1、MIL-I-3409 15 FEBRUARY 1951 SUPERSEDING Navy 17P8 (INT) (in part: 1 February 1945 Signal Corps Tentative 72-78 (in part) 1 February 1945 MILITARY SPECIFICATION PLASTIC-MATERIAL, MOLDING; RIGID THERMOPLASTIC, POLYDICHLOROSTYRENE; FOR USE IN ELECTRONIC, COMMUNICATIONS, AND ALLIED ELECTRICAL EQUIPMENT
2、This specification was approved by tha Departments 07 the Army, the Navy nzd the Air Force for we of procurement services of the respective Departments. 1. SCOPE I 1.1 Scope.-This specification covers the requirements for polydichlorostyrene mold- ing compounds for use in electronic, commu- nication
3、s, and allied electrical equipment. 1.2 Classification. - The polydichlorosty- rene molding compounds covered by this specification shall be of the following types, as specified (see 6.2) : Type EH-1 - High-frequency applica- Type EH-2 - Hight-f requency applica- tions, good heat resistance. tions,
4、high heat resistance. 2. APPLICABLE SPECIFICATIONS 2.1 Specifications.-The following specifi- cations, of the issue in effect on date of in- vitation for bids, form a part of this specifi- cation: FEDERAL SPECIFICATION LP-406 - Plastics, Organic: General Specifications, Test Methods. NAVY DEPARTMENT
5、 SPECIFICATION General Specifications for Inspection of Ma terial, 905083-51-(499) (Army.-Copies of specifications should be ob- tained from the procuring agency or as directed by that. agency. Both the title and identifying number or symbol should be stipulated when requesting copies.) (Navy.-Copie
6、s of Federal, Military, and Navy Department specifications may be obtained upon application to the Bureau of Suqplies and Accounts, Navy Department, Washington 25, D. C., except that activities of the Armed Forces should make application to the Commanding Officer, Naval Sup- ply Center, Norfolk 11,
7、Va. Both the title and iden- tifying number or symbol should be stipulated when requesting copies.) (Air Force.-Copies of Federal and Military speci- fications may be obtained upon application to the Commanding General, Air Matriel Command, Wright-Patterson Air Force Base, Dayton 1, Ohio. Both the t
8、itle and identifying number or symbol should be stipulated when requesting copies.) 3. REQUIREMENTS 3.1 Material.-The material shall consist of polydichlorostryene compression, injec- tion, or extrusion molding compounds so formulated as to meet the requirements of this specification. 3.1.1 Unifomit
9、y.-All molding compounds of the same brand from one manufacturer shall be uniform in textilre, in color (see 3.1.2), and in the specified properties as de- e- Copyright Communications - Electronics Command Provided by IHS under license with CRAINot for ResaleNo reproduction or networking permitted w
10、ithout license from IHS-,-,- MIL-P-3409 93 m 9999906 0334339 5 m MIL-P-3409 temined by the batch-acceptance tests. (See 4.2.3.) 3.1.2 Color.-The molding compounds shall be furnished in the colors, tints, or hues and with the tolerances specified or permitted. (See 6.2.) 3.1.3 Property values. - When
11、 specimens of the forms specified in table I are subjected to the required tests, the values obtained from any set of specimens for any specific property, after any one conditioning pro- cedure specified in table I, shall be averaged; and the average value so obtained shall be not less than the mini
12、mum nor more than the maximum (as applicable) specified in table I. 4. SAMPLING, INSPECTION, AND TEST PROCEDURES 4.1 Classification of tests.-The methods of sampling, inspection, and tests shall be classified as follows : Inspection tests. a. Pilot-batch-approval b. Batch-acceptance 4.2 Inspection t
13、ests. - Inspection tests shall be performed at the point of manufac- ture under the supervision of the Govern- ment inspector. They shall consist of pilot- batch-approval tests and batch-acceptance tests as indicated in table I. 4.2.1 Inspection procedures for Navy pur- chases. - For Navy purchases,
14、 the gen- eral inspection procedures shall be in accord- ance with the General Specification for In- spection of Material. 4.2.2 Pilot-batch-approval. - The pilot batch shall consist of the first batch of a specific type and brand of molding compound produced for Government end use under this. speci
15、fication, and shall not be required to be repeated unless a significant change occurs in the molding compound. (See 4.2.3.) A batch is defined as a unit of the molding com- pound produced by one continuous production run or by a blend of two or more continuous production runs. Approval of the pilot
16、batch shall be obtained before proceeding with the production of further batches under t.his specification. 4.2.3 Batch-acceptance.-Batch-acceptance tests shall be made on each batch of molding compound after pilot-batch approval has been obtained and shall be the basis 01: which acceptance or rejec
17、tion of the batch is made. If significant differences between the results of batch-acceptance and pilot-batch-approval tests indicate that a change has occurred in the composition of the molding compound or in its processing, the inspector may at his discretion require the repetition of any or all o
18、f the pilot-batch-approval tests, to insure conformance of the molding compound to this specification. 4.2.4 Test equipment arid impecton facii- ties.-The manufacturer shall furnish and maintain all necessary facilities and ment for making all tests. The test eqzip- ment shall be adequate in quantit
19、y to entibie inspection to keep up with productim zw? shall be of sufficient accuracy and qualit:- to permit the performance of the reqrike9 tests. 4.2.5 Results of tests.-A copy of the re- sults of the pilot-batch-approvaL and batch- acceptance tests shall be fiirnished the Gor- ernment inspector.
