static charge solutions presentation by: electro static technology

Static Charge Static Charge SolutionsSolutions

Presentation by: Electro Static Presentation by: Electro Static TechnologyTechnology

Copyright © 2002 Electro Static Technology

IntroductionIntroduction

Electrostatic charges can create Electrostatic charges can create problems in equipment which problems in equipment which transport paper or other non-transport paper or other non-conductive media. conductive media.

This presentation will cover the basics This presentation will cover the basics of static charge generation.of static charge generation.

Cost effective solutions to reduce Cost effective solutions to reduce static charges to acceptable levels will static charges to acceptable levels will also be explored in this session.also be explored in this session.


Static Charge Static Charge ProblemsProblems

Charged surfaces will attract or repel Charged surfaces will attract or repel other charged surfaces. other charged surfaces.

Charged surfaces in machines will Charged surfaces in machines will cause:cause:– Paper JamsPaper Jams– Double Sheet FeedDouble Sheet Feed– Uneven Paper MovementUneven Paper Movement– Floating Paper Stacks Floating Paper Stacks – Contamination Problems Contamination Problems


Static Discharge Static Discharge ProblemsProblems

Static charges can build up to high Static charges can build up to high levels.levels.

An electrostatic discharge can result. An electrostatic discharge can result. The effects of electrostatic discharges: The effects of electrostatic discharges:

– Electric shock to personnel (mild to severe)Electric shock to personnel (mild to severe)– Permanent damage to circuit componentsPermanent damage to circuit components– Damage to interface displays (LED, LCD)Damage to interface displays (LED, LCD)– Damage to print headsDamage to print heads– Control system crashes (computer lockup)Control system crashes (computer lockup)– Hardware failures (bearing erosion) Hardware failures (bearing erosion)


Static Charge Static Charge GenerationGeneration

FrictionFriction SeparationSeparation InductionInduction


Triboelectric Triboelectric EffectEffect

Tribo means rubbing.Tribo means rubbing. Electrons are stripped away by Electrons are stripped away by

moving materials over stationary moving materials over stationary surfaces.surfaces.

Higher rubbing pressure increases Higher rubbing pressure increases the effect.the effect.

Faster speeds increase the resulting Faster speeds increase the resulting electrostatic charges.electrostatic charges.


Triboelectric seriesTriboelectric series

GlassGlass NylonNylon AluminumAluminum PaperPaper RubberRubber PVCPVC TeflonTeflon

Positive Charge (+)Positive Charge (+)

Negative Charge (-)Negative Charge (-)


SeparationSeparation

Separation of materials (like and unlike) Separation of materials (like and unlike) will create static charges.will create static charges.

Paper passing through rubber or plastic Paper passing through rubber or plastic rollers will acquire static charge. rollers will acquire static charge.

Paper passing through ungrounded metal Paper passing through ungrounded metal rollers will charge both paper and rollers.rollers will charge both paper and rollers.

Grounded conductive rollers will charge Grounded conductive rollers will charge paper during separation (roller charge paper during separation (roller charge will flow to ground).will flow to ground).


InductionInduction

When a charged surface is placed When a charged surface is placed near a conductive material, the near a conductive material, the charges in the conductive material charges in the conductive material will separate.will separate.

Grounded rollers will hold a charge Grounded rollers will hold a charge when near charged surfaces.when near charged surfaces.

Isolated conductive rollers will Isolated conductive rollers will experience charge separation when experience charge separation when in the vicinity of charged surfaces.in the vicinity of charged surfaces.


Factors effecting static Factors effecting static chargecharge

Low relative humidity will amplify static Low relative humidity will amplify static charge problems.charge problems.

Lighter grades of paper will be affected Lighter grades of paper will be affected differently than heavier grades.differently than heavier grades.

Coated paper will behave differently Coated paper will behave differently than uncoated paper.than uncoated paper.

Mylar sheets are worst case. Mylar sheets are worst case. Plastic frames and ungrounded metal Plastic frames and ungrounded metal

components augment static problems.components augment static problems.


Static Control SolutionsStatic Control Solutions

Design to reduce static Design to reduce static generation.generation.

Install Static Control Devices.Install Static Control Devices.


