MIL-PRF-83671 – Foam-In-Place Packaging Materials,

General Specification

Subject/Scope: This specification covers flame retardant polyurethane foams for packaging furnished as

two-component liquid foam0in-place (FIP) systems (See 6.1)..

Keywords: Specimen, mil, requirement, material, class, sample, temperature, test, packaging, specification,

compression, ASTM, stress, static, safety, health, container, inspection, standard, equipment, foam,

MSDS, deflection, government, force, orientation, isocyanate, creep, method, cushioning, chemical

methylene, component, load, exposure, drop, formulation, contract, CFR, military, bun, industrial,

polyurethane, hydrolytic, bisphenyl

Published: 2/3/1997

Text in blue boxes such as this one is instructional and is intended to assist you in understanding the document.

Text in red boxes such as this explains changes made to the document by The Wooden Crates Organization.

Red text has been added to the document or modifies the document since its final version was officially published.

Soft Conversion of Imperial to Metric

Conversions, when made, consider materials that are available in metric or imperial sizes rather than converting

sizes exactly. For example: Panelboard (plywood) in the US is typically 4 feet X 8 feet (1220 x 2440 mm) while

panelboard in metric countries is typically 1200 X 2400 mm. Since the standard was developed based on readily

available materials these variations in material sizes could not have been practically considered.

The content of the document below has not been modified.

wMIL-PRF-83671B

3 February 1997SUPERSEDING

MIL-F-83671A15 September 1993

MILITARY SPECIFICATION

FOAM-IN-PLACE PACKAGING MATERIALS, GENERAL SPECIFICATION FOR

This specification is approved for use by allDepartments and Agencies of the Department of Defense.

1. SCOPE

1.1 m. This specification covers flame recardancpolyurethane foams for packaging furnished as two-componentliquid foam-in-place (FIP) systems (see 6.1).

1.2 The polyurethane foams and the rawmaterials for the foams shall.be furnished in the followingclasses, grades and categories. Additional characteristics shallbe specified by the procuring activicy (see 3.3.9, 6.2 and 6.5):

Class 1 - Rigid

Category 1 -Category 2 -

Class 2 - Flexible

Conventional StrengthHigh Strength

Grade A - (Figure 1)Grade B - (Figure 2)(Use Grade with Class 2 only)

Beneficial comments (recommendations, additions, deletions)and any pertinent data which may be of use in improvingthis document should be addressed co the Air Force PackagingTechnology and Engineering Facility, AFf.fCLSO/LOP: 5215 ThurlowStreet, Wright Patterson AFB OH 45433-5540, by usxng theStandardization Document Improvement Proposal (DD Form 1426)appearing ac the end of this document or by letter.ANSC N/A FSC 8135

~. Approved for public release;distribution is unlimited.

MIL-PRF-83671B

Class 3 - Semi-Rigid (Figure 3)

2. APPLICABLE DOCUMENTS

2.1 ~. The documents listed in this section are specifiedin sections 3 and 4 of this specification. This section does notinclude documents cited in other sections of this specificationor recommended for additional information or as examples. Nhileevezy effort has been made to ensure completeness of this list,document users are cautioned that they must meet all specifiedrequirements documents cited in sections 3 and 4 of thisspecification, whether or not they are listed.

2.2.1 The followingspecifications and standards form a part of this document to theextent specified herein. Unless otherwise specified, the issuesof these documents are those listed in the issue of theDepartment of Defense Index of Specifications and Standards(DODISS) and supplement thereto, cited in the solicitation (see6.2).

STANDARDS

FEDERAL

FED-STD-101 Test Procedures for Packaging MaterialsFED-STD-313 Material Safety Data, Transportation

Data and Disposal Data for HazardousMaterials Furnished to GovernmentActivities

HANDBOOKS

Military

MIL-liDBK-775 Foam-In-Place Packaging, Procedures for

(Unless otherwise indicated, copies of federal and militaryspecifications and standards are available from cheStandardization Documencs Order Desk, Building 4D, 700 RobbinsAve. , Philadelphia, PA 19111-5094. )

2.2.2 The followingother Government documents and publications form a part of thisdocument to the extent specified herein. Unless otherwisespecified, the issues are those cited in the solicitation.

DEPARTMENT OF ’TRANSPORTATION (DOT)

Title 49, Code of Federal Regulations, Parts 100-199.

OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION (OSHA)

2

MIL-PRF-83671B

Title 29, Code of Federal Regulations, Part 1910.1200

Occupational Safety and Health, Volume I, General IndustryStandards and Interpretations, Part 1910.

(Applications for copies should be addressed to theSuperintendent of Documents, US Government Printing Office,Washington, DC 20402.)

2.3 ~.. .

The following documents form apart of this document to the extent specified herein. Unlessotherwise specified, the issues of the documents which are DoDadopted are those listed in the issue of the DODISS cited in thesolicitation. Unless otherwise specified, the issues ofdocuments not listed in the DODISS are the issues of the cited inthe solicitation (see 6.2).

AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM)

ASTM-C421

ASTM-D471

ASTM-D1596

ASTM-D1621

ASTM-D1623

ASTM-D2126

ASTM-D5118

ASTM-E96

Tumbling Friability of Preformed, Block-TypeThermal Insulation, Standard Test Method for(DoD Adopted)Rubber Property - Effect of Liquids, Test Methodfor (DOD Adopted)Dynamic Shack Cushioning Characteristics ofPackaging Materials, Standard Test for (DoDAdopted)Compressive Properties of Rigid CellularPlastics, Standard Test Method for (DoD Adopted)Tensile and Tensile Adhesion Properties of RigidCellular Plastics (DoD Adopted)Response of Rigid Cellular Plastics to Thermaland Humid Aging, Standard Test Method for (DoDAdopted)Standard Practice for Fabrication of FiberboardShipping Boxes (DoD Adopted)Water Vapor Transmission of Materials (DoDAdopted)

(Application for copies should be addressed co ASTN, 100 BarHarbor Dr.. West Conshohocken PA 19103.)

2.4 ~. In the event of a conflict between thetext of this document and che references cited herein, the textof this document takes precedence. Nothing in this document,however, supersedes applicable laws and regulations unless aspecific exemption has been obtained.

3

MIL-PRF-83671B

3. REQUIREMENTS

3.1 First ar~ When specified (see 6.2), asample shall be subjected to Eirst article inspection (see 6.3)in accordance with 4.2.2.

3.1.1 The foam dispensing equipmentused to prepare samples for qual~fication as specified hereinshall be clearly listed in the Certificate of Compliance preparedby the foam-in-place packaging suppliers. A chemical formulationshall be certified as complying with the requirements of thisspecification when the samples tested are dispensed throughapproved foam dispensing equiPment from the supplier of thechemical formulation. Use of this foam dispensing equipment isrequired to certify compliance with the requirements of thisspecification.

3.2 The materials used in the production ofpolyurethane foams shall provide a product conforming to therequirements specified herein.

