1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro
2、m, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.Copyright 2001 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.
3、A.QUESTIONS REGARDING THIS DOCUMENT: (724) 772-7161 FAX: (724) 776-0243TO PLACE A DOCUMENT ORDER: (724) 776-4970 FAX: (724) 776-0790SAE WEB ADDRESS: http:/www.sae.org400 Commonwealth Drive, Warrendale, PA 15096-0001AEROSPACE MATERIAL SPECIFICATIONAMS 3787AIssued APR 1986 Revised APR 1991Reaffirmed J
4、AN 2001Superseding AMS 3787Thread, Para-AramidIntermediate Modulus1. SCOPE:1.1 Form: This specification and its supplementary detail specifications cover para-aramid materials in the form of thread.1.2 Application: Primarily for use in sewing clothing, equipage, and air delivery and safety equipment
5、.1.3 Classification: The requirements specified herein and in the applicable detail specifications define each type of thread by length per unit weight and breaking strength as shown in the detail specification titles.1.4 Safety - Hazardous Materials: While the materials, methods, applications, and
6、processes described or referenced in this specification may involve the use of hazardous materials, this specification does not address the hazards which may be involved in such use. It is the sole responsibility of the user to ensure familiarity with the safe and proper use of any hazardous materia
7、ls and to take necessary precautionary measures to ensure the health and safety of all personnel involved.2. APPLICABLE DOCUMENTS: The following publications form a part of this specification to the extent specified herein. The applicable issue of referenced publications shall be the issue in effect
8、 on the date of the purchase order.Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-AMS 3787A SAE AMS 3787A- 2 -2.1 ASTM Publications: Available from ASTM, 1916 Race Street, Philadelphia, PA 19103-1187.
9、ASTM D 123 Terminology Relating to TextilesASTM D 1788 Rigid Acrylonitrile-Butadiene-Styrene (ABS) PlasticsASTM D 4101 Propylene Plastic Injection and Extrusion Materials2.2 U.S. Government Publications: Available from Standardization Documents Order Desk, Building 4D, 700 Robbins Avenue, Philadelph
10、ia, PA 19111-5094.2.2.1 Federal Specifications: PPP-P-50 Packaging and Packing of Thread for Domestic and Overseas Shipment2.2.2 Federal Standards: FED-STD-191 Textile Test Methods2.2.3 Military Standards: MIL-STD-105 Sampling Procedures and Tables for Inspection by Attributes3. TECHNICAL REQUIREMEN
11、TS: 3.1 Detail Specification: The requirements for a specific thread shall consist of all requirements specified herein in addition to requirements specified in the applicable detail specification. In case of conflict between requirements of this specification and requirements of the applicable deta
12、il specification, requirements of the detail specification shall govern.3.2 Material: 3.2.1 The yarn used in the thread shall be a para-aramid, intermediate modulus type.3.2.2 Thread Finish: Thread shall be waxed or finished so that it will have a smooth, dressed surface suitable for high-speed mach
13、ine sewing. For additional structural integrity, 0.5 to 1.0% by weight of a resinous finish, such as polyvinyl butyral, may be applied.3.3 Properties: Thread shall conform to the requirements specified in the applicable detail specification, determined on the thread supplied and in accordance with t
14、he following test methods:Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-AMS 3787A SAE AMS 3787A- 3 -3.3.1 Weight: FED-STD-191, Method 4010.3.3.2 Breaking Strength: FED-STD-191, Method 4100. One deter
15、mination per sample unit; report result as “pass” or “fail”.3.3.3 Direction of Twist; Initial and Final: FED-STD-191, Method 4050.3.3.4 Number of Plies and Composition of Plastic Tubes: A vendors certificate of conformance shall be acceptable for determining conformance to these requirements.3.3.5 F
16、inish: Visual inspection.3.3.6 Twist; Turns per Unit Length: 4.5.1.3.4 Quality: Thread, as received by purchaser, shall be free from foreign materials and from imperfections detrimental to usage of the thread.4. QUALITY ASSURANCE PROVISIONS: 4.1 Responsibility for Inspection: The vendor of thread sh
17、all supply all samples for vendors tests and shall be responsible for performing all required tests. Purchaser reserves the right to sample and to perform any confirmatory testing deemed necessary to ensure that the thread conforms to the requirements of this specification and the applicable detail
18、specification.4.2 Classification of Tests: 4.2.1 Acceptance Tests: Tests for the following requirements are acceptance tests and shall be performed on each lot of thread:4.2.2 Preproduction Tests: Tests for all technical requirements are preproduction tests and shall be performed prior to or on the
19、initial shipment of thread to a purchaser, when a change in ingredients and/or processing requires reapproval as in 4.4.2, and when purchaser deems confirmatory testing to be required.Requirement Paragraph ReferenceLength per Unit Weight See Detail SpecificationBreaking Strength See Detail Specifica
20、tionQuality 3.4Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-AMS 3787A SAE AMS 3787A- 4 -4.2.2.1 For direct U.S. Military procurement, substantiating test data and, when requested, preproduction test
21、 material shall be submitted to the cognizant agency as directed by the procuring activity, contracting officer, or request for procurement.4.3 Sampling and Testing: Shall be as follows4.3.1 For Acceptance Tests: Sufficient thread shall be taken at random from each lot to perform all required tests.