DesignDesign

Avoid sliding materials over surfaces as Avoid sliding materials over surfaces as much as possible.much as possible.

Use textured or ribbed surfaces to reduce Use textured or ribbed surfaces to reduce contact area.contact area.

Simplify paper path through machine to Simplify paper path through machine to minimize contact with rollers.minimize contact with rollers.

Use light pressures to move media Use light pressures to move media though equipment.though equipment.


Static Control DevicesStatic Control Devices

Static Control Devices use conductive Static Control Devices use conductive fibers placed near charged material to fibers placed near charged material to induce ionization.induce ionization.

The correct polarity of ions required to The correct polarity of ions required to remove the static charge are produced remove the static charge are produced at the fiber tips.at the fiber tips.

No power supply is required. No power supply is required. Most cost effective method to remove Most cost effective method to remove

static charges from insulated material.static charges from insulated material.


IonizationIonization

A charged surface will produce an electric A charged surface will produce an electric field perpendicular to the surface. field perpendicular to the surface.

+ + + + + + + + + + + + + + + + +



A sharp point placed near the field will A sharp point placed near the field will concentrate the field lines at the point.concentrate the field lines at the point.

+ + + + + + + + + + + + + + + + +



The air molecules near the point The air molecules near the point will ionize if the electric field will ionize if the electric field gradient exceeds the breakdown gradient exceeds the breakdown strength of air (3000 strength of air (3000 volts/millimeter).volts/millimeter).


Corona DischargeCorona Discharge

The ions created by the corona discharge The ions created by the corona discharge will follow the electric field lines to the will follow the electric field lines to the charged surface and reduce the charge.charged surface and reduce the charge.

Charged Surface


Static Control DevicesStatic Control Devices


Static Control Device Static Control Device ConstructionConstruction

Rigid - Two Aluminum Strips Rigid - Two Aluminum Strips bonded together with fiber bonded together with fiber between strips.between strips.


B

A

C

D E

F GH

Rigid Static Control Rigid Static Control DeviceDevice



Flexible - Single Aluminum or Flexible - Single Aluminum or Conductive Film Strip with Conductive Film Strip with fibers embedded into adhesive fibers embedded into adhesive backing.backing.


Flexible Static Control Flexible Static Control DeviceDevice

B

A

C

D E TYPICAL



FiberFiber– Carbon FiberCarbon Fiber– Stainless Steel FiberStainless Steel Fiber– Conductive Acrylic FiberConductive Acrylic Fiber


Carbon FiberCarbon Fiber

Most effective in reducing static Most effective in reducing static charge.charge.

Filament diameter is 7 μ-inch.Filament diameter is 7 μ-inch. 1000 to 3000 filaments per fiber 1000 to 3000 filaments per fiber

bundle.bundle. Should be installed to minimize Should be installed to minimize

shear forces when in contact with shear forces when in contact with media.media.


Stainless Steel FiberStainless Steel Fiber

Very effective in removing static Very effective in removing static charge.charge.

Filament diameter is 12 - 14 μm. Filament diameter is 12 - 14 μm. 90 to 275 filaments per fiber bundle.90 to 275 filaments per fiber bundle. Resilient material - will withstand shear Resilient material - will withstand shear

and abrasion, but may take on a “set” and abrasion, but may take on a “set” when bending contact with media is when bending contact with media is excessive.excessive.


Conductive Acrylic FiberConductive Acrylic Fiber

Effective in removing static charge.Effective in removing static charge. Filament diameter is 15 - 19 μm.Filament diameter is 15 - 19 μm. 10 to 90 filaments per fiber bundle. 10 to 90 filaments per fiber bundle. Resilient material - excellent for use Resilient material - excellent for use

when moderate shear and bending when moderate shear and bending forces are expected from contact forces are expected from contact with media. with media.


Static Control Device Static Control Device LocationLocation

Conductive fiber tips should be located 2 to 7 Conductive fiber tips should be located 2 to 7 mm from charged substrate.mm from charged substrate.

Conductive fibers should not touch substrate Conductive fibers should not touch substrate to ensure long life.to ensure long life.