3.2.1 Formulations shall be supplied as atwo-component liquid system of a polymeric isocyanate typeconsisting of component A (primarily methylene bisrhwlisocyanate compounds) and component B (polyol compounds) suitablefor mixing in foam equipment such as portable systems, semi-porcable systems, fixed systems, mechanical pump systems,pneumatic pump systems, compressed gas displacement systems(fixed proportioning or variable proportioning), or any systemcapable of producing a product conforming to the requirements ofthis specification, and using the procedures recommended inMIL-HDBK-775 . Methylene diisocyanate (MDI) is a commonly usedmisnomer for diphenyl methane diisocyanate and methylenebisphenyl isocyanate. Nevertheless, the more commonly used term,MDI , shall be used in this document. The formulation shall notconcain materials which are chemically nonreactive (such asfillers and nonreactive diluents) except for surfactants, firerecardanc agents, noncombining catalysts and blowing agent.There shall be no separation of chemical components, stringinessor coagulated particles that will tend to clog dispenser linesand filters of the foam-in-place dispensing equipment.Chlorofluorocarbons (CFCS) or hydrochlorofluorocarbons (HCFCS)shall not be purposely added to any formulation. Where presentas a trace or impurity, CFC/HCFC shall be maintained at thelowest feasible levels. Under no circumstances shall CFC/HCFC bepresent in the product at levels that exceed a specifiedpercentage, by weight. Use of 0.1 percent (maximum, by weight)is recommended.

3.2.1.1 A product information sheet shallaccompany each shipment of chemicals. The sheet, as a minimum,shall provide an item description, chemical and physicalproperties, handling instructions, and precautions. It shallinclude the temperature ranges at which the components must be

4

MIL-PRF-83671B

conditioned prior to foaming. This temperature range shall be inaccordance with Table I unless otherwise specified by theprocuring activity.

3.2.1.2 Per (~ ‘l’heconcraccingactivity shall be provided a Material Safe~y Data Sheet (MSDS)prior to contract award. The MSDS shall be prepared andsubmitted in accordance with 29 CFR 1910.1200. The MSDS shall beincluded with each shipment of the material covered by thisspecification. Contracting officers will identify thoseactivities requiring copies of compleced MSDSS prepared inaccordance with FED-STD-313 and 29 CFR 1910.1200. The pertinentgovernment mailing addresses for submission of data sheets arelisted in Appendix B of FED-STD-313. The Material Safety DataSheet Receipt Point for Navy and Marine Corps is as follows:Commanding Officer, Industrial Hygiene Directorate (Accn:HAZMAT), Navy Environmental Health Center, 2510 Walmer Avenue,Norfolk, VA 23513-2617.

3.2.1.2.1 A hazardousmaterial warning label conforming to 29 CFR 1910.1200 shall be arequirement for each unit of issue.

3.2.2 Foams shall exhibit the properties shown inTable I. Unless otherwise specified, the properties listed arefor ambient temperatures of 18°C co 27°C.

3.2.3 ~.

3.2.3.1 The formulations shall not containtoluene diisocyanate (TDI), TDI derivatives, methylene chloride(dichloromethane) , or any substances regulated as carcinogens inCode of Federal Regulations, Title 29, part 1910, subpart Z ofvolume 1, General Industzy Standards and Interpretations ofOccupational Safety and Health Administration. Do not includeany materials that are considered: Occupational Safety andHealth Administration (OSHA) regulated carcinogens,known/suspected human carcinogens by che International Agency forResearch on Cancer (IARC) (lacesc reports) and/or the NationalToxicology Program (NTP) (latest annual report) and/or NavyOccupational Chemical Reproductive Hazards should be excludedfrom these formulations. The absence of TDI and TDI derivativesshall be determined prior to the initial mixing of components forfirst article testing.

3.2.3.2 ~ Navy procurements shall be inaccordance with the requirements of 3.2.3.2.1.

3.2.3.2.1 li=nf= t!= ((-AS101-- 8.LFor Navy procurements, the manufacturer or

supplier shall: “

MIL-PRF-83671B

a. Disclose the complete information for the product via theMaterial Safety Data Sheet (MSDS) in sufficient detail to permitan accurate appraisal of the likelihood of generation ofmethylene bisphenyl isocyanate and other potentially toxic gases,vapors, aerosols, etc. during any anticipated utilization of the

TJ@LEI. ~.

~ CLAss 1 ~< 3 f<m.fr.~

1Conditioning 29°c (COrnPA) 32°C (CompA) 35“c (Comp A)

temp.,range 15°C 29°C (CampS) 32°C (CampS) 35°C (CompS)to specifiedcemperacure

2Cream time, 40 30 30

seconds (ma.x)

2Rise time, 120 90 90

seconds (max)

aTack free time, 150 150 150

seconds [w)

3Reaccion temp., 205°c 177°C 177°c

(Max)

Cure time co 72 hrs max 72 hrs max 72 hrs maxobtainall mech-anicalproperties

1See 3.2.1.1

2See 6.8

1See 3.3.11and 4.3.3.11,and 6.7

24°c (campA)

24°C (CompB)

5

30

3s

163°C

72 hrs w

product. This will require submission of a listing of allingredients, totaling 100 percent of the formulation, as well asche submission of a current MSDS for each ingredient used in theformulation. The manufacturer shall contact each ingredientsupplier within thirty days of documentation submission, in orderto certify that each MSDS provided is current. The MSDS shallcontain all data elements required by an OSHA Form 174, usingthis form or similar form containing identical information. Thisdata will be required for occupational health professionals toperform a proper health hazard assessment of the product. Inaddition, where toxicological andlor industrial hygiene studieshave been performed involving the product, copies of thesereports shall also be provided as part of the documentationpackage. Where the product is in commercial use, a minimum ofthree large-scale users of the product must be identified, withoccupational safety/health points of contact, for follow-up bygovernment personnel performing the health hazard assessment.

6

MIL-PRF-83671B

b. Provide specific precautionary measures, includin9 anMSDS, with each unit of issue to ensure safe use of the product.

Forward the MSDS and addendum to the address specified in6.14=”

3.3

3.3.1 . Foams shallcomply with mixing requirements of 3.2.1 and shall be prepared inaccordance with 4.3.1. Test. specimens shall conform to thefollowing parameters:

a. Specimens shall be homogeneous and contain no knit lines.

b. Maximum allowable dimension of blow holes is 13 nun. Theconcentration of 13 mm diameter blow holes shall not exceed onein 100 square centimeters (10 cm x 10 cm) .

3.3.2 Unless otherwise specified,materials shall meet the requirements of 3.3.2.1 or 3.3.2.2 asapplicable (see 6.2 and 6.6).

3.3.2.1 QaseuL. After aging in accordance with 4.3.3.2, theaverage minimum compressive strength of the 15 samples tested inboth the parallel and the perpendicular directions.(see4.3.3.2.1) at yield or 10 percent deflection, whichever is firstco occur, shall not vary more than 10 percent from the averagevalue of the 15 samples tested in both the parallel and theperpendicular directions obtained prior to aging (see 4.3.3.9 and6.5). It is noc necessary for both yield and ten percentdeflection to occur.

3.3.2.2 ~. After aging in accordance with4.3.3.2, the stresses necessary for 20 and 40 percent strainsshall be within ~ 10 percent of the stresses necessary to causethese same strains on the same unaged specimens when tested inaccordance with 4.3.3.2.3.

3.3.3 The average water absorptionby weight, of all the samples, shall not exceed 170 percent whendetermined in accordance with 4.3.3.3.

3.3.4 ~. Unless otherwise specified (see6.21 the maximum percentage creep that occurs under thecontinuous loading stress necessary to cause an initial 20percent strain shall not exceed 15 percent when tested inaccordance with 4.3.3.4.

