standstill when Mold Area Guard Is Open – Prevention of Unexpected Startup See clause C1 of annex C for the explanation of standstill and safe standstill.


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be independent from the programmable controller. The following shall be used:

Contactors in the power supply to the electrical motor or the motor control unit;

and/or

Safety-related input(s) to motor control unit. Safety circuit shall comply with 7.2.4.1. 8.3.2.1 Operator Gate Access to the mold area shall be prevented by interlocking guards with guard locking device. Guard locking shall remain effective until unit standstill condition has been detected (see Annex C).

E8.3.2.1 Operator Gate See 8.2.2, Locking device.

8.3.2.2 Rear Guard, Top Guard, and Clamping Mechanism Area Where access to the platen and its drive mechanism is prevented by movable guards (see 7.3.1.6, 7.3.1.7 and 7.3.2), these shall be interlocking guards in accordance with Figure 16 or Figure 17.

In case of dangerous coasting, i.e., access time t is less than T (overall stopping time) as defined in 8.2.1, the guard for these areas shall be an interlocking guard with guard locking device.

8.3.3 Requirements for the Monitoring Circuit The following shall be automatically monitored at least once during each cycle of the movable guard:

• The change of state of the position detectors of the guard (not applicable to Figure 14 and Figure 15 if S1 is a well-tried component)

• The position of the contactors or the information given by the motor control unit.

• The position of the lock, if applicable. • The information given by the standstill

detection, if applicable. If a single fault occurs, the automatic monitoring shall prevent the initiation of any further movement. Safety circuit monitoring shall comply with 7.2.4.1.


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8.4 Electrically Driven Axis for the Movement of

the Plasticizing and/or Injection Unit For this movement, the interlocking of the guard for the nozzle area shall be according to Figure 14 or Figure 15 and the interlocking of the guard for the mold area shall be in accordance with Figure 16 or Figure 17. In case of dangerous coasting, where access time t is less than T (overall stopping time) as defined in 8.2.1, the guard for the nozzle area shall be an interlocking guard with guard locking device.

8.5 Electrically Driven Axis for the Rotation of the Plasticizing Screw This movement, the interlocking of the guard for the nozzle area shall be according to Figure 14 or Figure 15 and the interlocking of the guard for the mold area shall be in accordance with Figure 16 or Figure 17.

8.6 Electrically Driven Axis for the Linear Movement of Screw or Plunger For this movement, the interlocking of the guard for the nozzle area shall be according to Figure 14 or Figure 15 and the interlocking of the guard for the mold area shall be in accordance with Figure 16 or Figure 17. Guard locking is not required because the coasting is not dangerous.

8.7 Electrically Driven Axis for Cores and Ejectors For the movement of cores and ejectors, the interlocking of the guards outside the mold area shall be according to Figure 14 or Figure 15 and the interlocking of the guard for the mold area shall be in accordance with Figure 16 or Figure 17. In case of coasting, i.e., access time t less than T (overall stopping time), the guards outside the mold area shall be interlocking guards with guard locking device. In case of interlocking guards without guard locking outside the mold area, the access time shall be calculated as in 8.2.1. The guard for the mold area shall remain locked until the cores and ejectors movement stops.


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8.8 Stopping Performance The manufacturer shall specify in the equipment instructions the maximum stopping distance or time of the parts driven by electrical axis for which there is interlock without guard locking.

8.9 Electrical or Electromagnetic Disturbance In order to reduce electrical and electromagnetic disturbance, the motor control units shall be installed in accordance with the motor control manufacturer’s recommendation for grounding, shielding and filtering.

E8.9 Electrical or Electromagnetic Disturbance

As an example, the proper grounding using braided conductors reduces the high-frequency electrical noise. The use of electrical reactor and filter reduces the conducted and radiated electrical noise.


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Key K1, K2 Contactors S1, S2, S3 Position detectors L Guard locking Device 1 Electrical motor 2 Motor control unit according to category B 3.1 Guard closed 3.2 Guard open 4 Control circuit of the machine 5 Monitoring circuit of the machine 6 Standstill detection One of the position detectors (Limit Switch) may be used to achieve guard locking. K1 and K2 shall be positioned between the motor and the motor control unit if there is the possibility of hazardous movements due to stored energy in the motor control unit. In other cases, K1 and K2 shall be positioned on opposite sides of the motor control unit to prevent common mode failure. Monitoring the position detector S1 is not required if the change of the state is automatically monitored by position switching of the contactor K2.

Figure 11 – Principle of Interlocking Corresponding to Type III using Motor Control Unit according to Category B


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Key K1 Contactor S1, S2, S3 Position detectors L Guard locking Device 1 Electrical motor 2 Motor control unit according to category other than B for safe standstill 2.0 Confirmation of switch off condition from 2.1 2.1 Safety related input 3.1 Guard closed 3.2 Guard open 4 Control circuit of the machine 5 Monitoring circuit of the machine 6 Standstill detection One of the position detectors (limit switch) may be used to achieve guard locking. K1 shall be positioned between the motor and the motor control unit if there is possibility of hazardous movements due to stored energy in the motor control unit. In other cases, K1 may be positioned on the other side of the motor control unit. Figure 12 – Principle of Interlocking Corresponding to Type III using Motor Control Unit according

to Category Other than B for Safe Standstill


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Key S1, S2, S3 Position detectors L Guard locking Device 1 Electrical motor 2 Motor control unit according to category B for safe standstill 2.0 Confirmation of switch off condition from 2.1 2.1, 2.2 Safety related inputs 2.3 Confirmation of switch off condition from 2.2 3.1 Guard closed 3.2 Guard open 4 Control circuit of the machine 5 Monitoring circuit of the machine 6 Standstill detection