22、 The number of determinations for each requirement shall be as specified in the applicable test procedure or, if not specified therein, not less than three.4.3.1.1 A lot shall be all thread of a single weight produced in a single production run under the same fixed conditions and presented for vendo
23、rs inspection at one time. A lot may be packaged in small quantities and delivered under the basic lot approval provided lot identification is maintained.4.3.1.2 The sample unit shall be one holder or sufficient holders to provide enough thread for the required tests. The lot size shall be expressed
24、 in units of one holder, or gross of ready-wound bobbins. The inspection level shall be MIL-STD-105, Level S-1.4.3.1.3 Visual Examination: Refer to ASTM D 123 for definitions of terms used herein. The term “clearly visible” used in Table I shall mean visible at normal inspection distance of approxim
25、ately 3 feet (1 m).4.3.1.3.1 Thread on Holder: The thread shall be examined on the holder and the imperfections listed in Table I counted. The sample unit shall be one holder except that for ready-made bobbins the sample unit shall be one gross. The lot size shall be expressed in units of one holder
26、 except that for ready-made bobbins the lot size shall be expressed in units of one gross. The inspection level shall be MIL-STD-105, level S-3.4.3.1.3.2 Thread as Wound: The thread shall be examined by unwinding and imperfections listed in Table I shall be counted regardless of their proximity to e
27、ach other. Sample unit and lot size shall be as in 4.3.1.3.1.Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-AMS 3787A SAE AMS 3787A- 5 -4.3.1.3.3 Net Weight per Holder: The sample unit shall be 10 wou
28、nd holders, taken at random from the lot. Sample size shall be one sample unit regardless of lot size. Holders shall be weighed individually and the net weight of the thread determined. The values obtained shall be averaged, and this average shall represent the net weight of thread per holder in the
29、 lot. The lot shall be unacceptable if the net weight of thread per holder is less than the specified weight, minus a 3% tolerance.4.3.1.4 When a statistical sampling plan has been agreed upon by purchaser and vendor, sampling shall be in accordance with such plan in lieu of sampling as in 4.3.1, an
30、d the report of 4.6 shall state that such plan was used.TABLE ITHREAD IMPERFECTIONSRequirement Imperfections on HoldersIdentification label Missing, incorrect, incomplete,illegible, or insecurely attachedType of holder Other than specifiedSurface condition Cut, tear, chafe, or slipaffecting strength
31、 of thread orinterfering with easy location ofend and initial unwindingCleanliness Dirt, spot, or stain clearlyvisibleFinish Not in continuous lengthsKnot Size FF and finer thread shallaverage not more than one threadknot per 2 ounces (57 g); size 3and heavier thread shall averagenot more than 1 thr
32、ead knot per4 ounces (113 g).Winding Improperly or not firmly wound,resulting in kinks, knots,entangling, or slippage duringunwinding, or otherwise affectingunwinding of the thread.Tackiness or adhesion The strands adhere to each otheror to holder, affecting unwindingtension.Copyright SAE Internatio
33、nal Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-AMS 3787A SAE AMS 3787A- 6 -4.3.2 For Preproduction Tests: As agreed upon by purchaser and vendor.4.4 Approval: 4.4.1 Sample thread shall be approved by purchaser before thread
34、for production use is supplied, unless such approval be waived by purchaser. Results of tests on production thread shall be essentially equivalent to those on the approved sample thread.4.4.2 Vendor shall use ingredients, manufacturing procedures, processes, and methods of inspection on production t
35、hread which are essentially the same as those used on the approved sample thread. If necessary to make any change in ingredients, in type of equipment for processing, or in manufacturing procedures, vendor shall submit for reapproval a statement of the proposed changes in ingredients and/or processi