3.3.5 Unless otherwisespecified (see 6.2), the compression20 percent of the original thickness

7

sec shall not be more than(see 4.3.3.5).

MIL-PRF-83671B

3.3.6 Unless otherwise specified(see 6.2), the material shall show no cracks, tears orseparations when tested in accordance with 4.3.3.6. Thisrequirement is limited to materials having a density of 0.064 x

103 kg/cm3 or less.

3.3.7 ~. The average change in volume of allurethane foam samples after aging shall not be greater than 7percent of the initial volumes before aging (see 4.3.3.7).

3.3.8 The urethane foam shall betested in accordance with 4.3:3.8. The flame front of eachspecimen shall not advance co or beyond the 125 nungage markspecified in the test. There shall be no visual evidence ofburning or melting of any specimen at or beyond the 125 mm gagemark. Chlorinated or brominated additives shall not be used forfire retardancy.

3.3.9 Unless otherwisespecified (see 6.2), the minimum compressive strength ac yield or10 percent deflection, whichever occurs first, shall be asfollows (see 4.3.3.9):

Category 1 - 1.50 Kg/c# parallel and 0.85 Kg/cm’perpendicular to the direction of foam rise.

Category 2 - 2.00 Kg/cmz parallel and 1.00 Kg/cmaperpendicular to the direction of foam rise.

It is not necessaz+ for both yield and ten percent deflection cooccur. Failure of the average compressive strength value of anysec of five specimens to conform to the above requirements shallbe cause for rejection. When a category is not specified, therequirements for category 1 shall apply.

3.3.10. .1-c~ @s (rl~?=s 2 The

peak G-static stress curves for class 2, grades A and B: andclass 3 shall conform to the shapes of the appropriategeneralized curves, presented in figures 1, 2, and 3, within chespecified tolerance bands of L 15 percent when tested inaccordance with 4.3.3.10. Five peak G-static stress points,approximately equally spaced, shall be required to establishconformance of the class 2, grades A and B materials. l’wopointsshall be established within 10 percent of the static stressvalues at the extremities of the curve and one at the approximateminimum peak acceleration level point. Three peak G-staticstress point shall be required to ~stablish conformance of the

class 3 material, one at 0.02 x 10a Kg/cma, one at 0.045 x 101

Kg/cmz, and one at 0.10 x 101 Kg/cm (see Table II and 6.4).

MIL-PRF-83671B

3.3.11 ~ react~. The maximum reactiontemperature (see 4.3.3.11) shall not be greater than the valueslisted in Table I.

3.3.12 (~. The average linearchange when tested in accordance with 4.3.3.12 shall not exceed 5percent.

3.3.13 ~. When tested in accordance with 4.3.3.13, thecured foam product, prepared by machine dispensing equipment,shall not have a weight loss greater than 14 percent for class 2and 3 specimens and not have a weight loss greater than 20percent for class 1 specimens.

3.3.14 ~P str~. When specified (see 6.2),the test specified in 4.3.3.14 shall be performed. The tensile

strength shall be 2.5 Kg/cm= minimum on parallel specimens and

2.0 Kglcm2 minimum on perpendicular specimens.

3.3.15 MQi5tllre,.

va~tv (rl~. When specified(see 6.2), the test specified in 4.3.3.15 shall be performed.The maximum moisture vapor permeability shall be

4 x 10-9 g/(Paxsxm).

3.3.16 Qil re~sl. When specified (see 6.2), thetest specified in 4.3.3.16 shall be performed. There shall be nosoftening of the oil-immersed samples.

3.4 ~. Manufacturers shall submitcertification that components will meet the requirements of thisspecification after storage (between 10°C and 35°C) for one year,beginning at time of delivery. Components shall be in theiroriginal containers, and no additional agitation shall berequired prior to foaming operations.

3.5

3.5.1 In addition to any special or otheridentification marking required by this specification or theconcract (see 6.2) , containers and unitized loads shall be markedin accordance with 49 CFR Parts 172, subpart D and 178, subpartL, as applicable.

3.5.2 l&dze_k. Labels attached to each container shall complywith the OSHA Hazard Communication Standard, 29 CFR 1910.1200,and 49 CFR 172, subpart E. Each container shall be marked on thesides, using waterproof labels, with the following minimuminformation:

a.

idenc:Manufacturer’s name, address, and proprietary

fication.

9

W$[iwitlm$c

wsLxwR(lotlcQoot

Vln

VIN

UJO;l=

OH

X-O

S

cus~xcaootrwcot

E

Y/n

ala[lxcaoslr~o$l

U9Sclcnitt=sc

‘aas Lxmloozr=oot

YIN

Vin

9011

WO

SIX

=OS

‘saf~xcuoocx=ooz

Vln

Ua(lxmo$lx’=osl

~~LZ-ootxwoot

Qaslzwoocz-oot

cJ$LZ=Oo[Z=oot

~sl

zwoo

txw

aoc

VIN

vIN

VIN

VII

I

mT-inn

~rm

vnm

uXmnmu

am

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.l~nlllTrTrmu

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UIQ

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MIL-PRF-83671B

b. Specification classification (class and grade).

c. Handling precautions - each container of isocyanate shallhave the following label:

WARNING: MAY CAUSE EYE, NOSE AND THROAT IRRITATION. MAYCAUSE SHORTNESS OF BREATH DUE ‘IUAN ALLERGIC RESPIRATORYREACTION (e.g., ASTHMA AND LUNG INFLAMMATION) . NAY CAUSESKIN IRRITATION AND ALLERGIC REACTIONS. Use appropriateprotection as designated by responsible industrial hygienepersonnel. Consult the MSDS and product labels foradditional guidance to ensure the safety of this operation.

m not OPt In eves, on

~.

“..up wi~te v~.

d. Storage life and expiration date (month, day and year).

e. Date of manufacture (month, day and year).

f. Mixing ratio by weight and volume

9. Manufacturer’s batch or lot number.

h. C)peracion and storage temperature ranges.

Component designation (-A- for isocyanate, “B” forpOly~i).

j. The following notation: “For foaming operations IAWMIL-PRF-83671B; the mixing of the contents of this container withany product ocher than this manufacturer’s designated product isexpressly forbidden.”

3.5.3 All containers shall be color coded on the

top and sides with a label measuring 1936 cma minimum on sides

and 968 cmz minimum on top as follows:

a. “A” component: red or yellow.

b. “B” component: blue.

4. VERIFICATION

4.1 of The inspection requirementsspecified herein shall be classified as follows:

a. First article inspection (4.2.2)

II

MIL-PRF-83671B

b. Conformance inspection (4.2.3)

4.2 d tl=st~.

4.2.1 -c ar~. First article inspection may bewaived, by the Air Force Packaging Technology and EngineeringFacility (AFPTEF) or the procuring activity, when the procuringactivity or contract administrator has data or other evidence toindicate that prior successful first article inspection has beenconducted (see 6.2) . Only when the first article has been waivedby the AFPTEF or procuring activity, may the contractor self-certify that the material will conform to the requirements ofthis specification.