One of the position detectors (limit switches) may be used to achieve guard locking. If monitoring of the safety related inputs is achieved within the motor control unit, one return line to the monitoring circuit of the machine is sufficient. Figure 13 – Principle of Interlocking Corresponding to Type III using Motor Control Unit according

to Category B for Safe Standstill


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Key K1 Contactor S1 Position detector L Guard locking Device (if dangerous coasting can occur) 1 Electrical motor 2 Motor control unit according to category B 3.1 Guard closed 3.2 Guard open 4 Control circuit of the machine 5 Monitoring circuit of the machine 6 Standstill detection The position detector (limit switch) may be used to achieve guard locking. K1 shall be positioned between the motor and the motor control unit, if there is a possibility of hazardous movements due to stored energy in the motor control unit. In other cases, K1 may be positioned on the other side of the motor control unit. If there is no guard locking, the lines with dots and dashes are deleted.

Figure 14 – Principle of Interlocking Corresponding to Type I using Motor Control Unit according to Category B


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Key S1 Position detector L Guard locking Device (if dangerous coasting can occur) 1 Electrical motor 2 Motor control unit according to category other than B for safe standstill 2.0 Confirmation of switch off condition from 2.1 2.1 Safety related input 3.1 Guard closed 3.2 Guard open 4 Control circuit of the machine 5 Monitoring circuit of the machine 6 Standstill detection The position detector (limit switch) may be used to achieve guard locking. If there is no guard locking, the lines with dots and dashes are deleted.

Figure 15 – Principle of Interlocking Corresponding to Type I using the Motor Control Unit according to Category other than B for Safe Standstill


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Key K1 Contactor S1, S2 Position detectors L Guard locking Device (if dangerous coasting can occur) 1 Electrical motor 2 Motor control unit according to category B 3.1 Guard closed 3.2 Guard open 4 Control circuit of the machine 5 Monitoring circuit of the machine 6 Standstill detection One of the position detectors (limit switch) may be used to achieve guard locking. K1 shall be positioned between the motor and the motor control unit, if there is a possibility of hazardous movements due to stored energy in the motor control unit. In other cases, K1 may be positioned on the other side of the motor control unit. If there is no guard locking, the lines with dots and dashes are deleted.

Figure 16 – Principle of Interlocking Corresponding to Type II using Motor Control unit according to Category B


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Key S1, S2 Position detectors L Guard locking Device (if dangerous coasting can occur) 1 Electrical motor 2 Motor control unit according to category other than B for safe standstill 2.0 Confirmation of switch off condition from 2.1 2.1 Safety related input 3.1 Guard closed 3.2 Guard open 4 Control circuit of the machine 5 Monitoring circuit of the machine 6 Standstill detection One of the position detectors may be used to achieve guard locking. If there is no guard locking, the lines with dots and dashes are deleted.

Figure 17 – Principle of Interlocking Corresponding to Type II using the Motor Control Unit according to Category other than B for Safe Standstill


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9 Existing HIMMs An existing HIMM is any HIMM that is manufactured prior to the compliance date of this standard. Compliance date is one year after the publication date of this standard.

9.1 Employer Responsibility The employer shall ensure that all HIMMs are in conformance with clauses 9 and 11 of this standard.

E9.1 Employer Responsibility The 1997 version of this standard listed safety requirements for existing HIMMs. However, HIMMs built to the new machine requirements of the 1997 standard are now also existing machines. These HIMMs have some additional features that must be maintained in proper working order. These additional features are designated in this clause by underlining.

9.2 Mold Area Guarding

9.2.1 Operator's Gate(s) An operator's gate shall be provided as a barrier to keep personnel away from moving parts, the mold, and splattering of hot melt while the HIMM is operating. The operator's gate shall be closed before the HIMM can be operated. Interlocks shall be provided in accordance with 9.2.2, 9.2.3, and 9.2.4 of this standard. When an opening movement of the movable platen is possible with the operator’s gate open, access to pinching and shearing points behind the mold mounting surface of the movable platen shall be prevented.

E9.2.1 Operator's Gate(s) The HIMM may have more than one operator’s gate.

9.2.1.1 Power-Operated Gate If a power-operated gate is used, the exposed leading edge(s) shall incorporate a pressure-sensitive switch or equivalent device such that if the switch is activated the gate motion stops or reverses. The pressure-sensitive switch shall be designed into the circuit such that a failure of the switch duplicates actuation of the switch. The power assist mechanism shall not lessen the effectiveness of the operator's gate. Closure of a power-operated gate shall not directly initiate a HIMM cycle.


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Exception: Where a robot is used, HIMM cycle may be initiated by a robot position signal. 9.2.2 Electrical lnterlock A hardwired electrical interlock shall be provided that will prevent the following motions when the operator's gate is opened sufficiently to permit access to the mold area: 1) platen closing 2) injection forward 3) screw rotation 4) core 5) ejector If the HIMM was manufactured or remanufactured with the operator’s gate interlocked with core and ejector motion, the functionality of this interlocking shall be maintained. The interlock shall be so located or protected to prevent accidental actuation. When a HIMM is powered by sources other than hydraulics or pneumatics, an additional independent interlock shall be provided. Exception: When the mechanical device is a jam bar (which is effective only in the platen adjusted open position), the electrical interlock shall allow platen open motion to continue to its adjusted open position so that the mechanical device engages.

