1、MIL-S-81256 13 7997706 0427015 5 = MIL-S-m+ W?) 4 March 1965 .-2. - : . l. + .-y: MILITARY SPECIFICATION SILICA FABRIC, PHENOLIC IMPREGNATED This specification has been approved by the Bureau of Naval Weapons, Department of the Navy 1. SCOPE 1.1 Scope. This specification covers one type of choppedsi
2、lica fabric impregnated with a phenolic resin containing silica reinforcement, and supplied in approximate 1/2 -inch squares. 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
3、 extent specified herein. SPECIFICATIONS Military MIL - P- 1 16 MIL-R-9299 Preservation, Methods of Resin, Phenolic, Low - Pressure Laminating STANDARDS Military MIL-STD- 129 Marking for Shipment and Storage Department of the Navy Bureau of Naval Weapons os 9349 Fabric, Woven, Vitreous Fiber, For Pl
4、astic Laminates (When requesting any of the above documents, give the title and complete designation of the item shown above. Copies of this specification and other unclassified specifications, standards, and publications required by con- tractors in connection with specific procurement functions ma
5、y be obtained from the Commanding Officer, Navy Supply Depot (CDS), 5801 Tabor Avenue, Philadelphia , Pennsylvania , 19 1 2 O. ) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I 2.2 Other publications. The following documents form a part of this spe
6、cification to the extent specified herein. Unless otherwise indicated, the issue in effect on date of invitation for bids or request for proposal,. shall apply, Q. PUBLICATIONS American Society for Testing and Materials ASTM D 792-60 ASTM D 695-54 ASTM D 651-48 Method of Test for Specific Gravity an
7、d Density of Plastics Method of Test for Compressive Properties of Rigid Plastics Method of Test for Tensile Strength of Molded Electrical Insulating Materials (Application for copies should be addressed to the American Society for Testing and Materials, 1916 Race Street, Philadelphia, Pennsylvania,
8、 19103,) 3. REQUIREMENTS 3.1 Preproduction sample. Unless otherwise specified in the contract or order, preproduction samples of the fabric shall be manufactured using the methods and procedures proposed for the production. The sample will be tested as specified in Section 4 herein and is for the pu
9、rpose of deter- mining that, prior to starting production, the contractors production methods are capable of yielding items that comply with the technical re- quirements of the contract, After satisfactorily passing all the preproduction tests specified herein, no changes in raw materials and proces
10、sing of materials for production shall be made without prior written approval of the procuring activityo 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). 2 Provided by IHSNot for R
11、esaleNo reproduction or networking permitted without license from IHS-,-,-c MIL-S-125b 13 9999906 0427037 7 MIL -s -81255 (id?) 3.3 Material. The material shall be composed of a resin meeting Specification MIL-R-9299, Type II, Class 2, a resin reinforcement (minimum 98-percent pure silica) a silica
12、fabric meeting OS 9349, - Type III. The reinforcement shall be no less than 5 nor more than 10 percent of the total weight of the. impregnated fabric. 3.4 Physical and chemical properties 3,4.1 Uncured impregnated fabric 3.4.1.1 Resin solids content. The resin solids content of the uncured material
13、shall be 25 f 2 percent. 3.4,1.2 Volatile content. The volatile content of the uncured material shall be 3.75 f 1.25 percent, 3.4,1.3 Flow. The flow percent shall be 9.5 f 5.5 percent. 3.4.2 Cured impregnated fabric 3.4-2.1 Specific gravity. The minimum specific gravity of the cured material shall b
14、e 1.77. 3.4.2.2 Compressive strength. The minimum compressive strength of the cured material shall be 26,000 pounds per square inch (psi). 3.4.2.3 Tensile strength, The minimum tensile strength of the cured material shall be 8,500 psi. 3.5 Workmanship. The material shall be uniform in quality and sh
15、all 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 purchase order, the supplier is responsible for the performance of all inspection requirements as specif
16、ied herein, Except as otherwise specified, the supplier may utilize his own facilities or any commercial laboratory acceptable to the Government. The Government reserves the 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-_ _- MIL-S-L25b I3 W 99799
17、0b OLl27OI O MIL-S- 81256(;JP) right to perform any of the inspections set forth in the specification where such inspections are deemed necessary to assure supplies and services conform to prescribed requirements. 4.2 Classification of inspections. Inspection of the fabric shall be classified as fol
18、lows: a. Preproduction inspection (see 4.4) b. Quality conformance inspection (see 4.5) 4.3 Sampling 4.3.1 Preproduction sample, A preproduction sample of sufficient material shall be used to make two specimens for each of the tests. Each sample, manufactured in accordance with3.1, shall be subjecte
19、d to the pre- production tests detailed in 4.4 at an activity designated by the procuring activity, Further production of the impregnated fabric by the supplier, prior to approval of the preproduction sample, shall be at the suppliers risk. 4.3.2 Quality conformance inspection sampling. Unless other
20、wise specified, sufficient material shall be taken from each lot to perform the tests as specified in 4.5. 4.3.3 inspection lot. An inspection lot of the impregnated silicafabric shall consist of all material presented for acceptance at one time and pro- duced in a single manufacturing batch under h
21、omogeneous conditions of manufacture. 4.4 Preproduction inspection. The preproduction sample shall satis - factorily pass the quality conformance inspections detailed in 4.5. In addition, the following test shall be performed. 4.4.1 Silica purity test. This test shall be run prior to the material be