4.2.2 -t ar~ First article inspection shallconsist of all cescs in Table III and shall be performed by thecontractor, after award of contract and prior to production.First article inspection shall be performed on sample unitsproduced using materials, equipment, and procedures which will beused in fulfilling the contract. First article approval is validonly on the contract on which it is granted, unless extended bythe Government to other contracts (see 3.1 and 6.3). In case ofdispute, the procuring activity shall require testin9 oncontractor supplied material be performed by either AFPTEF or anindependent lab.

4.2.3 Quality conformance tests shallconsist of all tests in Table IV.

4.3 The tests specified in Tables III and IV shall beperformed to assure compliance with the requirements in section3. No material shall be tested until che absence of TDI has beenverified in accordance with 3.2.3.1.

4.3.1 of test Foams shall comply withthe mixing requirements in 3.2.1. “

4.3.1.1 To produceclass 1 test samples, ic is recommended that foam shall be pouredinto a 300 nun x 300 nun x 300 nun rigid container lined withpolyethylene film material. A minimum of six 300 nun x 300 mm x300 m buns shall be prepared. The poured foam shall be allowedto cure for a minimum of 72 hours before cutting test specimens.

4.3.1.2 To produce testspecimens for classes 2 and 3 with the dimension of thicknessperpendicular to the direction of foam rise (perpendicularorientation) , it is recormnended that foam shall be poured into a800 mm x 200 mm x 400 mm (L x W x H) or larger rigid containerlined with a polyethylene sheet material. To produce testsamples with the dimension of thickness parallel to the directionof foam rise (parallel orientation) , it is recormneded that foamshall be poured into a 800 mm x 400 mm x 200 nun (L x W x H) orlarger rigid concainer lined with a polyethylene sheet material.

MIL-PRF-83671B

TASLE III. ~.

~

ToXiCiKy (airborne) 3.2.3.2.1

Quality requirements 3.3.1for test specimens

Hydrolytic scabilicy 3.3.2

Water absorption 3.3.3

Creep

compression set

Pliability

volume change 3.3.7

combustibility 3.3.8

Compressive screngch 3.3.9

Oynamic cushioning

Naximum reaccion 3.3.11 &cemp. Table I

Cold temperature 3.3.12scabilicy

Friability 3.3.13

Tensilestrength 3.3.14(whenspecifiedbyprocuringaccivity)

Moisture vapor 3.3.15permeabil icy(whenspecifiedby procuringaccivity)

Oil resistance(when 3.3.16specifiedbyprocuringaccivity)

Shelf life 3.’I

3.2.3 .2.1 3 .2.3.2.1 4 .3.3.1.1

3 .3.1

3 .3.2

3.3.4

3.3.5

3.3.6

3.3.7

3.3.8

3.3.10

3.3.11&Table 1

3.3.13

3.4

3.3.1

3.3.2

3.3.4

3.3.5

3.3.6

3.3.7

3.3.8

3.3.10

3.3.11&Table I

3.3.13

3.4

Noc Applicable

4.3.3.2

4.3.3.3

4.3.3.4

4.3.3.5

4.3.3.6

4.3.3.7

4.3.3.8

4.3.3.9

4.3.3.10

4.3.3.11

4.3.3.12

4.3.3.13

4.3.3.14

4.3.3.15

4.3.3.16

Not Applicable

TABLE IV.

Combustibility 4.3.3.8

Identification (drums or canister) 3.5 (visual)

13

MIL-PRF-83671B

The poured foam for both orientations shall be allowed to curefor a minimum of 72 hours before cutting test specimens.

4.3.1.3 All specimen material shall betaken from the center section of the bun and shall not includeany material within 50 nunof any face of the bun. The specimenmaterial shall be homogeneous with no knit lines in the material.A knit line is defined as a visible line in the foam where two ormore sections of partially cured material have come in concactwith each other during the pour. The concentration of holes withmaximum dimension of 13 mm shall not exceed one in 100 squarecentimeters (10 cm x 10 cm) . No holes shall be larger than 13mm. Samples for specific testing shall be prepared in accordancewith Table II. All samples with a perpendicular orientationshall be cut so that the dimension of thickness is perpendicularto che direction of foam rise. All samples with a parallelorientation shall be cut so that the dimension of thickness isparallel to the direction of foam rise (see Figure 4) .

4.3.1.4 Materials used for testingshall be selected randomly without regard co apparent qualitybased on visual appearance. However, all specimens selected fortesting shall be free of skins and cut so as to avoid rounded orcompressed edges.

4.3.1.5 ~ All faces ofspecimens shall be rectangular, having dimensions in accordancewith the appropriate test requirement.

4.3 .1.5.1 of len~. The length and widthof each specimen shall be measured at the center line to thenearest 2 mm.

4.3.1.5.2 of Measure thickness byplacing che specimen on a flat, level surface. Load its entiretop surface to 175 Pa L 35 Pa using a rigid, flat plate. APL)lythis load for 30 seconds and then measure the vertical distancebetween che base surface and the bottom of the loading plate tothe nearest 2 mm. This measurement may be made either by asingle point at the center of the cushion top surface or at eachof the four corners of the sample. If the four-corner method isused, the average of the four measurements shall be the thicknessof the specimen. The thickness of the material shall be theaverage thickness of the specimens used for testing.

4.3.1.6 Nhen required, prework specimens using acompression machine (Instron Compression Tester or equivalent) .The machine shall utilize 2 parallel rigid plates large enough tocover the entire surface of a specimen.

a. Set the initial and final distance between the compressionplates as specified in the appropriate procedures.

14

MIL-PRF-83671B

b. Program the machine to compress each specimen 10 times ata rate of 250 mm per minute.

4.3.2 Tests and measurements shall be made atroom temp”erature, 21°C - 27°C. In case of dispute or rejection,the specimens shall be conditioned at 23°C A 1°C and 50 percentrelative humidity (RH) ~ 5 percent RH for at least 16 hoursbefore being tested or preworked.

4.3.3 ~.

4.3.3.1 ~. .

For Navy procurements,methylene bisphenyl isocyanate (M&) concentrations shall bedetermined by methods and procedures described in paragraph 6.14.

4.3.3.2 Vtlc The hydrolytic stability testshall be performed using the appropriate test sequence specifiedbelow. Except for aging, the environmental conditions ofparagraph 4.3.2 shall apply. Aging shall consist of exposure oftest specimens for 14 days at 70°C A 1°C and 95 percent RH i 5percent RH. After exposure, the specimens shall be subjected to49°C ~ 1°C in a mechanically convected dw air oven for 24 hours.

4.3.3.2.1 Hydrolyticscabilicy for class 1 materials shall be determined on samplesobtained after a minimum 72-hour cure time. Five specimens,100 mm x 100 nunx 50 mm, shall be cut from each of three 400 mm x400 mm x 400 mm single pour blocks of foam (see Table 11) suchthat the dimension of sample thickness (50 mm) is parallel to thedirection of foam rise (see Figure 4). Additionally, fivespecimens, 100 mm x 100 nuox 50 mm, shall be cut from each of thethree sample blocks such that the dimension of sample thicknessis perpendicular to the direction of foam rise (see Figure 4) .Specimens shall be aged as specified in 4.3.3.2. These specimensshall then be tested for compressive strength values at yield orten percent deflection, whichever occurs first. It is notnecessary for both yield and ten percent deflection to occur.Failure of the average compression strength value, recorded foreach sec of five specimens, to conform to the requirements of3.3.2.1 shall be cause for rejection.