A 5 mm clearance between the fiber tips and A 5 mm clearance between the fiber tips and machine surfaces will ensure optimal static machine surfaces will ensure optimal static control.control.

Static Control Device must be grounded. A Static Control Device must be grounded. A ground wire connection will be necessary if ground wire connection will be necessary if device is mounted on an insulated surface. device is mounted on an insulated surface.


ClearanceClearance

Provide 5 mm of clearance around fiber tips.Provide 5 mm of clearance around fiber tips. Provide air space beneath paper.Provide air space beneath paper.

Clearance

PaperAir Gap


MountingMounting

Static Control Device can be mounted at any Static Control Device can be mounted at any angle up to 90 degrees from charged surface.angle up to 90 degrees from charged surface.


Output Trays

Improper Location - charge suppressed1

Proper Location2

3 Best Location - beyond last point of charge generation

1

Glass plate

1

3

* Offset Static Control Devices if used on opposing sides for additional static control

General Schematic for Static Control Device Location

ADF

Imaging Drum

3 *

3 *

Input Tray

21

SORTER

IMAGER FUSER

Paper Path

2

Document Path

Document Tray

2

2

2

SCANNER

Electro Static Technology31 Winterbrook RoadMechanic Falls, Maine 04256Phone (207) 998-5140Fax (207) 998-5143E-mail [email protected]

Copyright 2001 Electro Static TechnologyAll Rights Reserved


Additional Static Control Device Locations in Machines

Conductive roller which is isolated by nylon bearings can be grounded through a Static Control Device in contact with the shaft

TRANSFER BELT

ISOLATED CONDUCTIVE ROLLER

INSULATED ROLLER

Insulated roller static charge can be reduced through a Static Control Device installed along the full length of the roller

Transfer Belt static charge can be reduced by Static Control Devices installed along the full width of the transfer belt and rollers as shown

PAPER SENSOR

The presence of paper in a machine can be detected by a Static Control Device used as a soft contact sensor

Electro Static Technology31 Winterbrook RoadMechanic Falls, Maine 04256Phone (207) 998-5140Fax (207) 998-5143E-mail [email protected]

Copyright 2001 Electro Static TechnologyAll Rights Reserved


SummarySummary

Static charges are created by friction, Static charges are created by friction, separation, and induction.separation, and induction.

Static charges cause many problems in Static charges cause many problems in paper transport equipment.paper transport equipment.

Electrostatic discharge can damage Electrostatic discharge can damage electronics and hardware.electronics and hardware.

Proper location of Static Control Proper location of Static Control Devices is critical for effective charge Devices is critical for effective charge reduction. reduction.


Contact InformationContact Information

For the best in passive static solutions For the best in passive static solutions contact us today!contact us today!

Immediate assistance for design, Immediate assistance for design, application, samples, or pricing is just a application, samples, or pricing is just a phone call, email or fax away.phone call, email or fax away.

Would an on-site technical presentation Would an on-site technical presentation be helpful? Contact us and lets discuss it.be helpful? Contact us and lets discuss it.

Direct personal assistance from both our Direct personal assistance from both our USA and Far East sales departments.USA and Far East sales departments.


USA Contact USA Contact InformationInformation

Address: Electro Static TechnologyAddress: Electro Static Technology

31 Winterbrook Road31 Winterbrook Road

Mechanic Falls, Maine 04256Mechanic Falls, Maine 04256 Email: Email: [email protected]@est-static.com Phone: Phone: 207 998-5140207 998-5140 Fax:Fax: 207 998-5143 207 998-5143


Far East Contact Far East Contact InformationInformation

Address: Electro Static Technology, JapanAddress: Electro Static Technology, Japan

1-2-4 Minatojima-Nakamachi, 1-2-4 Minatojima-Nakamachi, Chuo-ku,Chuo-ku, Kobe, 650-0046 JapanKobe, 650-0046 Japan

Email: Email: [email protected]@est-static.com Phone: Phone: 81-78-303-641381-78-303-6413 Fax:Fax: 81-78-303-4655 81-78-303-4655

static charge solutions presentation by: electro static technology

Documents

n electrons

static problems

n grounded rollers

static generation

n plastic frames

n lighter grades of

n faster speeds

n mylar sheets