E9.2.2 Electrical Interlock See 9.2.9 for exception regarding screw rotation.

9.2.3 Mechanical Device A mechanical device shall be provided such that when the operator's gate is opened sufficiently to permit access to the mold area, the platen will be physically prevented from closing when the platen is in its adjusted open position. If the mechanical device is a jam bar, see 9.2.2 for exception. If the HIMM was manufactured or remanufactured with a ratchet type mechanical device, the platen shall be physically prevented from closing when the operator's gate is opened sufficiently to permit access to the mold area. If the HIMM was manufactured or remanufactured after July 22, 1998, a monitoring device shall be provided to check the operation of the mechanical device. If improper operation is detected, the HIMM cycle shall be inhibited and an alarm shall be activated.

E9.2.3 Mechanical Device The intent of this device is to provide a physical obstruction to impending closing motion of the moving platen. Some platen closing motion may occur before the mechanical device is fully engaged. The mechanical device is not intended to resist clamp-up force. The mechanical device may include a ratchet bar or a friction-type device.


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9.2.4 Hydraulic or Pneumatic Interlock If hydraulic or pneumatic power is used to cause platen motion, then a hydraulic or pneumatic interlock shall be provided such that the platen close circuit shall be interrupted unless the operator's gate is closed sufficiently to exclude the operator from hazards. This hydraulic or pneumatic interlock shall be actuated by mechanical or electrical means which are independent of all other interlocks. If the hydraulic or pneumatic interlock is actuated by electrical means, a monitoring device shall be provided to verify the operation of this hydraulic or pneumatic interlock. If improper operation is detected, the HIMM cycle shall be inhibited and an alarm shall be activated. If the HIMM was manufactured or remanufactured with a monitored hydraulic interlock actuated by other than electrical means, the interlock shall be functional and when improper operation is detected, the HIMM cycle shall be inhibited and an alarm shall be activated.

9.2.5 Motion/No Motion Option for Platen, Core, and Ejector The selection between motion and no motion shall be accomplished by the use of a lockable switch and shall only be effective in semi-automatic mode. When no motion is selected, all platen, core, and ejector motion shall be inhibited with the operator’s gate open. When motion is selected, platen open, ejector forward, and core out motion shall be permitted with the operator’s gate open. No platen, core, or ejector motion shall be permitted in automatic or manual mode with the operator’s gate open. When an opening movement of the movable platen is possible with the operator’s gate open, access to shearing and pinching points behind the mold mounting surface of the movable platen shall be prevented.

E9.2.5 Motion/No Motion Option for Platen, Core, and Ejector It is recognized that some special molds require that the part be manually lifted from the mold, in single or semi-automatic cycle. See 10.9.


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9.2.6 Rear Guard For HIMMs manufactured or remanufactured prior to January 2, 1991, the mold area opposite the operator of the HIMM shall have a rear guard with at least one interlock to prevent all machine movement if the guard is open or removed. For HIMMs manufactured or remanufactured after January 2, 1991, the mold area opposite the operator of the HIMM shall have a rear guard with two interlocks that separately interrupt the control circuit and the power circuit to prevent all HIMM movements if the guard is open or removed.

E9.2.6 Rear Guard A rear guard should be so placed on the HIMM as to leave an opening between the guard and either the platens or the frame of the HIMM to allow clearance for water lines and other necessary items for connecting to the molds. The rear guard is designed to be opened and closed during setup and maintenance functions only. The rear guard may be replaced by an additional operator’s gate. See 9.2.1.

9.2.7 Top Guard A top guard shall be installed when it would be possible for a person standing on the floor to reach over the top of the operator’s gate or guard and into a hazardous area. If the top guard is movable, an interlock shall be provided that will prevent all motion of the HIMM if the top guard is open or removed. If a fixed guard is used, an interlock is not required.

E9.2.7 Top Guard The top guard can be an integral part of or mechanically attached to the operator gate or the rear guard.

9.2.8 Parts Discharge Opening The parts discharge opening (front and rear) shall be guarded to prevent access to hazards in the mold area through this opening.

E9.2.8 Parts Discharge Opening The presence of a conveyor or chute may function as a guard. (See ANSI/ASME B20.1-1990.) See 10.4. It is recommended that the dimension in Figure 9 be met using fixed or movable guards if necessary. Permanent tubing or other fixed machine member may provide some or all of this guarding requirement.

9.2.9 Nozzle Shutoff Device Screw rotation shall be allowed with the operator’s gate open only when the nozzle shutoff device prevents material discharge.

9.3 General Guarding (Other than Mold Area Guarding)

E9.3 General Guarding (other than Mold Area Guarding) Slot head fasteners are not recommended for attaching the fixed guards.

9.3.1 Guards Guards shall be provided where hazards exist. Movable guards shall be interlocked to stop hazardous motion exposed by moving or removing the guard.


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Fixed guards shall require fasteners to attach the guard in place and tools to install or remove the fasteners. 9.3.2 Feed Openings All feed openings for plastic materials shall be guarded against inadvertent insertion of hands. Safety signs shall be used in this area. See clause 11.

E9.3.2 Feed Openings A hopper can serve as a fixed guard for the feed throat opening to prevent inadvertent insertion of hands.

See clause B4 of Annex B for clearing a blocked feed throat.

9.3.3 Vent Cover A cover shall be provided over the vent port to protect personnel from hot plastic and/or vapors that may be expelled.

E9.3.3 Vent Cover See 10.6 for vapor hazards and 10.8 for personal protective equipment.