4.3.3.2.2 l’~sr -P~ for cla~s 2

a. Cut six samples, 200 mm x 200 mm x 75 nun, three withparallel orientation and three with perpendicular orientation,prepared in accordance with 4.3.1 (see Table II).

b. Condition specimens in accordance with 4.3.2.

c. Measure the original thickness in accordance with4.3.1.5.2.

d. Prework the specimens, 48% of their original thickness, inaccordance with 4.3.1.6.

MIL-PRF-83671B

e. One hour after preworking the specimens. measure initialthickness for the load/deflection test in accordance with4.3.1.5.2.

f. Perform the load/deflection test in accordance with4.3.3 .2.3 using the initial thickness from 4.3.3.2.2.e todetermine the 20 and 40 percenc strain points.

9. Age the specimens as specified in 4.3.3.2.

h. Condition specimens for a minimum of 60 minutes inaccordance with the temperature and humidity conditions of 4.3.2.

Prework the specimens, 48% of their original thickness,in a~cordance with 4.3.1.6.

j. Repeat the load/deflection test on aged specimens inaccordance with 4.3.3.2.3 using the initial thickness from4.3.3.2.2.e to determine the 20 and 40 percent strain points.

k. To determine compliance with 3.3.2.2, use the pre-agingand post-aging loadldeflection test data to calculate the percencof change for specimens cut parallel to the direction of foamrise. Repeat the calculations for specimens cut perpendicular cothe direction of foam rise. The percent of change averages foreach group of three shall be used to comply with 3.3.2.2, withthe absolute numbers used (regardless of i signs) .

4.3.3.2.3 This test shall beperformed using a compression machine as des~ribed in 4.3.1.6.

a. Set the initial distance between the compression placesto ensure that all cushions will fit easily between the plates.

b. Set the final distance between the plates to 4 nun.

c. Program the machine to compress the specimens at a rateof 5 mm per minute with auto reverse at the end of thecompression stroke to return the compression plate to its initialposition.

d. Compress each cushion once while recording the forceapplied at the 20 and 40 percent strain points during thecompression half of the cycle.

4.3.3.3 hiarer ~ (r—~ Three samples shall betested and examined for conformance”to che requirements of 3.3.2.Water absorption shall be determined in accordance with thesubmersion technique of Method 4035 of FED-STD-101 with thefollowing exceptions:

a. The balance used shall be accurate to * 0.01 9ram with areadability of 0.01 gram.

16

MIL-PRF-83671B

b. Test specimens shall be weighed to the nearest 0.01 gram.

c. Test specimens shall be 100 mm ~ 2 mm square by 25 mm ~ 2mm thick.

d. Test specimens shall be submerged in a vessel containingdistilled water maintained at 21°C to 24°C.

e. The submersion period shall be 96 hours 2 1 hour.

4.3.3.4 2 and U Threespecimens, 150 mm x 150 mm x 75 mm, with 75 nundirection parallelto foam rise, shall be prepared in accordance with 4.3.1.Prework specimen to 60 percent of its original thickness inaccordance with 4.3.1.6. Initial thickness shall be measured inaccordance with 4.3.1.5.2. Three minutes after the lastcompression, the thicknes~ of each specimen shall be measured

with a 0.41 kg, 0.24 x 10 Kg/cma, preload in accordance with4.3.1.5.2. This thickness measurement shall be used as the

initial thickness unloaded (Ti) in the compression setcalculation. The test specimens shall be loaded to 20 percentinitial strain. One hour after continuous loading, the thickness

shall be measured and recorded as initial thickness loaded (ti)for the determination of creep. The specimens shall remain underconscant load, and thickness measurements shall be recordedapproximately every 24 hours for a total of four 24-hourincrements or until the variation between two successive

measurements does not exceed one percent of ti. The final

measurements shall be recorded as t~. The percentage of creepshall be calculated as follows:

(t, - tf) x 100Percentage of creep =

ti

Where Ci = initial thickness loaded

K~ . final thickness loaded

The creep of the material in a lot shall be the average of thecreep of che three specimens (see 3.3.4) .

4.3.3.5 SPS 2 This test shall beconducted immediately following the test specified in 4.3.3.4.using the same specimens. Four hours after the load is removed,the specimen thickness shall be measured in accordance with4.3.3.4 and the compression set calculated as follows:

[T, - Tf) X 100

MIL-PRF-83671B

Compression set =

T,

Where T1 = initial thickness unloaded from paragraph4.3.3.4

Tc . final thickness after 4 hours in unloadedcondition

The percent compression set of the material in a lot shall be cheaverage percent compression set of the three specimens.

The result shall not exceed the requirements of 3.3.5.

4.3.3.6 ~tv (C~ 2 Three samples 150 nunx150 mm x 13 nun,with parallel orienta~ion, shall be prepared asspecified in section 4.3.1 (see Table II, and 4.3.1.3). Withintwo seconds, each of three specimens shall be bent 180° around acylinder having a 13 mm diameter in a uniform manner such thatthe foam shall be pressed against the cylinder. The test shallbe conducted at room temperature (see 4.3.2) and at -40”C. Forthe low temperature test, the specimens shall be conditioned forat least four hours at -40°C and then bent at that temperatureor, if not practical, within 5 seconds after removal from the lowtemperature environment. Each specimen shall be examined forconformance with 3.3.6.

4-3.3.7 ~. Three test specimens, prepared asspecified in 4.3.1 and conditioned according co 4.3.2, shall bemeasured and the volume calculated and recorded. The class 1specimens shall be 100 mm x 100 mm x 50 mm, aged as specified in4.3.3.2, and re-measured in accordance with ASTM-D2126. Theclass 2 and 3 specimens shall be 200 nunx 200 nunx 75 mm andsubjecced to the temperature and humidity conditions only,specified in 4.3.3.2, and re-measured. The volume change of eachsample shall be calculated and expressed as a percenc of theinitial sample volume. The average percenc volume change of thesamples shall conform to 3.3.7. Final measurements shall be madeinnnediacely following aging.

4.3.3.8 The combustibility of the foamshall be determined in accordance with the followingsubparagraphs . After completion of the test, foam samples shallbe examined for conformance to 3.3.8. A test shall consist ofdetermining the extent of burning of at least five foam samples.Samples shall be cut from sections ac least 40 mm from exteriorsurfaces. The thickness of each sample shall be parallel to thedirection of rise.

