ARMY MIL-P-60312C-1975 PARTS MOLDED PLASTIC FOAM POLYSTYRENE (FOR USE WITH AMMUNITION)《聚苯乙烯塑料成型模塑零件(弹药通途)》.pdf

1、- MIL-P-60312C 81 m 777970b 0288026 I/ -06-2l MIL-P-60312C (PA) 5 June 1975 SUPERSEDING 30 November i970 MIL-P-60312B (MU) MILITARY SPECIFICATION PARTS, MOLDED, PLASTIC FOAM, POLYSTYRENE (FOR USE WITH AMMUNITION) This specification is approved for use by all Departments and Agencies of the Departmen

2、t of Defense. 1. SCOPE 1.1 SCOPE. - This specification covers two types of parts molded from universally antistatic polystyrene foam plastic (expanded bead type) and used in packaging and shipping containers for ammunition items (see 6.1 and .6.13). 1.2 CLASSIFICATION 1.2.1 specified. The molded par

3、ts shall be of the following types and classes as Type I - Colored Class 1 - Non-modified Type II - Natural Unpigmented Class 1 - Non-modified Class 2 - Modified (see 6.15) 2. APPLICABLE DOCUMENTS 2.1 The following documents of the issue in effect on date of invitation for bids or request for propos

4、al form a part of this specification to the extent specified herein. SPECIFICATIONS MILITARY MIL-A-48078 - Ammunition, Standard Quality Assurance . Provisions, General Specification for. STANDARDS FEDEFAL FED-STD-595 - Colors. FSC: 8140 THIS DOCUMENT CONTAINS Ir PAGES. ! /- L-; Provided by IHSNot fo

5、r ResaleNo reproduction or networking permitted without license from IHS-,-,-RIL-P-603LZC 81 99979Ob 0288027 b -1 MIL-P-60312C (PA) STANDARDS MILITARY MIL-STD-105 - Sampling Procedures and MIL-STD-1169 - Packaging, Packing and Tables for Inspection by Attributes . Marking for Shipment of Inert Ammun

6、ition Components. (Copies of specifications, standards, drawings, and publica- tions required by suppliers in connection with specific procurement functions should be obtained from the procuring activity or as directed by the contracting officer). 2.2 Other publications. - The following documents fo

7、rm a part of this specikication to the extent specified hetein. Unless otherwise indicated, the issue in effect on date of invitation for bids shall apply. AMERICAN SOCIETY FOR TESTING AND MATERIALS ASTM-D1692-74 ASTM-D2044 - Flammability of Plastic Sheeting - Moisture Content in Paper and (Applicat

8、ions for copies should be addressed to the American Society for Testing and Materials, 1916 Race Street, Phila- delphia, Pennsylvania, 19103). and Cellular Plastics. Paperboard by Toluene Distillation. 3. REQUIREMENTS 3.1 Material. - The foamed plastic parts shall be molded from expandable polystyre

9、ne bead material by the application of heat in a closed mold. 3.2 Dimensions and tolerances. - The dimensions ana tolerances of the mlded parts shall be in accordance with the applicable drawing, specification, contract or purchase order. Draft angles, not exceeding 2 degrees, will be per- mitted if

10、 required to facilitate removal of the parts from the mold. No grease or oil shall be used for mld release purposes. Teflon is suggested. - I I 4 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4 I . MIL-P-603LZC 81 7777706 0288028 8 II MIL-P-60312

11、C (PA) 3.3 Color (Type I only) - The color of the molded parts shall be green, unless otherwise specified by the procuring activity (see 6.2). The green color shall be that of color number 34373, of FED-STD-595, or a darker green than that number when examined by visual means in accordance with 4.5.

12、2. (Color variation or mottling of the color is acceptable pro- vided the lightest portion meets the stated color require- ments). 3.4 Densit . - The molded plastic parts shall have the densities F as applicable) as stated in Table I, when tested in accordance with 4.5.3. TABLE I Density (Nominal) M

13、inimum (1) 0.8 1.7 2.6 3;5 4.3 5.3 ( 1 ) Unte44 othekwih e Apecidied on component dtrawing . 3.5 Moisture content. - Moisture content of the molded part, at time or packing, shall not exceed 0.4.percent when tested in accordance with 4.5.4 (see 6.3). 3.6 Anti-static surface coatinq. - Unless otherwi

14、se specified in the applicable drawings, contract or purchase order, all surfaces of the molded components, prior to dry- ing, shall be coated by dipping only, with an approved anti- static agent (see 6.4). 3.7 Static potential. - The static potential of the components shall be 600 volts maximum, wh

