1、MI L- L-85490 (AS ) 6 October 1981 MILITARY SPECIFICATION LINER, CASE, ROCKET MOTOR This specification is approvedfor use by the Naval Air Systems Command, Department of the Navy, and is available for use by all Departments and Agencies of the Department of Defense. 1. SCOPE. 1.1 Scope. This specifi
2、cation establishes the requirements for rocket 2. APPLICABLE DOCUMENTS. 2.1 motor case 1 iner material. Issues of documents. The following documents of the issue in effect on date of invitation for bids or request for proposal form a part of this specification to the extent specified herein. SPEC1 F
3、I CATIONS MI LI TARY MIL-C-85496 MIL-1-85492 MIL-H-85497 MIL-C-85498 Carbon Black. Imine Curing/Bonding Agents. Hydroxyl -Terminated Polybutadi ene. Curing Agent, Dimeryl-diisocyanate and Isophorone di-isocyanate. Beneficial comments (recomendations, addi tions , del eti ons) and any pertinent data
4、which may be of use in improving this document shoul d be addressed to : Commanding Off i Cer , Naval Air Engineering Center, Engi neeri ng Specifications and Standards Department (ESSD) Code 93, Lakehurst, NJ 08733, by using the self-addressed Stan- dardization Document Improvement Proposal (DD For
5、m 1426) appearing at the end of this document or by letter. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. - - MIL-L-85470 68 7777906 0123571 O m MI L- L-854 90 (AS) t STANDARDS MILITARY MIL-STD-2126 Reduced Smoke Rocket Motor Processing and Test
6、Procedures. (Copies of specifications, standards, drawings and pub1 ications required by contractors in connection with specified procurement functions should be obtained from the procuring activity or as directed by the contracting officer.) 2.2 Other publications. The following documents form a pa
7、rt of this specification to the extent specified herein. the issue in effect on date of invitation for bids or request for proposal shall apply. Unless otherwise indicated, STANDARDS American Society for Testing and Materials (ASTM) ASTM D 5 ASTM D 41 2 Penetration of Bituminous Materials, Test for.
8、 Standard Methods of Tension Testing of Rubber . I (Applications for copies should be addressed to the American Society for Testing and Materials, 1916 Race Street, Philadelphia, Pennsylvania 191 03. ) 3. REQUIREMENTS. 3.1 Formulation. Formulation of the liner shall be in accordance with Table I. 3.
9、2 Precure time. The liner shall exhibit a penetration of 12.5 millimeters ( see 4.3.1) within 12 to 48 hours of curing at 60 to 66 degrees Celsius (OC). 3.3 Tensile properties. The liner shall possess minimum tensile properties conforming to Table II when tested at 25 53C. 3.4 Weighing accuracy. Eac
10、h liner ingredient shall be weighed to 0.3 of one percent of the weight requirements calculated from the weight percent specified. 2 -, Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-L-5490 68 9 9999906 0323592 2 MI L-L-85490( AS) 3.5 Toxic pro
11、ducts and safety. Safety regulations and guide- lines applicable to the use of the liner should be complied with to preclude personal injury and damage to equipment and facilities. 3.6 Workmanship. The liner shall be homogeneous, of consistent high quality, and free from visible contamination. TABLE
12、 I. Liner formulation. Hydroxyl -terminated po 1 y bu tad i ene Curing agent , di i socyanate Imi ne curi ng/ bonding agent Carbon black Specification MIL-H-85497 Type 11, Class I MIL-C-85498, Type 1 MIL-1-85492, Type II MIL-C-85496 Nomi na1 Weight Ratio 78 - l-73 I 1 Weight, % 2/ 64.0 k5.5 - 2/ 6.0
13、 k0.5 - 2/ 30 55 - I I The NC0:OH ratio may be adjusted from a nominal value of 1.2:1 to optimize tensile, bond, and precure time. g/ The specified weight variation shown is allowed for viscosity control. TABLE II. Liner tensile properties. Property Minimum Maximum Stress, psi Strain at break, perce
14、nt Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. MIL-L-85470 68 9777706 0323573 4 = MIL-L-85490( AS) 4. QUALITY ASSURANCE PROVISIONS. 4.1 Responsibility for inspectton. Unless otherwise specified in the cgntract or purchase order (see 6.2.11, the
15、 contractor is responsible for the performance of al 1 inspection requirements as specified herein. Except as otherwise specified in the contract or purchase order, the contractor may use his own or any other facilities suitable for the performance of the inspection requirements specified herein, un
16、less disapproved by the Government. The Government reserves the right to perform any of the inspections set forth in this specification where such inspections are deemed necessary to assure that supplies and servi ces conform to prescribed requirements. 4.2 Classification of tests. Inspection and te
17、sting of the liner shall be classified as follows: a. Standardization tests (see 4.2.1). b. Quality conformance inspections (see 4.2.2). 4.2.1 Standardization tests. At least one subscale mix of liner shall be manufactured for each new lot of raw material except carbon black (only required when supp
