1、MILITARY SPECIFICATION MIL-P=145?1A 7 JANUARY 1960 SUPERSEDING MIIA-14571 (Ora) 30 JUNE 1957 PLASTIC, POLYSTYRENE, MODIFIED; FABRICATED PARTS This specificatkn has been approved by the Department of Defense and ts man- datwg for use by the Depmtments of the Army, the Navy, and the Air Fome. 1. SCOPE
2、 PPP-B-636 - Boxes, Fiber. 1.1 This specification covers requirements for parts fabricated from qualified modified polystyrene plastic conforming to Specifica- tion LM-525. 2. APPLICABLE DOCUMENTS 2.1 The following documents. of the issue in effect on date of invitation for bids, form a part of this
3、 specification. SPECIFICATIONS FEDERAL L-M-525 - Molding Plastic, Poly- styrene, Modified. E-P-406 - P 1 a s ti c s, Organic: General Specifica- tions, Test Methods. PPP-B-585 - Boxes, Wo o d , Wire bound. PPP-B-591 - B o x es , Fiberboard, Wood-Cleated. PPP-B-641 - Boxes, Wood, Cleated- Plywood. PP
4、P-B-621 - Boxes, Wood, Nailed and Lock-Corner. MILITARY MIL-P-116 - Preservation, M et h- ods of. MIL-B-117 - Bags, Interior, Pack- aging. MIL-B-138 - Boxes, Wood, Fiber- board Lined for Overseas Shipment, MIL-B-10377 -Box, Wood, Cleated, Veneer, Paper-Ov- erlaid. STANDARDS FEDERAL FED, TEST METHOD
5、STD. WO. 141 - Paint, Varnish Lacquer and Related Materials ; Methods of Inspection, Sampling, and Testing. Rubber ; Sampling and Testing (Test Method). FED. TEST METHOD STD. NO. 601 - MILITARY MIL-STD-105 - Sampling Procedures and Tables for In- spection by Attri- butes. Provided by IHSNot for Resa
6、leNo reproduction or networking permitted without license from IHS-,-,-MIMTD-129 - Marking for Shipment and Storage. (Copies of specifications, standards, drawings, and piiblictions required by contractors in connection with specific procurement functioiis should be ob- tained froin tile procuiSiig
7、agency or as directed by the contracting officer.) 3. REQUIREMENTS 3.1 Materid, The par shall be fabricated froin material which has been qualified in accordance with Specification L-M-525. The fabricator shall state which qualified mate- rial (type number, manufacturers number, and color number) wa
8、s used to fabricate each lot of parts. 3.2 Dimensions. The dimensions anil toler- ances of the fabricated parts shall be in ac- cordance with the i*equirements of the ap- plicable drawings or specifications and con- tract or purchase order. 3.3 Identity values (for Army Ordnance Corps procurement on
9、ly). For Army Ord- nance Corps gvociii*ement, the value obtained and recorded at the time of qualification of the material foi* specific gravity, plus the values obtained for the following additional properties shdl be used for reference in identifying initial production lot and pro- clrrction lot f
10、abricated parts : (a) Iodine number, when detei*mined as specified in 4.6.2.2. (b) Diirometer bni*diiess, when deter- mined as specified in 4.62.3. 3.3.1.1 Specific g?*avity. The specific grav- ity shall fall within the limits specified in table I of Specification L-M-525. In addi- tion, for Army Or
11、dnance Corps procure- ment, specific gravity shall lie within plus or minus (Lb717 7 -I MILP-I4571 A ance with Standard MIL-STD-105. 4.6.1 Visual. Sample units shall be exam- I ined for defects, and at the acceptable qual- ity levels shown in table II. 4.4.2 Samplhg for .identity tests, The por- tio
12、n of material submitted in accordance with section 6 of Specification L1M-526 shall liave been used for obtaining the material identity values. 4.4.3 Sampling fop tests. A minimum of seven parts or 4 ounces by weight, which- ever is greater, Bhall be taken at random for testing. For Army Ordnance Co
13、rps testing, zipecific gravity, durometer hardness1 and 4.5.3 Pres emation, pwkaging, packing, iodine number may be run on the same parts, and marking f-0 shipment, Examination shall be for the defects and at the acceptable quality levels shown in table II. 4.5.2 iil, 4.L2.1 Gages. All necessary gag
14、es and other measuring tools shall be furnished by the contractor and approved by the Govern- ment. Metho of inspection Visual Visual or X-ray as L-STD-105 shall be used as a hl. for a minimum of 4 hours and tested at 23O f 1OC. (73.4 -c- 1.8F.) and 50 I: 2 percent relative humidity. - 1Unless othon
15、vlsa specified by the procuring agency, Standard 1 L% 1.5.2.1. 4.6 Testing. 4,6. Test specintens. Unless otherwise specified, all specimens shall be conditioned a f exurnination 1 Defect Color improper , . . . . . . . Holes, air and gas pockets, or other porosity imper- fections. Cracks, splits, etc
16、., from machining operation. Cracks, chipped edges, etc., and other surface imper- Marking on parts mislead- Inserts, holes, Iugs, etc., Threads not smooth, clean, Parts not individually Box liner material impro- Liner torn or pierced . . , . Liner no sealed . . . . . . . . . Gross weight, maximum .
