1、 INCH-POUNDS MIL-DTL-25421C 23 January 2009 SUPERSEDING MIL-P-25421B 18 January 1971 MILITARY SPECIFICATION PLASTIC MATERIALS, GLASS FIBER-EPOXY RESIN, LOW PRESSURE LAMINATED This document is inactive for new design. This specification is approved for use by all Departments and Agencies of the Depar
2、tment of Defense. 1. SCOPE 1.1 Scope. This specification covers the requirements for glass fiber base, epoxy resin low pressure laminated plastic materials. The materials may be furnished as sheets or formed parts, as specified. 1.2 Classification. The glass fiber base, epoxy resin low pressure lami
3、nated plastic materials should be of the following types and classes, as specified (6.2): Type I General Purpose Type II Heat Resistant Class 1 Nonelectrical Class 2 Radio Frequency Class 3 Radar Requency 1.2.1 Glass base identification. The laminated materials should be further identified by cloth
4、number or mat description of the component glass fiber base as shown in Tables I and II; e.g. “Type I, Class 1 laminate, cloth base number 112.” Comments, suggestions, or questions on this document should be addressed to: Commander, U.S. Army Research, Development and Engineering Center, ATTN: AMSRD
5、-AMR-SE-TD, Redstone Arsenal, AL 35898-5000. Since contact information can change, you may want to verify the currency of this address information using the ASSIST Online database at HTTP/:assist.daps.dla.mil. AMSC N/A FSC 9330 DISTRIBUTION STATEMENT A. Approved for public release; distribution is u
6、nlimited. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25421C 2 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are specified in sections 3, 4, or 5 of this specification. This section does not include documents c
7、ited in other sections of this specification or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requirements of documents cited in sections 3, 4, or 5 of th
8、is specification, whether or not they are listed. 2.2 Government documents. 2.2.1 Specifications, standards, and handbooks. The following specifications standards, and handbooks form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are
9、 those cited in the solicitation or contract. DEPARTMENT OF DEFENSE SPECIFICATIONS PPP-B-585 Boxes, Wood, Wirebound MIL-R-9300 Resin, Epoxy, Low Pressure Laminating MIL-P-9400 Plastic Laminate and Sandwich Construction Parts and Assembly, Aircraft Structural, Process Specification Requirements MIL-M
10、-43248 Mats, Reinforcing, Glass Fiber DEPARTMENT OF DEFENSE STANDARDS MIL-STD-129 Marking for Shipment and Storage MIL-STD-2073-1 Standard Practice for Military Packaging MIL-STD-1916 Department of Defense Preferred Methods for Acceptance of Product (Copies of these documents are available online at
11、 http:/assist.daps.dla.mil/quicksearch/.) 2.3 Non-Government publications. The following documents form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. AMERICAN NATIONAL STANDARDS INSTI
12、TUTE (ANSI) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25421C 3 ANSI/ASQ Z1.4 Sampling Procedures and Tables for Inspection by Attributes (Copies of this document can be obtained from ASQ Distribution Center, 5131 S. Third Street, Milwau
13、kee, Wisconsin, 53207-6028 or www.asq.org.) AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM), International ASTM D1974 Standard Practice for Methods of Closing, Sealing, and Reinforcing Fiberboard Boxes ASTM D2240 Standard Test Method for Rubber Property Durometer Hardness ASTM D6251 Standard Speci
14、fication for Wood-Cleated Panelboard Shipping Boxes ASTM D6880 Standard Specification for Wood Boxes (Copies of these documents can be obtained from the American Society for Testing Material, 100 Bar Harbor Drive, West Conshohocken, PA 19428-2959, or www.astm.org .) SOCIETY OF AUTOMOTIVE ENGINEERS (