20、4.2.6 Re jeetion.-Failure to comply with any of the requirements of table I shall re- sult in rejection of the batch of molding compound. 4.3 Test procedures. 4.3.1 Specmens. 4.3.1.1 Number. - The number of speci- mens to be tested shall be as specified in table I. 2 Copyright Communications - Elect
21、ronics Command Provided by IHS under license with CRAINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-flIL-P-3LlO7 73 =. 9979906 0334320 I a MIL-P-3409 nl I I SI I I h J minmu: I I I $ f i ! r - i 6 Copyright Communications - Electronics Command Provided by IHS und
22、er license with CRAINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-3407 93 - 7777706 OLLLi3ZL 3 W MIL-P-3409 4.3.1.2 Form.-The form of the standard test specimens shall be as described in the applicable method of Specification L-P-406, and as modified in tab
23、le I herein. 4.3.1.3 Preparation. 4.3.1.3.1 From compression- or injection- molding compounds.-These specimens shall be molded by methods representative of sound practice. 4.3.1.3.2 From extrusion compounds.-The x- by $-inch bars shall be die-cut or ma- chined from extruded strip. Ail other speci- m
24、ens shall be die-cut or machined from extruded strip, or from compression- or in- jection-molded blanks. 4.3.1.4 Tolerances. - Unless otherwise specified, tolerances on dimensions shall be a5 percent. 4.3.1.5 Conditioning.-Specimens shall be conditioned before test, as specified in table I. 4.3.1.5.
25、1 Nomenclature.-The following let- ters shall be used to indicate the respective general conditioning procedures : Condition A -As received; no special Condition C -Humidity conditioning. Condition D -Immersion conditioning in distilled water. Condition E -Temperature condition- ing. Condition des.-
26、Desiccation condition- ing, cooling over silica gel or calcium chloride in a desiccator at 23“ C. for 16 to 20 hours. conditioning. 4.3.1.5.2 Designation. - Conditioning pro- cedures shall be designated as follows: a. A capital letter indicating the gen- eral condition of the specimen; ie., as recei
27、ved, humidity, immersion, or temperature conditioning. b. A number indicating in hours the duration of the conditioning. c. A number indicating in degrees centi- grade the conditioning temperature. d. A number indicating relative humid- ity, whenever relative humidity is controlled. The numbers shal
28、l be separated from each other by slant marks, and from the capital letter by a dash. A sequence of conditions shall be denoted by use of a plus (+) sign between the successive conditions. 4.3.1.5.3 Conditioning procedures.-Condi- tioning procedures shall be as specified in table II. 4.3.1.6 Measure
29、ment of specimens.-Speci- mens shall be examined, and dimensions re- quired to be recorded shalI be measured to the nearest 0.001 inch by using a suitable micrometer or vernier caliper. All other di- mensions shall be measured to the nearest %2 inch. Such measurements shall be made before conditioni
30、ng in each case and after completion of the test whenever required. 4.3.2 Methods of test.-The test methods shall be in conformance with the applicable method in Specification L-P-406 (see table I) and as modified below: 4.3.2.1 Water abso?+ption.-The method shall be as specified in method 7031 of S
31、peci- fication L-P-406 ; except that oven condition- ing at 50“ C. shall be for 48 hours, and im- mersion shall be in water at 23“ 12“ C. 4.3.2.2 Insulation resistance. - The appa- ratus specified in method 4041 of Specifica- tion L-L-406, or equivalent shall be used. Electrodes shall be Pratt and W
32、hitney No. 3 tapered pins or equivalent. The test potential shall be applied between the pair of electrodes when inserted successively in the numbered holes (see fig. i), and the aver- age of the three readings shall be taken as the reading for the specimen. Copyright Communications - Electronics Co