17、 . Boxes improperly closed . Marking misleading or un- identifiable, Contents loose , , . . , . . , . . fections. ing or unidentifiable, improper, etc. wrapped. per. available. Visual Visual Visual Visual Visual Visual Visual Visual Visual Approved scale 2 Visual Visual Manual Provided by IHSNot for
18、 ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-14571A 4.6.1.1 Specific grmitu. Three specimens shall be prepared for testing in accordance with method 5011 of Specification L-P-406 and 4.6.1. Specimens tested ,at the time of 4.6.2.1 Specific gravity. Specimens pre-
19、 qualification of the material (see Specifica- pared in accordance with 4.6.1.1 shall be tion L-M-525), shall be portions of broken tested in accordance with method 5011 of tensile specimens. Specimens from lots of Specification L-P-406. of the tests shall be the average of the values obtained for t
20、he test specimens, I I . Parts which are too large 4.6.2.2 iodine number. Specimens prepared for the specified test method may be cut 01 in accordance with 4.6.1.2 shall be tested in broken into smaller pieces, If the part con- accordance with method 5061 of Federal tains an insert, it shall be remo
21、ved before Test Method Standard No. 141 except that making the determination OF a correction 0.20 f 0.02 grams of the composite shall be made for its volume and weight. weighed as the sample for testing. I I more man one unir;. Lpproximately tall be taken :amicated parts and .t the time of see Speci
22、fica- mber shall be from two ten- xt specimen. Irillings shall 01 tne part in the e number de- plicate on the 1 not vary by . -2:- 4.6.2.3 Durometer hardness. Specimens prepared in accordance with 4.6.1.3 shall be tested with a type D Shore durometer or equivalent. The instrument shall be construc-
23、ted in accordance with instructions supplied by the manufacturer of the equipment. Cali- bration of the durometer, if required, shall be in accordance with the method recom- mended by the manufacturer of the durom- eter (see 6.3). If a durometer stand is avail- able, the specimen shall be placed on
24、the stand beneath the durometer so that the surface being tested is parallel to the base. The durometer is to be lowered by means of A C: l Q no,wfimnfnfi* hnnvlmnoo Three speci- :k, built up, if two or more :ordance with .ently large to LLullL uIuuLcllrG “2 0.25 inch in B,. th, ;nd,n+qtiOn point to
25、 a knob so that the indentor is applied per- pendicular to the surface. Firm pressure shall be applied as rapidly as possible, but without shock, so that the pressure plate makes firm contact with the surface of the specimen. The durometer indentation read- ing shall be taken as soon as the indicati
26、ng hand of the dial comes to rest or, if this is not possible, at the moment a definite change in the needle speed is noted. When a durom- eter stand is not available, the durometer shall be grasped between the thumb and third and fourth fingers, resting the index finger on the top of the instrument
27、. The durometer shall be placed on the test speci- men keeping the base of the instrument par- allel to the surface of the specimen, This method of application allows seating the plate around the indenter point, flush with the test surface, with a minimum of rockinn. I 4.6.1.4 Stress release tempera
28、ture. . 4.6.1.4.1 Initiaial production lot. Thrce parts shall be prepared in accordance with 4.6.1. One or more additional parts shall be select- ed for making preliminary tests. 4.6.1.4.2 Production Eot. Three parts shall I be prepared in accordance with 4.6.1. I 4.6.2 Test methods. The reported re
29、sults Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-14671A * Only suficient pressure to ensure contact of the pressure plate with the specimen shall be applied, The durometer indentation read- ing shall be taken as soon as the indicating hand
30、 of the dial comes to rest or, if this is not possible, at the time a definite change in needle speed is noted, 4.6.2.4.1 Initial pmdmtzon bt. Measure- ments of the parts prepared in accordance with 4.6.1 shall be taken across three ap- proximately mutually perpendicular axes and made at 28 2 I0G. (
31、73.4 to 1.8F.). For example, if the part is a cylinder, meas- urements shall be taken of the length and of two diameters, If the part is irregular in shape, the locations at which the measure- ments are made shall be chosen to be as nearly representative of the molding as is reasonably possible. Fla
32、t parts shall be meas- ured over two mutually perpendicular axes in the plane of the surface, Thin-walled hol- low cylinders shall be tested by measuring the changes in length and circumference after cutting to shorter lengths if necessary. This test is not applicable to thin-walled hollow parts hav
33、ing compound curvature. The measurements shall be made with an accuracy of rt= 0.OO. inch or I: 0.4 percent, whichever ia greater, The part shall then he placed in a constant-temperature oven and shall be kept there for a period of time which depends upon the maximum thickness of the part. The heati