9.3.4 Electrical Systems HIMMs shall be in accordance with the requirements of ANSI/NFPA 79 where personal safety will benefit.

9.3.5 Purging Protection A guard shall be provided to protect the front, rear, and top of the purging area behind the stationary platen. The guard shall be interlocked to prevent screw rotation, screw or plunger forward, and electrically actuated injection carriage forward motion when the guard is not in position. Purging shall be prevented with the operator's gate open. If the HIMM was manufactured or remanufactured with a hydraulically operated injection carriage, forward motion interlocked with the purge guard, the functionality of this interlock shall be maintained.

9.3.6 Injection Barrel Covers A cover or barrier shall be provided to prevent inadvertent contact with high temperatures when the injection unit is in the normal operating position.

E9.3.6 Injection Barrel Covers Insulating blankets may serve as the cover or barrier to prevent inadvertent contact with high temperature.


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9.3.7 Injection Unit Swivel Interlock If the HIMM was manufactured or remanufactured with an injection unit swivel interlock, whenever the injection unit is swiveled out of the normal operating position, screw or plunger forward motion shall only be possible in manual mode. Maximum screw or plunger forward speed shall be 13 mm/sec (0.5 in/sec)

E9.3.7 Injection Unit Swivel Interlock The purpose of reduced screw or plunger forward speed is to permit screw removal/maintenance. See clause B.5 of annex B for screw removal procedure.

9.4 Additional Safety Measures for Large HIMMs

9.4.1 Area between Operator’s Gate and the Mold Area Where it is possible to stand between the operator’s gate and the mold area, an emergency stop or emergency reverse button shall be provided in a location that is readily accessible from this area. Additionally, where it is possible to stand between the operator’s gate and the mold area, one of the following devices shall be provided: a) Gate Block A mechanical device shall be provided that operates with each opening movement of the operator's gate to prevent the unintentional return of the gate to the closed position. The disengagement of this mechanical device and closure of the operator's gate shall occur only by the direct and continuous action of the operator. The position from which this device is disengaged and the operator’s gate is actuated shall allow a clear view of this area. If the HIMM was manufactured or remanufactured after July 22, 1998, a monitoring device shall be provided to check the operation of the mechanical device. If improper operation is detected, the Large HIMM cycle shall be inhibited and an alarm shall be activated. Exception: Where a floor-entry-mounted robot is used, disengagement of this device and closure of the gate may be initiated by a robot signal. or

E9.4.1 Area between Operator’s Gate and the Mold Area a) Gate Block See ANSI/SPI B151.27, American National Standard for Plastic Machinery – Robots Used with Horizontal and Vertical Clamp Injection Molding Machines


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b) Double Acknowledgment System A double acknowledgment system shall consist of a push button (#1) located inside of the operator’s gate with clear view of the mold area and a second push button (#2) located outside of the operator’s gate with a clear view of this area which cannot be actuated from inside the closed operator’s gate. The start of a cycle shall be possible only after the following sequence has been completed within a time interval prescribed by the Large HIMM manufacturer: 1) Push button #1 2) Close operator’s gate 3) Push button #2 – Cycle initiation A monitoring circuit shall be provided to check the operation of each push button. If improper operation or sequencing is detected, the Large HIMM cycle shall be inhibited and an alarm shall be activated.

or

c) Presence-sensing device A presence-sensing device that, when activated, will prevent, stop, or reverse the closure of the operator’s gate.

b) Double Acknowledgment System The power-operated gate close button can also act as the cycle initiation provided it is pushed a second time after the gate is closed.

9.4.2 Area between the Rear Guard and the Mold Area Where it is possible to stand between the rear guard and the mold area, an emergency stop or emergency reverse button shall be provided in a location that is readily accessible from this area.

E9.4.2 Area between the Rear Guard and the Mold Area Since this area of the machine is protected (see 9.2.6) by stopping all machine motion when the rear guard is opened to gain access, no additional safety measures shall be required.

9.4.3 Mold Area Protection

9.4.3.1 Mold Area with Working Platform When the large HIMM is supplied with a working platform in the mold area for the purpose of operator access during normal production, one or more presence-sensing device(s), such as a safety mat, an interlocked platform, a photo-electric beam, or other similar device, shall be provided and positioned such that a person standing on the platform would activate the device(s). Actuation of the presence-sensing device(s) shall prevent the initiation of platen motion, powered operator's gate closing motion, core and/or ejector motion, and injection motion.

E9.4.3.1 Mold Area with Working Platform The surfaces of the tiebars are not acceptable standing surfaces and should not be considered a part of the working platform. A working platform is an indication of the expectation of whole body entry of the operator into the mold area during normal production.


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Actuation of the presence-sensing device(s) during platen closing shall stop all motion and require the manual resetting of the large HIMM before a new cycle may be initiated. Platen open, ejector forward, and core out motion may be permitted when the presence-sensing device is actuated if this motion does not in itself create a hazard. 9.4.3.2 Mold Area without Working Platform When the large HIMM is not supplied with a working platform in the mold area for the purpose of operator access during normal production, one of the following devices shall be provided: a) Gate Block A mechanical device as described in 9.4.1(a). The position from which this device is disengaged and the operator’s gate is actuated shall allow a clear view of the mold area. or b) Double Acknowledgment System A double acknowledgment system as described in 9.4.1(b)

9.4.4 Cycle Initiation Closure of the operator’s gate shall not directly initiate large HIMM motion. Closure of the operator's gate shall require direct and continuous action by the operator.