22、ing added to the resin, Weigh a platinum crucible with cover to the nearest 0.1 milligram (mg) (weight A). Place about 0.5O-gram sample into the crucible, cover, and ignite for 10 minutes under the full flame of a 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license
23、 from IHS-,-,-MIL-S-L25b 33 m 7979706 0427037 2 = Meeker burner. After ignition, cool in a desiccator and weigh with cover on to the nearest 0.1 mg (weight B). Add 5 drops of 1:1 sulfuric acid and sufficient hydrofluoric acid (47-percent reagent grade) to fill the crucible to about 50 percent capaci
24、ty. Place crucible in sand bath and evaporate slowly (to prevent spattering) under a hood until fuming ceases. Again add 5 drops of 1:l sulfuric acid and sufficient hydrofluoric acid (47. percent reagent grade) to fill the crucible to about 50-percent capacity. Place crucible in sand bath and evapor
25、ate slowly (to prevent spattering) under a hood until fuming ceases. After the second evaporation, ignite crucible for 10 minutes under the full flame of the Meeker burner, Cool in desiccator and weigh with cover on to the nearest 0,l mg (weight C). Calculations : Weight B - Weight C Weight B - Weig
26、ht A X 100 Percent silica (SiO2) = 4.4.2 Specific gravity test. From each sample, mold test specimens of the impregnated fabric at 2000 5 100 psi and 310 f 5 degrees Fahrenheit ( F) for 6 minutes. Determine the specific gravity in accordance with ASTM D 792-60. 4.4.3 Compressive strength test. From
27、each sample, mold test specimens of the impregnated fabric at 6000 f 100 psi and 310 f 5 degrees F for 10 minutes. Determine the compressive strength in accordance with ASTM D 695-54. 4.4,4 Tensile strength test. From each sample, mold test specimens of the impregnated fabric at 4000 f 100 psi and 3
28、10 I 5 degrees F for 6 minutes. Determine the tensile strength in accordance with ASTM D 651-48. 4.5 Quality conformance inspection 4.5.1 Visual examination. Visually examine all containers in the lot to determine compliance with 3.5 and Section 5. 5 Provided by IHSNot for ResaleNo reproduction or n
29、etworking permitted without license from IHS-,-,-MIL-S-L25b L3 m 77733Ob 0927020 3 m MIL-S-81256 (WP) 4,5.2 Volatiles and resin solids content test. The volatiles and resin solids content of the uncured impregnated fabric shall be determined by weighing 5 to 6 grams of sample to the nearest milligra
30、m (0.001 mg) into a previously fired (1450 degrees F) and tared crucible, Designate this weight as W1“ Condition the sample and crucible in a circulating-air oven at 325 f 5 degrees F for 20 minutes; remove, cool in a desiccator and reweigh to obtain the sample weight. Designate this weight as W20 U
31、sing a tripod, clay triangle, and Bunsen burner, care- fully heat this same sample and crucible to eliminate combustible material and carbonize resin. When carbonization is complete,place the sample and crucible in the muffle furnace. Condition at 1450 f 10 degrees F for 3 hours; remove, cool in des
32、iccator and reweigh to obtain the final weight. Designate this weight as W3* Calculations : A, Volatile content at given conditions w1 -w2 x100 Percent volatiies = where: W1 = Original sample weight W2 = Sample weight after 20 minutes at 325 f 5 degrees F B. Resin solids content WS -w3 x100 Percent
33、resin solids = where: W2 = Sample weight after 20 minutes at 325 f 5 degrees F W3 = Sample weight after 20 minutes at 325 f 5 degrees F and and 3 hours at 1450 f 10 degrees F 4.5.3 Flow test, All material shall be brought to room temperature 6 Provided by IHSNot for ResaleNo reproduction or networki
34、ng permitted without license from IHS-,-,-B MIL-S-125b 13 W 77777Ob 0427021 O W MIL-S- 81256(TclP) a before starting the flow test. Weigh a sample of approximately 50 grams to the nearest 0.01 gram. Designate this as W1. The sample shall be preformed in a 2-3/4 f 1/16 inch diameter mold under 5000 i
35、 25 psi pressure. Allow the preform to dwell 2-3 seconds. Place the sample into mold and close under a pressure of 2000 f 25 psi at a temperature of 300 f 5 degrees F for 5-6 minutes. The closing time shall be 6-7 seconds. Take the sample from the mold and remove the sprue carefully and cut off the
36、first measurable 1.00 inch adjoining the disc. Weigh the disc to the nearest 0.01 gram and designate this as W2. w1 -w2 x100 Percent flow = w1 4.6 Acceptance criteria 4.6.1 Preproduction. Failure of any test to meet the requirements of this specification shall be cause or rejection of the lot, 4,6.2
37、 Quality conformance. Failure of any sample to meet any require- ment of this specification shall be cause for rejection of the lot. 5. PREPARATION FOR DELTVERY 5.1 Preservation, packaging and packing. Unless otherwise specified in the contract or order, minimum requirements for preservation, packag
38、ing and packing shall be in accordance with BAL-P-116, Method III. 5.2 Marking. Each container shall be marked in accordance with MU-STD-129. Marking shall include, but not be limited to, the following information: a. Manufacturers name and location b. Material trade name c. Net weight or volume d.
39、Lot number, batch number and date of manufacture e. Shelf life or storage limitations f, Number and revision letter of this specificatim 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-_I_ MIL-S-1256 13 = 7977706 0427022 2 W . u 6. NOTES 6.1 Intend
40、ed use. The material purchased in accordance with this specification is intended to be used as a component of 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. NLinimum lot siz, if applicable c. Whether preproduction sample is required d. Place of delivery e. Size of container f. Request for test data 8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