34、ng period correspond- ing to the various thicknesses shall be as shown in table II, If the molding is too large foi. any available oven, a portion of the mold- ing shall be cut OR and shall be used as the specimen. The specimen, when in the oven, shall rest on a material of low thermal con- ductivit
35、y so that most; of the heating of the specimen will be by contact with the hot air. In addition, the specimen shall be placed in such a position that distortion due to the weight of the specimen will tend to be re- duced to a minimum. At the end of the time indicated in table II, the specimen shall
36、be removed from the oven and shall be allowed , to cool to 23 2 1OC. (73.4 -i- 1.8F.). This procedure shall be repeated at succes- sively higher temperatures, using tempera- ture intervals of 543. (9F.) until the stress- release temperature at which any one of the measured dimensions of any one of t
37、he parts shows a change from the original value of 3 percent or more. The original oven tem- perature shall be not less than 5OC. nor more than 2OOC. below the stress-release temperature of the part being tested. Pre- liminary tests, using larger temperature in- tervals, shall be used to determine t
38、he start- ing temperature. The temperatures shall be even multiples of 5C. The locations of the measurements shall be noted on the record. TABLE II. Heating period for thickness of part to be. tested Thickness of part, inches. maximum 0.255 or less 0.256 to 0.375 0.376 to 0.505 0.506 to 1.005 1.006
39、or more Heating period houra 5 “i 1 2 a 4.6.2.4.2 ProZductwn lot. Farts prepared in accordance with 4.6.1 shall be measured in the same manner as specified in 4.6.2.4.1. These parts shall be placed in an oven set at a temperature 15OC. below the stress- release temperature determined on the intial p
40、roduction lot, and shall be heated in the same position and for the same length of time as was done when testing the initial production lot, except that only one heating period shall be used. The parts shall be cooled .and remeasured. If no measurement on any of the three specimens has change: 3 per
41、cent or more from its original value, the lot shall be considered as having con- formed to the requirements specified in 3.3.2.4 4.7 Rejection. 4.7.1 Examination, Any nonconforming 6 I Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-VIL-P-Lq57LA 73 =
42、 7777Oh OLLb722 9 = J- I MLP-14571A i part when inspected in accordance with 4.5, shall be rejected and if the number of non- conforming parts exceeds the acceptance number as specified, the entire lot shall be rejected. 4.8.1 Rejected lots may be resubmitted in accordance with Standard l%IL-STD-105
43、. 5. PREPARATION FOR DELIVERY 5.1 Preservation and packaging. 4.7.2 Testing. A lot shall be rejected for failure to comply with any of the test re- 5.1.1 Level A. Unless otherwise specified, quirements when tested in accordance with cleaning, drying, presekvative application, 4.6. and unit packaging
44、 of plastic fabricated parts shall be governed by the applicable specifications shown in table III, as specified. 4.8 Reinspection. TABLE III. Specification governing level A ?n.esemmtzo?z and packaging of fabricated plastic payts Task Cleaning of metal inserts . . . . Drying of metal inserts . , Pr
45、esemative application to nietal inserts Unit packaging 1 . , . . . . . . . . . . Governing specification Parts with metal inserta MIL-P-116 method C-l. method D-l. Any applicable MIGP-116 MIL-P-116. method, method IA8 or MIL-BL117 class e2. MIGP-116 Parts without metal inserts . . . MIGP-116 method
46、IC-3 * Packaged in quantities specified in the contract or purchase order. 2 Applicable type of interior packaging bags. ,5.1.2 Level C. Cleaning, drying, preserva- tive application, and unit packaging shall be in accordance with manufacturers best com- mercial practice. 5.2 Packing. 5.2.1 Level A.
47、Unless otherwise specified, plastic fabricated parts shall be packed in ovesseas type or class shipping containers conforming to Specification PPP-B-585, PPP-B-591, PPP-B-601, PPP-B-621, PPP- B-636, MIL-B-138, 01 MIL-B-10377. AS far as practical, containers shall be of uni- form shape and size, be o
48、f minimum cube and tare consistant with the protection re- quired, and contain identical quantities. Con- tainers shall not exceed 200 pounds gross weight and shall be closed and strapped in accordance with the applicable container specification or appendix thereto. 5.2.2 Level B. Unless otherwise s
49、pecified plastic fabricated parts shall be packed in domestic type or class shipping containers conforming to the requirements of Specifica- tion PPP-B-585, PPP-B-591, PPP-B-601, PPP-B-621, PPF-B-636, or MIL-B-10377. As far as practical, containers shall be of uniform shape and size, be of minimum cube and tare consistent with the psotection re- quired, and contain identical quantities. Con- tainers shall not exceed 200 pounds gross weight and shall be close