9.5 Emergency Stop Button Each operator’s control station shall include one emergency stop button.

9.6 Window When a window is used in a gate or guard to provide visibility, the window material shall conform to ANSI Z97.1.

9.7 Safety Signs All new signs and any replacements of old signs shall be designed and constructed in accordance with clause 11 of this standard.


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10 Use

10.1 Training of Operators, Setup and Supervisory Personnel

The employer shall train and instruct personnel in the safe method of operation of the safety devices and procedures as described in clauses 7, 8, 9, 10, and 11, before starting work on any operation covered in this standard. The employer shall ensure by adequate supervision that correct operating procedures are being followed.

E10.1 Training of Operators, and Setup and Supervisory Personnel The employer should consider setting up a checklist to ensure that operators are kept aware of procedures to follow in operating the HIMM safely. This checklist should be kept in the HIMM instructions, and periodically (such as every 6 months), the employer should have operators check off this list.

10.2 Work Area

The employer shall provide clearance between HIM’s so that movement of one operator will not interfere with the work of another. Ample room for cleaning of HIMMs and handling of material, workplaces, and scrap shall also be provided. All surrounding floors shall be kept in good condition, clean, and so far as possible, in a dry condition.

If an external working platform is provided by the employer, reach over safety distances shall be maintained in accordance with 7.1.

E10.2 Work Area

The handling of raw materials, parts in process, finished parts, scrap, and waste is a part of every plastics plant operation. Proper materials handling is important for the safety and performance of HIMMs and HIMM operators.

10.3 Set Point Users shall consult the material manufacturer for the material being processed and set the injection barrel maximum and minimum temperature accordingly to prevent hazardous conditions.

10.4 Parts Discharge Area When conveyors or other parts removal devices require modification of parts discharge opening guarding, the employer shall be responsible for preventing access to hazards in the mold area with additional guarding and/or stopping HIMM motion through presence-sensing devices and/or interlocked guards. Whenever such guarding would render the conveyor or chute unusable, prominent warning means shall be provided by the employer in lieu of such guarding.

E10.4 Parts Discharge Area Because of the wide variety of ancillary equipment such as conveyors, chutes, robots, and the like, it is impossible for the HIMM manufacturer to effectively guard the parts discharge area in anticipation of employer modification. See 9.2.8.

10.5 Vent Port Conversion Some vented injection barrels are designed only to operate with vent port open. Others may be designed to operate either in the open vent port mode or with a mechanical plug in the vent port. Always consult and follow the vented barrel manufacturer’s instructions.


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10.6 Ventilation A means shall be provided by the employer to vent hazardous vapors away from the work area.

10.7 Ancillary Equipment It shall be the responsibility of the employer to ensure that the use of ancillary equipment for handling or access at HIMM’s, for example, conveyors, lifts, take-off devices, robots, and the like, shall not reduce the level of safety embodied in this standard.

E10.7 Ancillary Equipment See 10.4.

10.8 Personal Protective Equipment Personnel shall wear appropriate personal protective equipment for protection against setup and maintenance hazards associated with a HIMM. Operators shall be required to wear production specific personal protective equipment.

E10.8 Personal Protective Equipment Insufficient pre-drying or degradation of certain plastic materials may cause unintentional discharge from the nozzle or mold. See Annex B for examples of typical set-up and maintenance tasks requiring personal protective equipment.

10.9 Mold Guarding On HIMM’s fitted with a lockable switch as defined in 7.3.1.8 and 9.2.5, it shall be the responsibility of the employer to authorize the selectable position of this lockable switch, only after the employer has assured that pinching and shearing points created by these movements are guarded. Accessible shearing and pinching points within the mold shall be guarded by the employer. For motion/no motion operation, ejector forward and core out motion must be guarded.

10.10 Interrupted Cycle If for any reason, the cycle on the HIMM is interrupted for an extended period of time, it shall be the responsibility of the employer to assure that proper shut down procedures are followed.

E10.10 Interrupted Cycle Proper shut down procedures are dependent upon the type of material being processed. Refer to the Material Safety Data Sheet from the material supplier or to the material supplier’s recommendations.

10.11 Automated Mold Change When clamp motion is required during automated mold changing, interlocked guarding shall be used that does not reduce the level of safety.

10.12 Nozzle Modification If the nozzle configuration is modified the user shall ensure that the requirements of 7.3.3 and 9.3.5 are met.

E10.12 Nozzle Maintenance See Annex B for operating procedures


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10.13 Hose Inspection Evaluate factors such as the nature and severity of the application, past history and manufacturers information to establish the frequency of visual inspections and functional tests. Inspect all hoses for:

• Leaks at hose fitting or in hose • Damaged, cut or abraded cover • Exposed reinforcement • Kinked, crushed, flattened or twisted hose • Hard, stiff heat cracked or charred hose • Blistered, soft, degraded or loose cover • Cracked, damaged or badly corroded

fitting • Fitting slippage on hose • Other signs of significant deterioration

If any of the above conditions exist, the hose assembly shall be replaced with a new assembly of equivalent quality and characteristics.

E10.13 Hose Inspection It is recommended that all hoses are inspected monthly.

See SAE J1273.

