1、b -c -. 26 O ct 83 - L MIL-S-27332B 16 779770b 0425323 9 W MIL-S-7332B(UCAF) SUPERSEDING MIL-S-27332A(USAF) 12 January 1966 1. SCOPE MILITARY SPECIFICATION SEAT CUSHION INSERT, POLYURETHANE FOAM, PLASTIC, GENERAL SPECIFICATION FOR This specification is approved for use by the Department of the Air F
2、orce, and is available for use by all Depart- ments and Agencies of the Department of Defense, * 1.1 Scope. This specification covers the general requirements for plastic, open-celled, prefoamed, uncored, polyether polyurethane seat cushion inserts. 2. APPLICABLE DOCUMENTS 2.1 Government documents,
3、* 2.1.1 Specifications and standards. Unless otherwise specified (see 6.21, the following specifications and standards of the issue listed in that issueof the Department of Defense Index of Specifications and Standards (DODISC) speci- fied in the solicitation, form a part of this specification to th
4、e extent specified herein. SPECIFICATIONS FEDERAL PPP-B-601 PPP-3-636 MI LI TARY Boxes, Wood , Cleated-Plyqood Box, Shipping, Fiberboard MI L-P-116 Preservation, Methods of STANDARDS &II LI TARY MIL-STD-129 MIL-STD-13 O MIL-STD-143 MIL-STD-794 Marking for Shipment and Storage Identification Marking
5、of U.S. Military Property Standards and Specifications, Order of Precedence for the Selection of Part and Equipment, Procedures for Packaging and Packing additions, deletions) and any pertinen ALC/MMEDO, Kelly AFB, Texas 78241 by Document Improvement Proposal this document should be addressed to: 1
6、(DD Form 1426) appearing at the end of this document or by letter. FSC 1660 Obtained From GLOBAL ENGINEERING DOCUMENTS 2625 So.Hickory St. Santa Ana, CA 92707 . 4714)540.9870: (8001854-7179 _- . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-2
7、7332B Lb 777770b 0425324 O I (Copies of specifications and standards required by manufacturers in con- nection with specific acquisition functions should be obtained from the con- tracting activity or as directed by the contracting officer.) 2.1.2 Other Government documents, drawings, and publicatio
8、ns. The follow- ing other Government documents f0rm.a part of this specifications to the extent specified herein. NATIONAL BUREAU OF STANDARDS H4-1 - Federal Supply Code for Manufacturers. (Application for copies should be addressed to the Superintendent of Docu- ments, Government Printing Office, W
9、ashington, D.C. 20402.) AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM) ASTM D 3951-82 - Packaging, Commercial - 29 Jan 82 (Application for copies of ASTM publications should be addressed to the American Soceity for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103.) 2.1.3 Order of p
10、recedence. In the event of a conflict between the text of this specification and the references cited herein, the text of this specifi- cation shall take precedence. 3, REQUIREMENTS 3.1 First article. This specification makes provisions for first article testing 3.2 Selection of specifications and s
11、tandards, Specifications and stand- ards for necessary commodities and services not specified herein shall be selected in accordance with MIL-STD-143. 3.3 Materials. The materials used in the manufacture of polyurethane foam for seat cushion inserts shall be high quality, uncored, open-celled, polye
12、ther polyurethane. The material shall be prefoamed and cut to the required shape. 3.4 Configuration. The seat cushion inserts shall have the dimensions. and dimensional tolerances specified on the applicable drawings. 3.5 Performance. 3.5.1 Load deflection characteristics (50 square inch indentor fo
13、ot). Deflection by means of a 50 square inch deflector foot shall produce the values specified in-tab.le I, seat cushion insert. up, without the use of cement, to a height-of 4 +1/8 inches. seat cushion insert has dimensions less than 15 by 15 inches or a height greater than 4 ti/8 inches, a test sa
14、mple of the seat cushion insert material having dimensiob of 18 by 18 by 4 - +1/8 inches shall be submitted for tests. .The size of the test sample shall consist of the entire Samples less than 4 t1/8 inches in height shall be plied If the entire Provided by IHSNot for ResaleNo reproduction or netwo
15、rking permitted without license from IHS-,-,-MIL-S-27332B Ib 9999906 0425325 2 MIL-S-2 7332B (USAF) TABLE I. Load deflection characteristics requirements (50 square ,inch indentor foot). Load I I Percent Deflection I 25 50 65 75 80 85 40 2 5 pounds 60 2 6 pounds 80 t 8 pounds 130 2 20 pounds 165 2 4