15、SAE), International SAE-AMS-C-9084 Cloth, Glass, Finished, for Resin Laminates (Copies of this document can be obtained from 400 Commonwealth Drive, Warren, PA 15096-0001, or http/:www.sae.org/.) 2.4 Order of precedence. Unless otherwise noted herein or in the contract, in the event of a conflict be
16、tween the text of this document and the references cited herein (except for related specification sheets), the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 Prec
17、edence of requirements. The products furnished under this specification shall be as specified herein and in accordance with the drawings, specification, or contract requirements for the specific sheet or part. In the event of discrepancy between this specification and the requirements of the applica
18、ble drawings, specifications, or contract for the specific sheet or part, the requirements of the latter shall govern. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25421C 4 3.2 First article approval. Unless otherwise specified in the cont
19、ract or order (6.2), the laminated plastic materials furnished under this specification shall be products which have been approved under the first article inspection prescribed herein (4.3). 3.3 Materials. Materials used in the laminates shall be as follows: 3.3.1 Glass fiber base. 3.3.1.1 Cloth. Th
20、e cloth shall be continuous filament glass cloth in accordance with Tables I and II and the requirements of SAE AMS-C-9084. 3.3.1.2 Mat, short fibers. The short fiber mat shall conform to the requirements of MIL-M-43248, Grade A. 3.3.1.3 Mat, nonwoven continuous filament. The nonwoven continuous fil
21、ament mat shall be as described in Tables I and II. 3.3.2 Resin. The laminating resin shall conform to the requirements of MIL-R-9300. Types I and II resin of MIL-R-9300 shall be used for Types I and II, laminated material, respectively, of MIL-P-25421. Any electrical or nonelectrical grade of resin
22、 under MIL-R-9300 may be used for any class of laminated material of MIL-P-25421, provided the finished laminate product conforms to the requirements for the applicable class and type under MIL-P-25421 and the requirements for the specific part or end item. 3.3.3 Fillers. Finely divided, inert, inor
23、ganic fillers may be used in mat laminates only, provided other applicable requirements of this specification are met by the laminates. 3.4 Finished product. The finished laminated product shall conform to the following requirements: 3.4.1 Physical properties. The minimum Barcol hardness value and t
24、he minimum and maximum values for specific gravity and for resin content of the laminated materials shall be as specified in the process specification or data sheet. 3.4.2 Mechanical properties. The mechanical properties of the laminated materials shall conform to the requirements of Tables I and II
25、 when tested in accordance with Table VI. 3.4.3 Electrical properties. Except as may be specified otherwise for Class 3 in contract or order (6.2, 6.3), the electrical properties of Class 2 and Class 3 laminated materials shall conform to Table III when tested in accordance with Table VI. There shal
26、l be no electrical requirements for Class 1 material. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25421C 5 TABLE I. Longitudinal 1/ Mechanical Properties of Epoxy Laminates (Types I and II) at Standard Temperature (23C) Glass Fiber Base C
27、loth number 2/ Tensile Strength Thousands of psi (Minimum Average) Compression Strength Thousands of psi (Minimum Average) Flexural Strength (Ultimate) Thousands of psi (Minimum Average) Flexural Modulus of Elasticity (Initial) Millions of psi (Minimum Average) (Parallel Laminated) Standard Conditio