11 Safety Signs All signs shall conform to ANSI Z535.3-2002 and ANSI Z535.4-2002 in color, format, size, and content.

E11 Safety Signs Existing signs need not be replaced unless they are unreadable,


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ANNEX A (informative) This annex is not normative due to the rapidly changing state of the art. Use of proportional valves for the platen movement When using proportional valves to control the platen movement the following should be taken into account: A.1 Design A.1.1 In case of an energy failure, proportional valves should return to the basic position by means of springs. A.1.2 In its basic position, the pressure connection side of the proportional valves should either be blocked or exhausted to tank. A.1.3 No leakage which could cause a dangerous movement should be present when the proportional valves are in their basic positions. This could be achieved, e.g., by close tolerance valves or exhausting leakage from the proportional valves directly to tank. A.2 Mode of operation A.2.1 The basic position of the proportional valves should be achieved at least once during each cycle A.2.2 The proportional valves which control the platen movement should not be used for controlling any other movement. A.2.3 When the movable guards of the mold area are open the position switches should:

- directly interrupt the energy supply to the solenoid of the proportional valve responsible for the closing movement of the platen or - directly switch off the energy supply to the control card of the proportional valve. In this case it should be ensured that any residual value existing in the control card cannot give rise to a closing movement of the platen.

A.2.4 Alternatives to A.2.3 that may be used are, e.g.:

- an additional valve (not proportional) to interrupt the control oil to the proportional valve; or - an additional valve (not proportional) to position the proportional valve in its basic position; or - an additional valve (not proportional) which inhibits platen closing movement.

In all these cases, the energy supply to the solenoid of the additional valve should be directly interrupted by the position switches of the movable guards for the mold area when these guards are opened. A fault of the additional valve should not affect the safety function of the proportional valve and should be automatically detected by the control system; otherwise the additional valve should be automatically monitored using the principle described in 7.2.4.1.


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ANNEX B (informative) - SPI RECOMMENDED PROCEDURES

B.1 – Lockout/Tagout Procdure

1. Read and understand this entire procedure before beginning.

WARNING:

Failure to perform the Lockout/Tagout procedure before commencing with maintenance activities can lead to serious injury or death.

A “positive, lockable” means to remove all energy sources prior to maintenance must be provided. It is the employer’s responsibility to provide a lockout/tagout procedure for each machine that is in compliance with all applicable national and local requirements. The following procedure is a general guide:

2. Turn off all motors.

3. Turn off and lock the electrical disconnect switch(s) and all other energy sources. Place a tag on the switch to indicate that work is being performed on the machine.

4. Verify that all auxiliary equipment with separate power sources has been turned off. Lock and tag each disconnect switch in the OFF position.

5. Verify that electrical power has been disconnected from the machine and from any auxiliary equipment. If the machine or any piece of equipment is energized, locate the electrical circuit(s) supplying the power. Disconnect all power sources and lock and tag these power sources in the OFF position.

6. Verify that no sources of residual energy (accumulators, capacitors, suspended machine components, etc.) are present on any equipment. If necessary, manually discharge hydraulic, pneumatic, or steam pressure and capacitor voltage from charged components. Also, block all suspended or spring-loaded machine parts to prevent movement.

7. Perform required maintenance

8. When work is completed on the machine, visually inspect that all safety devices are in place.

9. Notify other affected employees that the locks and tags are being removed, and verify that all tools and personnel are clear of the machine.

10. When the machine is ready to resume operation, each individual shall remove their own lock(s) and tag(s).

If a personal lock or tag is left on an isolation point after all work has been completed, every attempt must be made by the supervisor responsible to contact the person or persons whose name appears on the tag.

a. Contact the individual who performed the lockout/tagout instructions. Ask this individual to remove the lock and/or tag. If the person cannot return to the site they may give verbal permission to remove the lock or tag along with any specific instructions that may be required to return the machine to a safe operating condition.

b. Verify the danger zone is clear of all personnel before attempting to remove the lock or tag.

c. If the person or persons cannot be contacted to remove the lock or tag, conduct a joint investigation involving the supervisor responsible for the area (or machine) and a competent technician who has a thorough understanding of the process and the machine:

i. Check all isolation points to make sure lines, wires, and/or systems are set to a safe position or condition.

ii. Verify the danger zone around the machine is clear of personnel.


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iii. When both the supervisor and the technician agree that all systems are in order and there is no potential for injury, remove the lock and/or tag.

11. If no other locks or tags remain on the machine, restart the machine using the startup procedures. 12. Before operating the machine, perform a full safety check. Personnel can be seriously injured if the machine is operated with non-functioning safety devices. Lockout/Tagout Service Provision Some service operations must be performed with the power on. The temporary removal of locks or tags from the machine is permitted ONLY under special testing or positioning conditions: for example, when power is needed to test or troubleshoot the machine, equipment, or components. Conduct machine startup and operation in accordance with the sequence of steps listed below: 1. Clear the machine or equipment of tools and materials.

2. Clear all employees from the machine or equipment area.

3. Remove only the lockout or tagout devices necessary to operate the machine or equipment for testing.

4. Power up the machine or equipment only as necessary to perform the operation or to proceed with testing or positioning.

5. After completing the procedure, de-energize all systems, isolate the machine or equipment from the energy source, and reapply the lockout or tagout devices removed in step 3.

Alternative Method for the Plastics Industry

Set-up with no motion: On plastics molding machines where it is necessary to maintain heat to a plasticizing unit or power to the programmable logic controller or microprocessor during set-up only, a user shall do one of the following: Provide and use a separate lockable energy isolating device for a motor, pump, or any other equipment that could expose an employee to a hazard; For a plastics molding machine that is in compliance with the current, applicable safety standards, the controlling safety gate shall be locked in the open position with the power source(s) used for controlling motion/movement in the mold area turned off. Where accumulators are used, they shall automatically dump pressure to tank when the hydraulic pump motor(s) is de-energized. Effects of gravity: When dangerous movement(s) in the mold area can be produced by the effect of gravity, a mechanical restraint device shall be used.