4.3.3.8.1 Amua.us.

a. Test chamber. The chamber shall be constructed ofheat-resistant material, with controllable ventilation, and shall

lx

MIL-PRF-83671B

provide a quiet draft-free atmosphere around the specimen. Thechamber design shall permit normal thermal circulation of airpast the specimen during burning. The minimum inner dimensionsshall be600nun x300 mmx75mm(Lx WxH) . A closableopening, for ventilation, approximately 25 mm in diameter, shallbe located in the top of the chamber. Use of a hood with anexhaust system, either around the chamber or as the test chamberitself, is strongly recommended in order to remove the noxiousproducts of combustion. Test results should be the same whetheror not the chamber damper is closed,both .

the hood fan is off, orIn cases of discrepancy, values obtained with the damper

closed or the hood fan off, or both, shall be the valid testresults. The chamber/hood shall have a heat-resistant viewingwindow of sufficient size, and located such that the entirespecimen being tested can be observed. The chamber should beeasily opened and closed to facilitate test activities. The testorganization’s operations and equipment shall be approved by theappropriated environmental and/or safety activity.

b. Burner. A standard Bunsen or Tirrill burner (10 nunoutside diameter barrel) fitted with a 50 nunwide wing top shallbe used. The wing top may have to be opened to approximately3 mm to provide the flame required in Figure 6. Use flexiblemetal hose or adequately protected rubber or plastic hose.

c. Fuel supply - propane gas of at least 85 percent purity.

d. Specimen support - wire cloth (wire screen) 6.5 mm meshusing 0.8 mm diameter steel wire. The wire cloth specimensupport (75 nunx 200 mm) shall have a 15 mm length bent to form aright angle. This will form the specimen support as shown inFigure 5.

e. Specimen support holder - any holding device that willclamp the wire cloth specimen support horizontally so that thebottom of the bent-up portion is 15 nunabove the top of theburner wing top as shown in Figure 5. A typical arrangementconsists of two laboratory ring stands with two adjustable flatsurface clamps which may be locked in place by set screw and locknut .

f. Timing device - readable to A 1 second.

4.3.3.8.2 Test

a. Five specimens, 50 mm x 150 mm x 10 nun, (L x W x H) withparallel orientation shall be prepared as specified in 4.3.1 (seeFigure 4).

b. Material thickness shall be 10 mm ~ 2 mm. Thicknessshall be parallel to the direction of rise.

c. Eachone line 125

test specimen shall be marked across the width withmm from one end.

19

MIL-PRF-83671B

4.3.3 .8.3. . .

Specimens shall be conditioned prior totest for a minimum of 24 hours in accordance with 4.3.2. Testsshall be made in this atmosphere or immediately after removaltherefrom.

4.3.3.8.4 ix.wdum. See Figures 5, 6, and ~.

a. Clamp the wire cloth specimen support horizontally sothat the bottom of the wire cloch is 15 mm above the burner’swing top as shown in Figure 5. Place a layer of aluminum foil onthe bottom of the test chamber to catch any dripping or flamingparticles. The distance between the wire cloth and the foilshall be between 150 mm and 200 mm. Change the foil after eachtest if there is any debris on the surface from che previousdetermination. Burn off any material remaining on the wire clothfrom the previous test or use a new wire cloth for each test. Ifa new wire cloth is not used for each test, the wire cloth shouldbe cool to the touch before being used. If dripping or meltingmaterial falls into the wing top, clean it before testing thenext specimen.

b. Place the specimen on the support with one end touchingthe 15 nun bent-up portion of the support. The end of chespecimen nearest the gage mark should be away from the bent-upend of the specimen support so that the gage mark is 125 mm awayfrom the bent-up end.

Adjust the burner with the wing top co provide a blueflam~”wich a visible portion 40 nunhigh and a clearly definedinner cone 5 mm high. Place the burner under the upturned end ofthe specimen support so that one edge of the flame is in linewith the upturned end of the wire cloth and the other edge of theflame extends into the front end of the specimen.

d. Start the timing device when the flame is first appliedto the specimen. After 60 seconds, move the burner at least 150nunaway from the test specimen. If the flame goes out beforereaching the gage mark, the extent of burning is equal to 125 mmminus the distance from the gage mark to the nearest evidence ofthe flame front, such as charring along the upper surface of thespecimen, measured to the nearest 2 mm. Note burningcharacteristics, such as expansion, as a result of heating,melting, or dripping; also record if the drippings on the foilburn. In some cases, the burning may cease in the first 60seconds. This will be evident by the disappearance of the flame.

4.3.3.8.5

a. If the flame front passes the gage mark on any one of chefive specimens, the lot has failed.

20

MIL-PRF-83671B

b. If the flame front does not reach the gage mark on any ofthe five-specimens, average the distance burned in millimeters asmeasured on the top surface.

4.3.3.8.6 ~. A report in any acceptable format shallinclude the following:

a. The description of the material including the proprietarydesignation and complete description per this specification.

b. A description of samples that burned to gage mark.

(EXAMPLE: 150 mm sample was consumed completely. )

c. Record burning characteristics, such as dripping.

d. For samples that did not burn to the gage mark, reportthe average extent of burning (125 nun - less the distance betweenthe gage mark and closest evidence of burning) .

4.3.3.8.7 The standard deviation for interlaboratory reproducibility is 10 mm.

4.3.3.9 ve strmath. (~ The compressivescrengch shall be determined in accordance with ASTM-D1621,procedure A, and examined for conformance to 3.3.2 and 3.3.9.After a minimum 72-hour cure time, a total of ten specimens100 nunx 100 mm x 50 mm shall be prepared from each of three300 mm x 300 mm x 300 mm single pour blocks of foam. Fivespecimens shall be cut such that the depth dimension of 50 mm isparallel co the direction of foam rise. These specimens shallthen be tested for compressive strength values at yield or 10percenc deflection, whichever occurs first. Additionally, fivespecimens 100 mm x 100 mm x 50 nunshall be cut from each of thesame three sample blocks such that the depth dimension of 50 mmis perpendicular co che direction of foam rise, then tested aswith the initial fifteen specimens. Failure of the averagecompressive strength value, recorded for any set of fivespecimens, to conform to the requirement of 3.3.9 shall be causefor rejection.

4.3.3.10 2

4.3.3.10.1 . Thedata to plot the peak acceleration in multiples of Gs versusstatic stress in Pascals, from a drop height of 0.6 m, shall beestablished in accordance with ASTM-D1596 with exceptionsspecified herein.

4.3.3.10.2 SQXimas. Three specimens, 200 mm x 200 ~ x 75 MM~ 2 mm with parallel orientation shall be prepared as specifiedin 4.3.1 (see Table IV.)

21

MIL-PRF-83671B

4.3.3.10.3 Each specimen shall be compressed to 60percent of its originai thickness in accordance with 4.3.1.6. Aspecimen shall be rested for at least 16 hours, but not more than72 hours before conducting the dynamic test procedure.

4.3.3.10.4 All test samples shall bemeasured to determine that samples are within 10 percent of therequired thickness of 15 nunbefore starting the dynamic testprocedure. Impact tests shall be conducted on each specimen sothat the dropping head compresses the specimen at an initialvelocity at impact of 3.43 m ~ 0.05 m per second. Thiscorresponds to a nominal initial free-fall drop height of 0.6 m.The acceleration-time record of the dropping head duringcompression of the cushion shall be recorded for each drop. Withthe dropping head at the lowest static stress point, fiveconsecutive drops shall be made on each of the specimenscomprising the sample material. At least one minute shall elapsebetween drops to permit the specimen to regain its shape. Aquantity of weight shall then be added to che dropping head toobtain the next required higher static stress point and the droptest procedure repeated. This procedure shall be repeated untilthe qualifying test values have been obtained. No materialsamples will be replaced during the test for any reason. If anyof the cushions are degraded to a point where they can no longerbe impacted, the whole lot shall be rejecced.

4.3.3.10.5 The first reading obtained from eachset of drops shall be discarded, and the peak accelerationreadings of the remaining four drops shall be averaged. Theaverage values, one for each specimen, shall then be averaged toobtain one value at each static stress point for the sample. Therequired peak G-static stress points shall be examined forconformance to 3.3.10.