18、lier of carbon black is changed). shall be of sufficient size to perform standardization tests and shall be manufactured in accordance with MIL-STD-2126, Method III. Standard- ization tests shall consist of the following: The mix a. Precure time (see 4.3.1). b. Qual i ty conformance inspections (see
19、 4.2.2). 4.2.2 Quality conformance inspections. Quality conformance inspections shall consist of the following for each production mix of liner. a. Visual inspection (see 4.5). b. Tensile properties (see 4.3.2). 4.2.3 Acceptance criteria. Failure of any sample to pass all the requirements specified
20、herein shall cause rejection of the lot repre- sented. 4.3 Test methods. Tests shall be performed using apparatus, reagents, and procedures specified herein. or procedures shall require prior written approval of the procuring activity. The use of alternate apparatus, reagents, -. /- CI Provided by I
21、HSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-L-85970 68 77777Ob 0323574 b 4.3.1 Precure time. A container, approximately 3 ounces in sire, shall be filled to approximately 75 percent capacity with a sample of the lingr and shall be placed in an oven whose
22、temperature is 60 to 66OC. with ASW D 5, except that the moving load (including needle) shall be 50 grams, the penetration time shall be 30 seconds and the specimen temperature shall be 60 to 66OC. Penetration tests shall be made a sufficient number of times to plot a curye of penetration versus cur
23、e time. Prom the curve, the next full hour (after 12.5 millimeters penetration 3s reached) shall be reported as the precure time. A peuetration test shall be performed on the sample in accordance I 4.3.2 Tensile properties. 4.3.2.1 Preparation of sample sheet. A sample of liner shall be poured into
24、a suitable open, release coated, mold. Enough molds shall be prepared to furnish aminimum of five specimens for testing. The -_ mold shall be cured for 168 +24 hours at a temperature of 77 +6“C. The sheet shall be removed from the mold, dusted with talc, and conditioned for a minimum of 4 hours at 2
25、5 53C imnediately prior to testing. 4.3.2.2 Apparatus. a. Die Type C (all items shall comply with ASTM D 412). b. Thickness gage. 4.3.2.3 Procedures. 4.3.2.3.1 Maximum stress. Maximum stress shall be determined in accordance with ASTM D 412. Calculation: Lb Maximum stress, psi = rw ., Where: Lb = lo
26、ad at break, pounds T = thickness of necked down section, inches W = width of necked down section, inches Report the maximum stress to the nearest integer. 4i3.2.3.2 Strain at break. Strain at break shall be determined in accordance with ASTMD 412. 5 Provided by IHSNot for ResaleNo reproduction or n
27、etworking permitted without license from IHS-,-,-MIL-L-85470-68 = 9999906 0323595 B MI L-L-854 90 (AS ) Cal cul ati on : (D - Do) x 100 Strain at break, % = DO Gihere: Do = original distance between bench marks, inches D = distance between bench marks at break, inches Report the strain at break to t
28、he nearest integer. 4.4 Records. Certification and test data shall be prepared as required by the procurlng activity (see 6.2.2). 4.5 Visual inspection. Verification of workmanship shall be determined by visual inspection (see 3.6). 5. PACKAGING. This section is not applicable to this specification.
29、 6. NOTES AND CONCLUDING MATERIAL. 6.1 Intended use. The intended use of the material described herein is as liner or insulation for rocket motor cases. 6.2 Ordering data. 6.2.1 Procurement requirements. Procurement documents should specify the following: a. Title, number, and date of this specifica
30、tion. b. Responsibility for inspection and inspection facilities, if different than 4.1. 6.2.2 Data requirements. When this specification is used in a pro- curement which incorporates a Contract Data Requirements List (DD Form 1423) and invokes the provisions of 7-104.9(n) of the Defense Acquisition
31、 Regulations (DAR), the data requirements identified below will be developed as specified by an approved Data Item Description (DID) (DD Form 1664) and delivered in accordance with the approved DD Form 1423 incorporated into the contract. When the provisions of DAR-7-104.9(n) are not invoked, the da
32、ta specified below will be delivered by the contractor in accordance with the contract requirements. specification is cited iti the following paragraphs: Del iverabl e data required by this 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-L-8547
33、0 68 = 7777706 0323576 T W - MI L- L-85490 (AS) Paragraph 4.4 Data Requirement Applicable DID Cert i fi cat i on Test data DI -T-4024 UD1 -232648 (Copies of DIDs required by the contractors in connection with specific procurement functions should be obtained from the procuring activity or as directed by the contracting officer.) Preparing activity: (Project 681 0-NB22) Navy - AS OuS. GOVERNMENT PRINTING OFFICE: 1981-505-022/8513 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