15、en tested in accord- ance with 4.5.5. The test shall be performed after drying the component to the specified moisture control (see 6.5) 3.8 Resistance to surface blocking. - Anti-static coated parts shall be tested for resistance to surface blocking in accordance with 4.5.6. The tested assemblies s

16、hall separate immediately, under their own weight, when the uppermost part in each is lifted. In addition, such separation shall not result in rupture or transfer of such surface coating as determined by visual or other means specified. 3 Provided by IHSNot for ResaleNo reproduction or networking pe

17、rmitted without license from IHS-,-,-MIL-P-60312C 1 779770b 0288029 T mi MIL-P-60312C (PA) 3.9 Integrity of structure. - The fusion of the beads, within the part, shall be demonstrated by the separation of a maximum of twelve (12) beads per 100 square inches, when tested in accordance with 4.5.7. ap

18、ply except where the part drawing calls for a change to either the number of beads or the surface area. This requirement shall 3.10 Self-extinguishing property (Type II, Class 2 only) - Molded parts, known to comply with the moisture content specified shall be tested for a self- extinguishing proper

19、ty. guishing property if it burns upon exposure to flame but does not burn past the gage mark as described in paragraph 7.5 of ASTM-D1692-74, drop emitted by burning shall cause ignition, for more than 10 seconds of the specimen (positioned 12 inches below the test sample) when tested as specified i

20、n 4.5.8. A molded part shall be considered to have a self extin- . Additionally, no 3.11 Molded marking on parts. - Each molded part shall have molded thereon, the molders trademark and Government part or drawing number, and other markings that are required by the applicable contract, specification

21、or drawing. 3.12 Workmanship. - Molded parts shall be free of grease, dirt or other foreign matter. They shall be essentially smooth, free of-r-idges, grooves and other defects. shing operations, or sink marks are acceptable provided that .serviceability is not affected. voids that might affect thei

22、r performance or intended use. Occasional minor marks from knockout pins, steam ports, fini- The.surfaces shall be uniform in compos5tion and free of holes or 3.13 First article inspection. - This specification makes provisions for first article inspection. Requirements for the submission of first a

23、rticle samples by the contractor shall be as specified in the contract. 4. QUALITY ASSURANCE PROVISIONS b.1 Responsibility for inspection and standard quality assurance provisions.- Unless otherwise specified herein or in the contract, the provisions of MIL-A- 48078 shall apply and are hereby made a

24、 part of this detail specification. 4.2 Classification of inspections. - The following types of inspection shall be conducted on this item: a. First Article Inspection (see 4.3). b. c. Packaging Inspection (see 5). Quality Conformance Inspection (see 4.4 ) . 4 I I Provided by IHSNot for ResaleNo rep

25、roduction or networking permitted without license from IHS-,-,-. MIL-P-60 31 2C (PA) 4.3 First article inspection. 4.3.1 Submission. - The contractor shall submit a first article sample (see 6.2e) as designated by the Contracting Officer for evaluation in accordance with provisions of 4.3.2. All mat

26、erials shall be obtained from the same sources of supply as will be used in regular production. The first article sample, which has been produced by the contractor using the same production processes, procedures and equipment as will be used in fulfilling the contract shall consist of: a. Ten consec

27、utively produced parts from each cavity (1). b. Five representative samples selected for moisture determination and prepared for shipment in accord- ance with the provisions of paragraph 4.4.3.1 (2). c. Twelve test specimens (containing skin and anti- static coating, each measuring 6 x 12 x 1/2 inch

28、 (+) - 1/8 inch (3) . 4.3.2 Inspections to be performed. - See MIL-A-48078. 4.3.3 Rejection. - See MIL-A-48078. 4.4 Quality conformance inspection. 4.4.1 Inspection lot formation. - Inspection lots shall comDlv with the lot formation provisions of MIL-A-48078. 4 . 4 . 2 4.4.2.1 Sampling for examinat

29、ion, - Sampling for exam- ination shall be in accordance with the follwing when exam- ining for the defects specified in Table II. Examination. 4.4.2.1.1 A sample of 10 molded parts shall be selected at random from each lot. If three or more parts fail to com- ply with the applicable requirements, t

30、he lot shall be rejected. When the dihhX anticle hamptiat. equat. . Place an established quantity of dry 8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-60312C 81 9999906 02880311 3 I MIL-P-6031SC (PA) five minutes is allowed from the time wh

31、en the unit is re- moved from the polyethylene bag to the time when the cover is assembled to the test flaskti If this time period is ex- ceeded, discard the contents of the test flask, the test shall not be completed, and areplacement unit and a specimen shall be selected and preparqd, adhering to