4.3.3.11 ~ rear- t1=~ The maximum reactiontemperature shall be determined by monitoring the temperaturerise when the mixed chemicals are permitted to expand in a 300 mmx 300 mm x 300 mm corrugated fiberboard container, conforming toASTN-D5118. Polyethylene film, from 0.7 to 2.0 mil in nominalguage, shall line the inside surface of the container. The flapsof the container shall remain open, and the film shall drape overthe sides of the container. A temperature sensor, thermocoupleor thermometer, shall be positioned at the center of theconcainer. A sufficient quantity of mixed chemical componentsshall be poured into the container to expand without restraintand completely fill the container. The temperature shall bemonitored for 2 hours, or until the peak temperature is observed,recorded, and the temperature has subsided by at least 5.5°C.

4.3.3.12 Cstld r~~re stalwb..tv. .

(c~ Five samples,measuring 100 mm x 100 nunx 25 nun (L x W x H), “with perpendicularorientation, shall be prepared as specified in 4.3.1. Specimensshall be tested in accordance with ASTM D2126 at a test

MIL-PRF-83671B

temperature of -40°C ~ 3°C and examined for conformance to therequirements of 3.3.12.

4.3.3.13 ~. ~elve samples shall be prepared asspecified in 4.3.1. Friability shall be determined in accordancewith the tumbling technique of ASTM-C421 with the followingmodification: the drying temperature of ASTT4-C421, paragraph 5.3shall be 104°C to 113°C. Samples shall be examined forconformance to the requirements of 3.3.13.

4.3.3.14 ath (c~ Testing and samplepreparation shall be in accordance with ASTM-D1623. Threesamples each shall be prepared for parallel tests andperpendicular tests. Type A or type B test specimens shall beused. Tensile strengths as determined by testing shall conformco Lhe requirements of 3.3.14.

4.3.3.15 wtur~. .

va~v [~ Three testspecimens, from which the skins have been removed, shall betested. Specimen thickness’ shall be parallel to the directionof foam rise. Tests and sample preparation shall be performed inaccordance with ASTM-E96, using the Desiccant method under thestandard test condition X1.1.1, Procedure A, with the followingexceptions:

a. The thickness of the test sample shall be 75 mm ~ 2 mm.

b. The specimen holder shall have a diameter of 150 mm ~6 mm, and its circular edge shall be used as the cutting dieduring the insertion of the sample. A hydraulic press or similareauiomenc shall be used to force the specimen holder cutting edgethro~gh the entire thickness of

4.3.3.16 ~.

4.3.3.16:1dimensions of 300 nunx 300 mm xshall be trimmed by removing atfour sides, the top, and bottom

che foam sample.

A foam bun having minimum300 mm shall be poured. The bunleast 40 mm of material from allof the bun. The bun shall be cuc

into two pieces at a point 100 mm down from the top; this willresult in a piece 230 mm x 230 mm x 125 mm. From the top of thispiece, a slice measuring 230 mm x 230 mm x 25 mm shall be cut. Acircular die having an inside diameter of 30 mm shall be used forcucting five specimens from the 25 nun thick slice of foam. These30 mm diameter, 25 mm high samples shall be conditioned for atleast 24 hours at 23°C k 1°C and 50 percent RH A 5 Percent RH.

4.3-3.16.2 ~. Four specimens prepared andconditioned in accordance with 4.3.3.16.1 shall be immersed inNo. 2 reference oil of ASTM-D471 at 23°C L 1°C. The fifthspecimen shall remain unused in accordance with the conditionsspecified in 4.3.3.16.1. The test room or chamber shall bemaintained ac SO percent RH + 5 percent RH. After 70 hours ~ 1hour, the specimens shall be removed, lightly blotted and

compared with thedegradation shallthe lot.

5. PACKAGING

MIL-PRF-83671B

unused specimen. Evidence’ of softening orconstitute failure of the samples representing

5.1 For acquisition purposes, the packagingrequirements shall be specified in the concract or order (see6.2). Nhen actual packaging of materials is to be performed byDoD personnel, these personnel need to contact the responsiblepackaging activity to ascertain requisite packaging requirements.Packaging requirements are maintained by the Inventory ControlPoint’s packaging activity within the Military Department,Defense Agency or within the Military Department’s SystemCommand. Packaging data retrieval is available from the managingMilitary Department’s or Defense Agency’s automated packagingfiles, CD-ROM products, or by concocting the responsiblepackaging activity.

6. NOTES

(This section contains information of a general or explanatorynature that may be helpful, but is not mandatory. )

6-1 ~. Materials covered by this specification areintended for use as cushioning and blockinglbracing in packagesto protect equipment and items from damage by shocks or impaccsincurred during shipment and handling.

6.2 ~nn real~. Acquisition documents shouldspecify the following:

a. Title, number, and date of specification.

b. Issue of DODISS to be ciced in the solicitation and, ifrequired, the specific issue of individual documents referenced(see 2.1).

c. Class, grade and category (see 1.2).

d. After 1 Ott 93, provide certified statement that theproduct does not contain CFCS andlor HCFCS (see 3.2).

Hydrolytic stability - specify if noc required (see 3.3.2and ~;6).

f. Maximum allowable percentage creep, if other thanspecified in 3.3.4 (classes 2 and 3) .

Maximum allowable percentage set, if other than asspec;kied in 3.3.5 (classes 2 and 3) .

Pliability (classes 2 and 3) - state if noc required (see3.3.K

24

MIL-PRF-83671B

i. Minimumin 3.3.9 (class

Tensile3.3.:4).

compressive strength, if other than as specified1 - see 6.5).

strength (class 1) - specify if required (see

k. Moisture vaporrequired (see 3.3.15).

1. Oil resistance3.3.16).

permeability (class 1) - specify if

(class 1) - specify if required (see

m. Indicate guaranteed conformance to minimum shelf liferequirements of paragraph 3.4

n. Indicate marking requirements (see 3.5).

Indicate whether first article inspection is waived (see4.2.?;.

P. Packaging requirements (see 5.1).

6.3 .Ei.Esrar~. when first article inspection is required,che contracting officer should provide specific guidance toofferors whether the item(s) should be a preproduction sample, afirst article sample, a first production item, a sample selectedfrom the first production items, a standard production item fromthe contractor’s current inventory (see 3.1), and the number ofitems to be tested as specified in 4.2.2. The contractingofficer should also include specific instructions in acquisitiondocuments regarding arrangements for examinations, approval offirst article test results, and disposition of first articles.Invitations for bid should provide that the Government reservesthe right to waive the requirement for samples for first articleinspection co those bidders offering a product which has beenpreviously acquired or tested by the Government and that biddersoffering such products, who wish to rely on such production ortest, must furnish evidence with the bid that prior Governmentapproval is presently appropriate for the pending contract.Bidders should not submit alternate bids unless specificallyrequested to do so in the solicitation.

6.4 The requirements of 3.3.10 are intendedto ensure procurement of a consistently uniform product of aquality attainable by most of the industry. The curves presentedin Figures 1, 2, and 3 should be considered as quality assurancerequirements only, not as design criteria. For design purposes,complete cushioning data in the form of peak acceleration versusstatic stress curves can be obtained from other sources, such asMIL-HDBK-304 . The acceptable cushioning curves for class 2,grades A and B and class 3 foams are shown in Figures 1, 2, and3, respectively. Class 2, grades A and B and class 3 foams arenot based on specific material densities.