36、ng and, when requested, sample thread. Production thread made by the revised procedure shall not be shipped prior to receipt of reapproval.4.5 Test Methods: Shall be in accordance with the following:4.5.1 Twist Testing: Determination of twists per inch (25.4 mm) in the individual cords (strands) sha
37、ll be in accordance with FED-STD-191, Method 4052, and shall be performed in conjunction with the determination for final twist. After recording the final twist value and while the individual cords (strands) are straight between the jaws, all cords (strands) but one shall be cut out and removed. The
38、 clamp shall then be opened, the slack drawn through, and the cord (strand) reset under the specified tension. The jaw shall then be rotated until all twist has been removed, as determined by free passage of the needle between the filaments. The twists per inch (25.4 mm) shall be calculated followin
39、g FED-STD-191, Method 4054. Capstan or drum type clamps shall be used. Five determinations shall be made per sample unit.4.6 Reports: The vendor of thread shall furnish with each shipment a report showing the results of tests to determine conformance to the acceptance test requirements and stating t
40、hat the thread conforms to the other technical requirements. This report shall include the purchase order number, lot number, AMS3787A and the applicable detail specification number and their revision letters if any, vendors thread designation, specified thread weight, and quantity.4.7 Resampling an
41、d Retesting: If any specimen used in the above tests fails to meet the specified requirements, disposition of the thread may be based on the results of testing three additional specimens for each original nonconforming specimen. Failure of any retest specimen to meet the specified requirements shall
42、 be cause for rejection of the thread represented. Results of all tests shall be reported.Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-AMS 3787A SAE AMS 3787A- 7 -5. PREPARATION FOR DELIVERY: 5.1 Pa
43、ckaging and Identification: 5.1.1 Put-up: Thread shall be put up on a nominal weight per holder basis on commercial straight paper tubes, single-head plastic tubes, single head wooden spools, or skeins (hereinafter referred to as holders) as specified by purchaser in accordance with Table II. When p
44、ut-up on ready-made lockstitch bobbins is specified, the style of bobbin and the length of thread thereon shall be as specified by purchaser. The average weight per holder shall be not less than the specified weight minus a 3.0% tolerance, determined on a 10 holder basis. The thread shall be put up
45、in one continuous length per holder and shall be so wound that each turn and layer is free from entanglement.5.1.1.1 Plastic Tubes: Shall be single-head plastic tubes and shall be made from either acrylonitrile or polypropylene conforming to the following requirements:5.1.1.1.1 Acrylonitrile: Tubes
46、shall be acrylonitrile-butadiene-styrene (ABS) rigid plastic conforming to ASTM D 1788, Type A, grade 3, and the following:Tensile Yield Stress, minimum 8 ksi ( 55 MPa)Modulus of Elasticity in Tension, minimum 400 ksi (2758 MPa)Rockwell Hardness (R Scale), minimum 105Specific Gravity, 23/23C (73/73F
47、), maximum 1.2 Chemical Resistance to 40-hour immersionin heptane at 23C 2 (73F 4),weight change, maximum 5%TABLE IIPUT-UPLetter orNumber Size Type of Holder Net WeightAll letter sizes Single wood spools 1 ounce (28 g)All letter sizes andnumber sizes 3, 5, and,when specified, 6Single head plastic 4,
48、 8, or 16 ounces(113, 227, or454 g)Number sizes 6 and 8;sizes 3 and 5 whenspecifiedStraight paper tubes 8 or 16 ounces(227 or 454 g)All letter sizes Skein 1 ounce (28 g)Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without lic
49、ense from IHS-,-AMS 3787A SAE AMS 3787A- 8 -5.1.1.1.2 Polypropylene: The tubes shall be molded from a virgin polypropylene homopolymer conform to ASTM D 4101.5.1.2 Each holder shall have a durable label or tag legibly marked with not less than the following information and attached so as to remain in place until all thread has been removed from the holder:THREAD, PARA-ARAMIDAMS 3787A*LENGTH PER POUND (kg) _