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B.2 – Clearing a Blocked Injection Barrel Nozzle or Tip

WARNING:

If the nozzle appears to be blocked, never, under any circumstances, attempt to remove the blockage without first backing off the screw to its fully retracted position to decompress the nozzle area. Never attempt to clear the blockage by using heat or pressure. The elevated temperatures in the barrel can generate explosive pressures against a blocked nozzle, which can release violently and unexpectedly. Failure to follow these instructions can result in serious personal injury and/or death.

1. Read and understand the entire procedure before beginning. 2. If the nozzle appears to be blocked, use the following procedure to cautiously remove the blockage.

Consult the Material Safety Data Sheet from the material supplier for any special material properties that might affect this procedure.

3. Retract the nozzle from the sprue bushing ensuring that nozzle remains shielded by the purge guard. 4. In some cases removing the nozzle from the heat sink of the mold sprue will clear the blockage in a

short period of time (1-2 minutes) 5. If the nozzle remains blocked, move the screw back to its fully retracted position, and leave it in the

retracted position. 6. Stop the motion. 7. Check the correct functions of the nozzle heating system. Lock-out and tag-out and repair as required

and return to Step 4. 8. Turn off the barrel heats. 9. Lock-out and tag-out the machine. Refer to your specific plant procedure and any special

requirements in your machine manual. 10. Wear approved protective equipment/clothing - this includes safety glasses and full face shield and full

body protection to protect against pressurized plastic gas and hot plastic which could expel from the barrel. Clear area of all personnel except person about to unscrew barrel nozzle.

11. Open the purge guard. 12. Disconnect and remove the nozzle heaters (where applicable). 13. Do not stand in front of the nozzle. To avoid contact with any unexpected release of plastic pressure,

slowly unscrew the nozzle and clear the blockage.


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B.3 – Blocked Injection Barrel Vent

WARNING:

If steam and/or plastic vapor is not coming from the barrel vent, the barrel vent may be blocked. If this occurs, there will be trapped gas behind the blockage. Failure to follow the instructions in this section may result in serious personal injury.

1. Read and understand the entire procedure before beginning. 2. Consult the Material Safety Data Sheet from the material supplier for any special material

properties that might affect the procedure.

3. If the barrel vent is equipped with a heater band, check the temperature of the heater band. If the temperature is not correct, the heater band may need to be replaced. Use the following procedure when replacing the barrel vent heater band with the vent blocked. a. Wear protective equipment/clothing - this includes safety glasses, full face shield,

insulated gloves, and full body protection to protect against pressurized gas and plastic which could be expelled from the vent.

b. Completely purge the injection barrel as indicated in the purging instructions. Leave the screw in its fully retracted position. c. Follow the lockout/tagout procedure. d. Allow the barrel to cool to room temperature to protect against the possibility of being

burned by hot plastic and/or hot gas, which could be expelled from the vent. e. Repair or replace the heater band. f. Turn the main disconnect and barrel heaters on and allow the barrel to reach operating

temperature. g. Check the barrel vent for flowing plastic or gas.

4. If the heater band is at the proper temperature but the vent still appears to be blocked, use the following procedure to clear the blockage. a. Follow Steps 2(a) through 2(d) above. b. Carefully remove the vent cover and clear the blockage from the vent.

c. Re-install the vent cover. 5. If the blocked vent barrel problem persists, contact the vented barrel and screw supplier.


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B.4 – Clearing a Blocked Feed Throat

WARNING:

Hot plastic melt and/or gasses may be trapped just below the bridged material. Sudden release of hot plastic or gas can cause serious injury or death. Follow instructions below to avoid injury.

1. Read and understand this entire procedure before beginning. 2. Shut off the feed hopper slide or gate to stop the flow of plastic pellets (or powder) from the hopper

into the feed throat. 3. Retract the injection unit to separate the nozzle from the mold. 4. Purge out the plasticizer completely to reduce the potential for trapped gasses and/or decomposed

material splattering hot plastic. 5. Lockout/Tagout all power to the motor(s) and heaters. 6. Make certain that the feed throat cooling is operating. Check the temperature of the feed throat jacket.

If overheated, do not remove (or swing away) the hopper until the barrel and feed throat temperature has reached less than 100 °F (37°C) in both the feed housing and barrel.

7. Wear appropriate personal protective equipment such as long protective gloves, full body protective

clothing and face shield. 8. Hot plastic melt and/or gasses may be trapped just below the bridged material. Carefully remove the hopper. Use a vacuum to remove unmelted plastic. Never place your fingers or hand into this opening. Use tongs or other brass tools to remove material from this opening. 9. Then using a brass rod or flat brass chisel and hammer, carefully break up the plastic bridge into chunks and vacuum the same away from the feed hole. 10. If these efforts fail, then remove the nozzle, barrel head and screw from the unit to facilitate removal of the bridge per procedure.


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B.5 – Screw Removal

WARNING:

While removing the screw, there is a danger of hot plastic being expelled and causing burns. Make sure the injection area is clear of personnel and wear protective equipment to guard against burns.

1. Read and understand this entire procedure before beginning. 2. Stop the flow of resin. 3. Purge the machine. Refer to purging instructions.

a) Purge machine in accordance with instructions in purging section.

WARNING: While purging plastic, there is a danger of hot plastic spraying from the nozzle and causing burns. Make sure the injection area is clear of personnel and wear protective equipment.

b) To make sure all the plastic material has emptied, continue to purge until the screw stops recovering. Advance the screw so it is in the fully forward position toward the mold cavity.

c) Open the shut-off nozzle (if present). This will allow gaseous plastic to vent out of the open nozzle.

