1、r=- MIL-C-L25L 13 7777906 0427007 b W ? 6- PI MIL-C- 81251(WP) 20 April 1965 -. . MILITARY SPECIFICATION CLOTH, SILICA, PHENOLIC IMPREGNATED This specification has been approved by the Bureau of Naval Weapons, Department of the Navy. I. SCOPE 1.1 Scope. This specification covers the requirements for
2、 one type of silica cloth, impregnated with a phenolic in the sehi-cured state. 2. APPLICABLE DOCUMENTS 2.1 The following documents, of the issue in effect on date of invi- tation for bids or request for proposal, form a part of this specification to the extent specified herein. SPECIFICATIONS Milit
3、ary MIL-P-116 MIL-R-9299 Department of the Navy Bureau pif Naval Weapons os 9349 STANDARDS Federal Federal Test Method Standard 406 Preservation, Methods of Resin, Phenolic, Low Pressure Laminating Fabric, Woven, Vitreous Fiber, For Plastic Laminates Plastics, Methods of Testing MIL-STD- 105 MIL-STD
4、- 129 Sampling Procedures and Tables For Inspection by Attributes Marking for Ship.ment and Storage FSC ,8305 Licensed by Information Handling ServicesMIL-C-1251 13 = 9997906 0427OO (When requesting any of the above documents, give the title and complete designation of the item shown above. Copies o
5、f this specification and other unclassified specifications, standards and publications required by con- tractors in connection with specific procurement functions may be ob- tained from the Commanding Officer, Navy Supply Depot (CDS), 5801 Tabor Avenue, Philadelphia, Pennsylvania, 19120.) 3. REQUIRE
6、MENTS 3.1 Preproduction samples. Unless otherwise specified in the contract or order, preproduction samples of the impregnated cloth shall be manu- factured using the methods and procedures proposed for the production. The sample shaU be tested as specified in Section 4 herein and is for the purpose
7、 of determining that, prior to starting production, the contractors production methods are capable of yielding items that comply with the technical requirements of the contract. After satisfactorily passing ail the preproduction tests specified herein, no changes in raw materials and processing of m
8、aterials fur production shall be made without prior written approval of the procuring activity. 4- 3.2 Data requirements. No data is required by this specification or by applicable documents referenced in Section 2 unless specified in the contract or order (see 6.2). 3.3 Material. The raw materials
9、used to make the finished product shall be silica cloth, conforming to Os 9349, Qpe II, except that it shall contain a minimum of 96 percent silica, and a phenolic resin conforming to MIL-R-9299, Qw II, Class 2. 3.4 Physical and chemical properties 3.4.1 Resin solids content. The uncured resin-impre
10、gnated cloth shali contain 28 f 3 percent by weight of resin solids. contain 4 to 7 percent by weight of volatile matter. 3.4.2 Volatiles content. The uncured resin-impregnated cloth shaU 3.4.3 Resin flow. The uncured resin-impregnated cloth shali have a 2 Licensed by Information Handling ServicesL
11、MIL-C-B125L 13 W 777770b 0427007 T d MIL-C- 81251(WP) resin flow of 15 to 21 percent. -3.4.4 Flexural strength. The flexural strength of the cured resin- impregnated fabric shall be a minimum average of 19,000 pounds per square inch (psi) at 75 f 5 degrees Fahrenheit (F). No individual value shaU be
12、 below 18,000 psi. 3.4.5 ltimate tensile strength. The ultimate tensile strength of the cured resin-impregnated fabric shall be a minimum average of 12,000 psi at 75 f 5 degrees F. NO indiviaal value shall be below 11,000 psi. 3.4.6 Specific gravity. The specific gravity of the cured res&-impregnate
13、d fabric shall be a minimum of 1.67. . 3.5 Workmanship. The material shaU be uniform in qpality and shall be free from impurities and other defects that could adversely affect its use. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for inspection. Unless otherwise specified in the contract or pu
14、rchase order, the supplier is responsible for the performance of all inspection requirements as specified herein. Except as otherwise specified, the supplier may utilize his own facilities or any commercial laboratory acceptable to the Government. The Government reserves the right to perform any of
15、the inspections set forth in the specification where such inspections are deemed necessary to assure supplies and services conform to prescribed requirements. 4.2 Classificatiai of inspections. inspection of the insulation shall be classified as follows: I a. Preproduction inspectiai (see 4.4) b. Qu
16、ality conformance inspection (see 4.5) 4.3 Sampling 4.3.1 Preproduction sample. A preproduction sample of 3 specimens manufactured in accordance with 3.1 shall be subjected to the.preproduction tests detailed in 4.4 at an activity designated by the procuring activity. 3 Licensed by Information Handl
17、ing ServicesFurther proctuction of the phenolic -impregnated cloth by the supplier prior to the approval of the preproctuctbn sample, shall be at the suppliers risk. 4.3.2 Quality conform-ance inspection sampling, Except as otherwise specified, the sampling plans and procedures set forth in MIL-STD-
18、105, level II shall be used in the determination of acceptability of the phenolic- impregnated cloth as specified in 4.5. Samples shall be selected from material prior to any slitting. 4.3.3 Inspection lot. An inspection lot of impregnated cloth shall consist of all material presented for acceptance
19、 at one time and produced in a single manufacturing run under homogeneous conditions of manufacture. 4.4 Preproduction inspection. The preproduction sample, after satisfactorily passing the quality conformance inspections detailed in 4.5, shall be subjected tothe following tests and examinations. m