32、all of the re- quirements for selecting the; original specimen. The toluene solution containing water from the specimen shall be refluxed by the application of heat to the test flask until the water level in the distillation trap maintains a constant level for 15 minutes minimum. The system shall th

33、en be allowed to cool to ambient temperature. Then, 40 to 50 milliliters of toluene, in 10 milliliter increments, shall be poured down the condenser to rinse any water droplets from the surface, The distilla- tion trap shall then be removed from the system, its contents stirred to assure complete se

34、paration of the toluene and water. The volume of the water shall be observed and recorded as V, estimated to the nearest 0.05 miililiter. The total percent of moisture content shall be calculated as follows: Percentage of moisture content = 100 V W Where : V = Volume of water, measured in milliliter

35、s. W = Weight of the specimen, measured in grams. 4.5.5 Static potential charge. - Place the specimen on an ungrounded surface, in an environment of not more than 55 percent relative humidity, and briskly rub with a rayon or silk cloth, not less than 25 strokes for a distanFe of 8 inches minimum, ea

36、ch stroke superimposed upon the preceeding stroke. The cloth used in this test shall be of a size and so arranged that there is no possibility of the operators hand touching the specimen during the test. men has been rubbed as required, the specimen shall not be touched in any manner. Measure the st

37、atic potentional by holding the detecting head of a Keithley Static Meter No. 600B, with detecting head No. 2503 (see 6.10) or sensor ele- ment of Enviro/Tech Sciences Inc., Model W100, Calibrated Electrostatic Charge Detector (or substantial equal) not more than 3/8 inch from the approximate center

38、 of the unit surface where the rubbing was accomplished. This determination shall be accomplished immediately after the last stroke of the rub- bing cloth. NOTE: Static potential charge measurements require stringent adherence to manufacturers recommended procedures, including calibration and head s

39、tandoff distances. Special attention should be given to preventing disturbance of the coaxial cable between the detector head and the electrometer during test when using the Keithley equipment. After the speci- 9 Provided by IHSNot for ResaleNo reproduction or networking permitted without license fr

40、om IHS-,-,-flIL-P-bO312C BI m 394Ob 0288035 5 M MIL-P-603122 (PA) 4.5.6 Resistance to surface blockina. - Resistance to surface blocking shall be determined as follows: The speci- mens shall be two halves comprising one set of mating molded components, or in the case of one part items, two similar c

41、omponents shall be the test specimens. The major surfaces sf the two components, or two halves, shall be placed ininti- mate contact so that the greatest possible surface contact is nade. Three such assemblies shall then be placed in an aiir circulating oven maintained at 150, plus or minus 2 degree

42、s F for a period of 30 minutes with each such assembly under an evenly distributed weight comprising 20, plus or minus one pound per square foot of contacted area. When the 30 minutes hav elapsed, the assemblies shall be removed from the oven and placed on a table or any flat surface sufficient in s

43、ize to accommodate the sample. The weights shall then be removed and the contacted surfaces in each assembly separated by lift- ing the uppermost part or half from the lowemst part or half of each two-piece assembly (6). Failure to immediately sepa- rat or any visual evidence of rupture or transfer

44、of surface coating in either part in any of the three assemblies shall he an indication of failure to comply with the requirement, 4.5.7 Inte rfty o structure. - This evaluation shall be performed as hlows: Over a clean smooth surface, the tcst unit shall be broken into approximately two equal parts

45、. Thoae two parts shall, in turn be broken in a similar manner. When possible, do not break across or through cavities. (The unit, prior to breaking, should be scored circumferentially close to the center of its length and width to the minimum depth necessary to be readily broken by hand pressure).

46、Shake out: any loose pellets onto the prepared surface. Then over the same surface using a stencil brush (with bristles measur- sing approximately (approx) 1-1/4 inch in length) hold the brush in an upright position and subject each fracture surface to reciprocating strokes of the brush until no fur

47、ther mater- ial is retained. Under no circumstances shall the brush bristles be suppressed more than 1/4 inch (approx). all xeleased material except discrete pellets. pellets. classed defective . Discard Any sample unit exceeding the requirement shall be Count retained (61 ndelt no ciJzcumokance4 4h

48、at.t the owezmoot pakt ah hd$ o$ each *wo piece aooembly be heed in paoikion to pheuen$ movement dulting thib phabe 06 the tebt. 10 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NIL-P-bO312C 81 777770b 0288036 7 MIL-P-60312C (PA) 4.5.8 Self-extingu

49、ishing property. - This determination shall be per3ormed prior to start of production on a contract and at the latest, When beads of a-different shipment than those previously used are introduced into the process. Twelve units of the product of the second container through the pre- expander shall be selected immediately after molding for test. One specimen measuring 2 x 6 inches (when possible) x 1/2 inch shall