4. Fully retract the carriage.

5. For pivoting extruders, remove all equipment that may interfere with the extruder section when it pivots (i.e., walkway).

6. Lockout/Tagout all power to motors and heaters. See Lockout/Tagout service provision Annex B.1.

7. Uncouple the screw from the drive shaft. Refer to OEM Instructions.

WARNING: The Barrel is hot. To avoid burn injury while guiding the barrel, make sure personnel are wearing protective insulated gloves.

WARNING: Use lifting accessories that will withstand the high heat of the barrel. Failure to

do so may cause the barrel to become unbalanced and fall. This may cause serious injury to personnel.

8. Support the nozzle end of the barrel by securing lift eyes to the barrel lifting points and rigging chains to the lifting apparatus.

9. Pivot the barrel as per OEM instructions.

10. Remove barrel end cap heaters and barrel end cap retaining socket head cap screws. Always “break” the barrel end cap screws loose in a “star” pattern, not in a “round the clock” pattern. Loosen the cap screws several turns and support the end cap with a sling hoist. Remove end cap.

11. Rig lifting equipment with a chain-linked sling to the end of the screw which is protruding from the barrel. 12. Pull half of the screw out of the barrel. Make sure enough of the screw is extracted so that the lifting equipment can be installed at the screw’s midpoint. 13. Support the screw at the midpoint using lifting equipment and a chain-linked sling. If necessary, replace the lifting equipment at the end of the screw with a wood support and move the lifting equipment to the midpoint. Refer to OEM instructions.


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B.6 – Purging

WARNING:

While purging plastic, there is a danger of hot plastic spraying from the nozzle and causing burns. Make sure the injection area is clear of personnel and wear protective equipment to guard against burns. If you suspect a blocked nozzle, refer to the procedure for clearing blocked nozzle.

Procedure 1. Read and Understand the entire procedure before beginning 2. Wear personal protective equipment including safety glasses, a face shield, protective clothing and

insulated gloves with suitable hand and arm protection to guard against burns. Make sure all personnel are clear of the injection area in case hot plastic is expelled while purging.

3. Select manual/setup mode to purge. 4. Maintain normal machine heat settings suitable for the resin in use. 5. Clear purging with appropriate tools.


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Core and Ejector

(8.7)

Motor Control Drive Category

Operator Gate

Rear Guard/ Clamping

Mechanism (see note)

With Purge Guard

With Mold Area

With Purge Guard

With Mold Area

With Purge Guard

With Mold Area

With Mold Area

Category B III-Figure 11 II-Figure 16 I-Figure 14 II-Figure 16 I-Figure 45 II-Figure 16 I-Figure 14 II-Figure 16 II-Figure 16

Category other than B for safe standstill

III-Figure 12 II-Figure 17 I-Figure 15 II-Figure 17 I-Figure 15 II-Figure 17 I-Figure 15 II-Figure 17 II-Figure 17

Category 3 for safe standstill

III-Figure 13

Note:

C.2- Summary of Interlock Type and illustration (type-illustration) for electrically driven axis

Type II interlock can be used for the rear guard and clamping mechanism only if access time to dangerous motion is less than the movement stopping time, otherwise it is type III

Injection Unit Movement (8.4)

Screw Rotation (8.5)Injection Forward

Clause (8.6)Platen Movement (8.3)

ANNEX C (informative) – STANDSTILL, SAFE STANDSTILL, INTERLOCK SUMMARY AND CATEGORY OF MOTOR CONTROL UNIT FOR ELECTRICAL IMMs

C.1 –Flow chart leading to standstill and safe standstill as defined in 3.59 and 3.49

Platen moving

Request for platen to stop/guard to unlock

Stopping

Release of guard locking

Detection that the platen has stopped (by 6) STANDSTILL

Guard locking released

Opening of the guard

Change of state of the position detectors of the guard (S1, S2, S3)

Interruption of the energy supply (motor control unit, K1, K2)

Automatic monitoring (motor control unit, K1, K2, S1, S2, S3 and L)

SAFE STANDSTILL

1

2

3

4

5


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C.3 - Motor Control Unit Categories

Category Requirement Behavior

B Safety-related parts of control systems and/or their protective equipment, as well as their components, shall be designed, constructed, selected, assembled and combined in accordance with relevant standards so that they can withstand the expected influence.

The occurrence of fault can lead to the loss of the safety function.

1 Requirement of B shall apply. Well-tried components and well-tried safety principles shall be used.

The occurrence of a fault can lead to the loss of safety function but the probability of occurrence is lower than category B.

2 Requirement of B shall apply and the use of well-tried safety principles shall apply. Safety function shall be checked at suitable intervals by the machine control system.

• The occurrence of a fault can lead to the loss of safety function between the checks.

• The loss of safety function is detected by the check.

3 • A single fault in any of these parts does not lead to the loss of the safety function; and

• Whenever reasonably practicable the single fault is detected.

• When the single fault occurs, the safety function is always performed.

• Some but not all faults will be detected. • Accumulation of undetected faults can

lead to the loss of safety function. 4 • A single fault in any of these parts does

not lead to the loss of the safety function; and

• The single fault is detected at or before the next demand upon the safety function. If this is not possible, then an accumulation of faults shall not lead to a loss of the safety function.

• When the single fault occurs, the safety function is always performed.

• The faults will be detected in time to prevent the loss of safety function.

ansi guideline for injection molding

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