28、ns 3/ Wet Conditions Standard Conditions 3/ Wet Conditions Standard Conditions 3/ Wet Conditions Standard Conditions 3/ Wet Conditions (I) 112 47 45 47 42 70 65 3.3 3.2 (IA) 112-150 47 45 47 42 70 65 3.3 3.2(II) 116 47 45 43 39 63 58 3.3 3.2(IIA) 116-150 47 45 43 39 63 58 3.3 3.2(III) 120 47 45 47 4
29、2 70 65 3.3 3.2(IV) 128 47 45 33 30 63 58 3.3 3.2(IVA) 128-150 47 45 33 30 63 58 3.3 3.2(IVB) 128-750 47 45 33 30 63 58 3.3 3.2(V) 143 90 85 68 60 115 110 5.2 5.0 (VA) 143-150 90 85 68 60 115 110 5.2 5.0 (VI) 162 47 45 23 20 49 45 2.8 2.6 (VII) 164 39 35 31 28 49 45 2.8 2.6 (VIIA) 164-150 39 35 31 2
30、8 49 45 2.8 2.6 (VIII) 181 48 45 50 45 75 65 3.2 3.2(VIIIA) 181-150 48 45 50 45 75 65 3.2 3.2(VIIIB) 181-750 48 45 50 45 75 65 3.2 3.2(IX) 182 50 47 46 41 70 65 3.3 3.2(IXA) 182-150 50 47 46 41 70 65 3.3 3.2(X) 183 50 47 43 39 63 58 3.3 3.2(XI) 184 50 47 37 33 63 58 3.3 3.2(XIA) 184-150 50 47 37 33
31、63 58 3.3 3.2 Mat, short fibers (Random laminated) 25 23 30 25 35 30 1.7 1.5 Mat, nonwoven continuous filament Laminated as specified Crossplied 60 55 55 50 100 85 3.3 3.2 Isotropic 40 35 45 40 65 58 2.5 2.5 Unidirectional 100 90 70 62 125 110 5.0 5.0 1/ Except that volume for random laminated and i
32、sotropic laminated materials are for random oriented specimens and values for crossplied laminates are for specimens cut in the stronger principal direction. By “longitudinal” is meant the warp directions of the parallel laminated cloth base or filament direction of the unidirectional mat base. 2/ A
33、rabic numerals show the base cloth identification numbers under this specification. Parenthetical Roman numerals show, for information only, the cloth type designations under SAE AMS-C-9084. 3/ Dimensional measurements for the determination of mechanical properties under wet conditions are taken bef
34、ore immersion. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25421C 6 TABLE II. Longitudinal 1/ Mechanical Properties of Epoxy Laminates at Elevated Temperatures Glass Fiber Base Cloth number 2/ Types I and II At 70C after hour at 70C TYPE
35、II At 260C after hour at 260 C TYPE II At 260C after 192 hours at 260 C (Parallel Laminated) Flexural Strength (Ultimate) (Thousands of psi) (Minimum Average) Flexural modulus of elasticity (Initial) (Millions of psi) (Minimum Average) Tensile Strength (Thousands of psi) (Minimum Average) Compres-si
36、ve Strength (Thousands of psi) (Minimum Average) Flexural Strength (Ultimate)(Thousands of psi) (Minimum Average) Flexural modulus of elasticity (Initial) (Millions of psi) (Minimum Average) Flexural Strength (Ultimate) (Thousands of psi) (Minimum Average) Flexural modulus of elasticity (Initial) (M
37、illions of psi) (Minimum Average) (I) 112 65.0 3.2 20.0 10.0 22.0 2.0 18.0 1.8 (IA) 112-150 65.0 3.2 20.0 10.0 22.0 2.0 18.0 1.8 (II) 116 58.0 3.2 20.0 8.0 20.0 2.0 15.0 1.8 (IIA) 116-150 58.0 3.2 20.0 8.0 20.0 2.0 15.0 1.8 (III) 120 65.0 3.2 20.0 10.0 22.0 2.0 18.0 1.8 (IV) 128 58.0 3.2 20.0 8.0 20
38、.0 2.0 15.0 1.8 (IVA) 128-150 58.0 3.2 20.0 8.0 20.0 2.0 15.0 1.8 (IVB) 128-750 58.0 3.2 20.0 8.0 20.0 2.0 15.0 1.8 (V) 143 105.0 5.0 42.0 16.0 40.0 3.3 29.0 2.8 (VA) 143-150 105.0 5.0 42.0 16.0 40.0 3.3 29.0 2.8 (VI) 162 45.0 2.8 20.0 6.0 15.0 2.0 11.0 1.4 (VII) 164 45.0 2.8 20.0 6.0 15.0 2.0 11.0
39、1.4 (VIIA) 164-150 45.0 2.8 20.0 6.0 15.0 2.0 11.0 1.4 (VIII) 181 65.0 3.2 45.0 10.0 25.0 2.3 20.0 1.9 (VIIIA) 181-150 65.0 3.2 45.0 10.0 25.0 2.3 20.0 1.9 (VIIIB) 181-750 65.0 3.2 45.0 10.0 25.0 2.3 20.0 1.9 (IX) 182 65.0 3.2 21.0 10.0 22.0 2.0 18.0 1.8 (IXA) 182-150 65.0 3.2 21.0 10.0 22.0 2.0 18.