33、mmand Provided by IHS under license with CRAINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-3407 73 m 7777706 0114322 5 TABLE II.-Conditioning procedures Designation C-96/23/60 + D-48/50 + D-% /23 _- E-48/60 + des. (for water + D-24/23 - absorption) E-12/60
34、to E-18/60 (for deformation under load) Time tolerance Oven or air -O, + indef. -O, + 2 hrs. 4, + 2 hrs. -0, + 2 hrs. - Cool water - -O, + 2 hrs. - -O, + 2 hrs, - Test tempera- ture and humidity 23“ f 6“ C., 50% f 5% RH 23“ Copyright Communications - Electronics Command Provided by IHS under license
35、 with CRAINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-3407 73 m 777770b OLL4324 7 m Ir be made under oil at a frequency not exceed- ing 100 cycles per second. Electrodes shall be Pratt and Whitney No. 3 tapered pins, or equivalent. The test potential shal
36、l be ap- plied between the pair of electrodes when inserted successively in the numbered holes (see fig. i), and the average of the three readings shall be taken as the reading for the specimen 4.3.2.5.1 Short-time test. - The voltage shall be increased uniformly at the rate of 500 volts per second.
37、 4.3.2.3.2 Step-by-step test. - The voltage shall be increased in the increments shown in table III. It shall be held at each step for 1 minute and then changed to the next higher one within 10 seconds. This process shall be continued up to failure. 4.3.2.6 Impact strength.-The test shall be rnade a
38、s specified in method 1071 of Specifi- cation GP-406, except that the test specimen shall be as shown on figure 2 herein. 4.32.7 Dforwzation under load. - The method shall be as specified in method 1101 of Specification L-P-406, except that precon- ditioning and conditioning shall be from 12 to 18 h
39、ours at 50“ C. and the total load ap- plied shall be 70 pounds. MIGP-3409 4.4 Test reports. - Test reports shall be made as specified in section I, paragraph in addition, a summ mary sheet of test results shall be furnished, 4.4.1 Accuracy of caZcuZtbns.-Observed or calculated values shall be rounde
40、d off to the nearest digit in the last right-hand place of figures used in expressing the specified value, except as follows: a. From 500 to 1,000 -to the nearest 5. b. From 1,001 to 10,000-to the nearest 100. 5. PREPARATION FOR DELIVERY 5.1 Not applicable to this specification. 6. NOTES 6.1 Intende
41、d use.-Parts made from these types of molding compounds are intended for high-frequency applications. They. retain their properties relatively unimpaired over a wide range of frequencies, tempeatures, and humidities. They possess excellent di- mensional stability and stability at low tem- peratures.
42、 Heat resistance is relatively high for thermoplastic materials. ALL DIMENSIONS IN INCHES. FIGURE 2.-Zmpact strength. test specimen. (See 4.8.2.6.) 7 Copyright Communications - Electronics Command Provided by IHS under license with CRAINot for ResaleNo reproduction or networking permitted without li
43、cense from IHS-,-,- MIL-P-3L107 73 W 777770b 0334325 O W . : -. . . . MIGP-3409 6.2 Ordering data. - Procurement docu- a. Title, i;ti:iber, and date of this speci- ficatior;. ments should specify the following: . b. Type and the fact tiia: tL.e Govern- ment may have formulated, furnished, (J:* i:! a
44、ny way supplied the said drawings, specificaticne, or other data is not to be regarded by implication or cthermise as in any manner licensing the holdes GI- any other person or corporation, or conveying any sights of permission to manufacture, use, or sei1 any paten& invention that may in any Kay be related thersle Custodian: Other interest: Army-Signal Corps Arm y-EOQT Navy-AOShS Air Force. Copyright Communications - Electronics Command Provided by IHS under license with CRAINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