2s

MIL-PRF-83671B

6.5 The compressive strengthrequirements of 3.3.9 were developed from test data obtained on

materials with nominal densities of 0.032 x 103 kg/cm3. If adifferent density material is specified, the compressivestrengths should also be specified. For MIL-HDBK-775, technique

VII encapsulated pack, the 0.032 x 103 kg/cm3 category 2 foam isrequired. It possesses the higher minimum compressive strengths

of 2.00 Kg/cmJ parallel to the direction of rise and 1.00 Kg/cmaperpendicular to the direction of rise.

6.6 Some polyurethane foams, esters inParticular, maY not pass this test but satisfactorily meet allother requirements and, in some instances, have dynamiccushioning properties superior to ocher formulations. Procuringactivities may waive the hydrolytic requirements of 3.3.2.

6.7 MaximuM rpart~. The maximum reactiontemperatures of Table I were based on tests conducted on allclasses and grades of materials. If a higher density material

than 0.032 x 103 kg/cm3 is being procured, the maximum reactiontemperature should be specified by the procuring activity.

6.8 ~. The following terms listed in Table I havethese definitions:

a. Cream time - period between “foam pour” of foam chemicalsand start of foaming action.

b. Rise time - elapsed time between foam pour and mejoricy(95 percent) of foam expansion after pouring.

c. Tack free time - elapsed time between foam pour andperiod when semi-cured foam may be couched lightly withoutstickiness .

6.9 The minimum acceptable shelf life ofthe foam chemical is one year when the storage temperatureremained in the 10°C to 35°C conditioning temperature range. Thenominal freezing point of isocyanates is approximately -6.7°C.Some materials have been usable following prolonged storage inthe -23°C co -12°C range. As a guide, prolonged exposure to ll°Cabove the 35°C maximum normally halves the shelf life. Exposureto temperatures ll°C below the 10°C minimum conditioningtemperature could be expected to double the shelf life. It isimporcanc gor users to allow adequate intervals for temperaturestabilization In the 10°C to 35°C conditioning range.

6.10 ~. volume users maY encounter animbalance of components over an ex:ended period of time due todifferences in viscosity, altitude, metering equipment,applications, etc. If this occurs, the needed componenc (A or B)

MIL-PRF-83671B

may be procured directly from the original supplier by furnishingthe applicable information specified in 3.5.2.

6.11 ~. The Occupational Safetyand Health Administration (OSHA) has promulgated a PermissibleExposure Limit for methylene bisphenyl isocyanate (NDI) (CAS101-68-8) of 20 parts per billion, as a “ceiling” limit which, bydefinition, should not be exceeded at any time during theworkday, even if exposures at other times during the workday arebelow 20 ppb, resulting in an average exposure for the workdaywhich does not exceed 20 ppb.

6.12 ova1 ofInformation regarding dynamic compression testing apparatusapproval can be obtained by contacting AFMC LSOILOPM, 5215Thurlow St, Wright-Patterson Air Force Base, OH 45433-5540.

6.13 Wbiert rem

Polyurethane foamCushioningFlame-resistant foamFI PFoam

6.14 ~-in-Dlare om=~ . An evaluation of aworker’s exposure to toxic chemicals released during foam-in-place operations shall be performed at each work place, utilizingNational Institute for Occupational Safety and Health (NIOSH)recommended sampling and analysis techniques. Thesedeterminations shall be accomplished by persons andlor agencieshaving recognized competence in industrial hygiene, sampling, andanalysis. Inquiries relating to the sampling of foam-in-placeoperations ac Navy and Marine Corps facilities should be directedco che Commanding Officer, (Attn: Industrial HygieneDirectorate) , Navy Environmental Health Center, 2510 WalmerAvenue, Norfolk, VA 23513-2617.

6.15 af=~ fr~ nr~v~. Marginal notations are notused in this revision to identify changes with respect to theprevious issue due to the extensiveness of the changes.

27

MIL-PRF-83671B

110.

100.

80.

z 80.

5 70.r

i

80.

so.

i!40.

30.

20.

Io.

0. L

STATICSIFESS lKg/lc.mx am))

Peak G - Static Stress Curvedrop

sample size -height - 0.6 m200mmx200mmx751mn(see 6.4)

FIGURE 1.

MIL-PRF-83671B

110.

100.

90.

: 80.

3 70. \c \

!

‘.90.

.

so.

i!40. \

\ \ ‘.- -- - ---- ,-----

30.

20.

10.

o:o~o,STATICSITES 1~/[om I om) )

Peak G - Static Stress Curvedrop

sample size -

FIGURE 2.

height - 0.6 m200mmx200nunx75m(see 6.4)

29

MIL-PRF-83671B

110. ,

100.

00.

a 80.

6 70.r

\\ \

i ‘

\80.

\\

50..

.

ii

‘.&o. \

\. . ~.

30. \. - -

20.

10.

0..001 .002 .00s .Oot.005 .007 .01 .02 .03 .04

STATIC.SITESSItQ/(cm x cm) 1

Peak G - Static Stress Curvedrop height - 0.6 m

sample size - 200mmx200mmx751TMx(see 6.4)

FIGURE 3. ~.

30

MIL-PRF-83671B

FIGURE 4. e of

31

MIL-PRF-83671B

.wJ’O~d-D-- glJRNERUnffi TnP

FIGURE 5.. . of

and so~c~.

FIGURE 6.. .

lvf= on..

MIL-PRF-83671B

FIGURE 7. for

33

MIL-PRF-83671B

Custodians: Preparing activity:Army - SMNavy - SA Air Force - 69Air Force - 69DLA - DH (Project 8135-0701)

Review activities:

Army - AL, AT, AV, CR, EA, MD, ME, MI, W?, MTNavy - AS, EC, SH, YD1Air Force - 11, 71, 82, 84, 99DLJA- GS, CC

34

STANDARDIZATION DOCUMENT IMPROVEMENT PROPOSAL

INSTRUCTIONS

1. The preparing activity must complete blocks 1, 2.3. and 8. In block 1, both the document number and revisionletter should be given.

2. The submitter of this form must complete blocks 4, 5,6,and7.

3. The preparing activity must provide a reply wlthln 30 days from receipt of the form.

NOTE: This form may not be used to request copIes of documents, nor to request waivers, or clarification ofrequirements on current contracts. Comments submitted on this form do not constitute or imply authorization towaive any portion of the referenced document(s) or to amend contractual requirements.

I RECOMMEND A CHANGE: ‘“ ~LH~~;.~~~BZ. OOCUMIN1 DAIC (YYMMD2)J

970203OOCUMENT TETLE

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Air Force Packagingb, TELEPHONE (Include Area Code)(1) Commercial (2) AUTOVON

Technology ssndEngineering Facility 937-257-4519 787-4519ADDRESS (Include Zip Cede) IF YOU 00 NOT R[CENE A REPLY WllHIN 45 DAYS. CONTACT:

AFNC LSO/LOP Oefenia Ouality and Standardization Office

5215 Thurlow Street S203 Leehwg Pike. Suite 1a43. Fall! Church. VA 22041.3466

Wright-Patterson AFB OH 45433-5540 Telephone f703) 7S6.23d0 AUTOVON 2S9-2340

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