20、4.4.1 Mechanical test specimen preparation. From the broad-goods samples provided, prepare a parallel laminate 10 X 12 inches in size with a cured thickness of 0.125 + 0.010 - 0.020 inch, The warp direction of the fabric shall be in the 10-inch direction. Cure the laminate as follows: I Place the la
21、minate in a preheated press at 325 f 10 degrees F, close rapidly, then apply pressure of 100 f 10 psi and cure 1 hour. 2. Post cure in a circulating-air oven at 325 f 5 degrees F for 3 to 3- 1/4 hours. A minimum of 5 specimens, 0.125 + 0,010 - 0.020 inch thick, shall be run for each property. 4.4.11
22、 Flexural strength test. The flexural strength shall be deter- mined in accordance with Federal Test Methods Standard 406, method 1031. 4.4.1.2 Ultimate tensile strength test. The ultimate tensile strength 4 Licensed by Information Handling Servicesk - MIL-C-81251 13 = 7799706 0427011 8 MIL-C- 81251
23、 (WP) i shall be determined in accordance with Federal Test Methods Standard 406, method 1011. 4.4.1.3 Specific gravity test. The specific gravity shall be determined in accordance with Federal Test Methods Standard 406, method 5011. 4.5 Quality conformance inspection 4.5.1 Visual examination. Visua
24、lly examine all containers in a lot to determine compliance with 3.5 and Section 5. 4.5.2 Volatiles content test. Cut five 4 inch.X 4 inch square specimens on he bias from random locations on.e-ach sample of broa-goods. Weigh each specimen to the nearest milligram (0.001 gram) and then suspend each
25、in a circulating-air oven maintained at 325 f 5 degrees F for 10 f 0.5. minutes. On removing the specimens from the oven, cool to room tem- . perature and reweigh each specimen to the nearest milligram. Calculate the volatile content as follows: . . where: Wo = Original weight, grams W1 = Weight of
26、specimen after volatiles removed, grams The average and range of the five values shall be reported. 4.5.3 Resin solids test. T.he five specimens used for the volatile content tests shall be placed in previously heated muffle furnace. The samples shall then be maintained at 1600 f 50 degrees Ffor a m
27、inimum of one hour or until a white fabric free of carbon remGns. Cool the spe- cimens to room temperature and reweigh each specimen to the nearest milligram. Calculate the resin solids content as follows: . 5 .- . -i 5 Licensed by Information Handling Servicesd MIL-C- 8125i(WP) Resin solids content
28、, weight percent = w1-w2 x100 w1 where: W1 = Weight of specimen after volatiles are removed, grams W2 = Final weight of specimen after ignition at 1600 degrees F, grams The average and range of the five values shall be reported. 4.5.4 Resin flow test. Cut twenty-one 4 inch X 4 inch squares on the bi
29、as from random locations on each sample. Stack seven of these squares to form a specimen and place a sheet of O.O5-inch thick parting material on each side of the specimen. Place the specimen in the center of a pre- heated press with platen maintainedat 325 I 10 degrees F. Immediately close the pres
30、s and apply a dead-weight load on the sample of 1001 5 psi. Cure the specimen for 10 minutes minimum, remove from the press and while still hot remove the parting agent from the specimen. Allow to cool to room temperature and weigh to the nearest milligram. Care should be exercised in handling the s
31、pecimen after removing it from the press so as not to lose any of the flash. After determining the specimen weight with the resin flash, remove this flash and reweigh the specimen to the nearest milligram. Calculate the resin flow as follows: Resin flow, weight percent = w3-w4 x100 w3 where: W3 = We
32、ight of specimen after cure with flash, grams W4 = Weight of specimen after cure with flash removed, grams The average and range of the three results shall be reported. 4.6 Acceptance criteria 4.6.1 Preproduction. Failure of any sample to comply with any re- quirement of this specification shall be
33、cause for rejection of the sample. 6 -. _. Licensed by Information Handling ServicesMIL-C-8125L 13 W 9_777706 OLI27033 I W MIL-C- 81251(WP) a 4.6.2 Quality conformance. Failure of any sample to comply with any requirement of this specification skiall be cause for rejection of the sample. Acceptance
34、of the lot shall be based upon an Acceptable Quality Level (AQL) of 1.0 percent as per MIL-STD-105, level II, nord inspection, single sampling. One hundred percent inspection shall be required when quantity of material on order is &low MIL-STD-105, level II. 5. PREPARATION FOR DELIVERY 5.1 Preservat
35、ion, packaging and packing. Unless otherwise specified by the procuring activity, the preservation, packaging and packing shall be in accordance with MIL-P-116, method .III. 5.2 Marking. Each container shall be marked in accordance with MIL-STD-129. Marking shall include, but not be limited to, the
36、following infor mation: a. Manufacturers name and location b. Material trade name c. Net weight or volume e. Shelf life or storage limitations f. Number and revision letter of this specification . d. Lot number, batch number and date of manufacture 6. NOTES 6.1 intended use. The material purchased i
37、n accordance with this specification is intended to be used in rocket motors. 6.2 Ordering data. Procurement documents should specify, but not be limited to, the following information: a. Title, number and revision letter of this specification b. Minimum lot size, if applicable c. Whether preproduction sample is required d. Place of delivery e. Size bf container f. Request for test data g. Request for broad-goods samples Licensed by Information Handling Services