40、0 1.8(X) 183 58.0 3.2 21.0 8.0 20.0 2.0 15.0 1.8(XI) 184 58.0 3.2 21.0 8.0 20.0 2.0 15.0 1.8(XIA) 184-150 58.0 3.2 21.0 8.0 20.0 2.0 15.0 1.8 Mat, short fibers (Random laminated) 32.0 1.6 12.0 8.0 11.0 1.0 8.5 0.85 Mat, nonwoven continuous filament Laminated as specified Crossplied 80.0 3.0 28.0 11.
41、0 31.0 2.0 25.5 1.8 Isotropic 60.0 2.2 17.0 9.0 20.0 1.5 16.0 1.4 Unidirectional 100.0 4.5 42.5 15.0 39.0 3.0 32.0 2.6 1/ Except that volume for random laminated and isotropic laminated materials are for random oriented specimens and values for crossplied laminates are for specimens cut in the stron
42、ger principal direction. By “longitudinal” is meant the warp directions of the parallel laminated cloth base or filament direction of the unidirectional mat base. 2/ Arabic numerals show the base cloth identification numbers under this specification. Parenthetical Roman numerals show, for informatio
43、n only, the cloth type designations under SAE AMS-C-9084. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25421C 7 TABLE III. Electrical Requirements for Classes 2 and 3 Laminated Materials (see also 6.3) Characteristic Standard Conditions Im
44、mersion Conditions Class 2 (At 1 megacycle) Dielectric contstant (max) 4.4 4.6 Loss tangent (max) 0.045 0.055 Class 3 (At 8,500 to 10,000 megacycles) 1/ Dielectric contstant (max) 4.6 4.6 Loss tangent (max) 0.020 0.025 1/ “X-band” frequency range. The recommended test frequency for this band is 9,37
45、5 megacycles per second (6.3). 3.4.4 Shape, dimensions, and make-up of laminate. The shape, thickness, and surface dimensions of the laminate, the number of component plies of glass cloth or mat in the laminate, the position and direction of the plies, and other specific details of the laminate part
46、s or end items shall be as specified herein and in the drawings or specifications for the part or end item (3.1). Dimensional tolerances shall be as shown in Table V. 3.4.4.1 Gaps or laps in fabric plies. There shall be no gaps between pieces of glass fabric in any lamination. When laps are necessar
47、y, they shall be laid up with a lap width of at least inch. No two laps shall be superimposed upon each other in the plastic. 3.4.4.2 Resin overlays. The laminated plastic materials shall not be made with a gel resin overlay, integrally molded or otherwise, or with any other such thick-resin surface
48、 or surfacing material. 3.4.5 Foreign materials. No metal staples, paper tape, fillers (except in mat laminates (3.3.3), or other foreign materials shall remain in the finished plastic laminate, unless permitted by the applicable drawings or specifications. Parts to which rain-erosion resistant coat
49、ings or other coatings are subsequently to be applied, shall be cleaned free of surface contamination, such as parting agents, which might adversely affect the adhesion of the coating. 3.4.6 Workmanship. The plastic material shall be uniform, smooth, and free from uncured or unbounded areas, gaps, cracks, holes, blisters, resin pockets, areas lacking resin, tackiness, excess surface resin, inc