16、0 pounds 180 pounds minimum 3.5.2 Density. The density of the polyurethane shall be 1.6 - +0.2 pounds/ cubic feet. 3.5.3 Tensile strength. The tensile. strength of the seat cushion insert material shall have a value of 12 pounds per square inch minimum. 3.5.4 Elongation, insert material shall be 180
17、 percent minimum. The value of the ultimate percent elongation for the 3.5.5 Compression set. The percent loss of original height shall be not more than 15 percent. 3.5.6 Air oven aging. The allowable percent change in load deflection values after air oven aging shall be - +10 percent maximum, 3.5.7
18、 Humidity aging. 3.5.7.1 After humidity aging, the percent loss of original height shall be not more than 15 percent. 3,5.7,2 After humidity aging, the percent change in load deflection characteristics for 25, 50, 65, 75, 80, and 85 percent deflections shall be not more than 25 percent for the 50 sq
19、uare inch indentor foot test, 3.5.8 Tear resistance. The tear resistance of the insert material shall be not less than 1.5 pounds per inch for all specimens. 3.6 ia The following information shall be sten- ciled on each seat cushion insert in accordance with MIL-STD-130: a, Title and number of this
20、specification. b. Contract number and date. c. . Stock number. d. Manufacturers name (if desired, the manufacturers internal desig- nations and trade name may be included). e, Applicable drawing number, 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,
21、-,-MIL-S-27332B Lb W 9999906 042512b 4 m MIL-S-27332B( USAF) 4 n The identification marking ink shall be nontoxic, waterproof., fade resistant, and resistant to obliteration in normal usage. Letter and numeral sizes shall be 1/2 inch. The identification marking shall be on the top or bottom surface
22、of the seat cushion insert, located at the discretion of the manufacturer, 3,7 Workmanship, The seat cushion inserts shall be constructed in a thoroughly workmanlike manner, that might affect their appearance or functionability. They shall be clean and free from any defects 4, QUALITY ASSURANCE PROV
23、ISIONS 9: 4.1 Responsibility for inspection. Unless otherwise specified in the con- tract or purchase order, the contractor is responsible for the performance of all inspection requirements as specified herein. Except as otherwise specified in the contract or purchase order, the contractor may use h
24、is own or any other facilities suitable for the performance of the inspection requirements speci- fied herein, unless disapproved by the Government. The Government reserves the right to perform any of the inspections set forth in the specification where such inspections are deemed necessary to assur
25、e supplies and services conform to prescribed requirements. 4,2 Classification of tests. The inspection and testing of seat cushion inserts shall be classified as follows: a, First article tests (see 4.4) b. Acceptance tests (see 4.5) 4.3 Test: conditions, 4.3.1 Atmospheric conditions. Unless otherw
26、ise specified, all OestO required by this specification shall be made at a temperature of 73 a relative humidity of 50 22 percent. - +2 F and 4.3.2 Test specimens. Test specimens shall consist of the entire seat cushion inserts or samples, as specified, which shall be cut from seat cushion inserts.
27、from the same seat cushion insert. Unless otherwise specified, height of the specimens shall be 4 2118 inches. 4.4 First article testing. 4.4.1 First article test samples. The contractor shall subject specimens No more than one test sample for each specified test shall be cut to the first article te
28、sts specified in 4,4.3. shall be required for the load deflection characteristics tests Three seat cushion inserts 4.4.2 First article test samples for the procuring activity. The contrac- tor shall submit three seat cushion inserts to the procuring activity. 4.4.3 First article tests. First article
29、 tests shall consist of all the 4.5 Acceptance tests. Acceptance tests shall consist of: tests described under 4.6. a. Individual tests. b, Sampling plan and tests. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-S-27332B Lb m 777770b 0425327 h
30、m MIL-S-27332B(USAF) 4.5.1 Individual tests. Each seat cushion insert shall be subjected to the examination of product test as described under 4:6. 4.5.2 Samplinp plan and tests. 4.5.2.1 E. A lot shall consist of seat cushion inserts manufactured under essentially the same conditions and submitted f
31、or acceptance at sub- stantially the same time. 4.5.2.2 Sampling tests. Four seat cushion inserts shall be selected at random from each lot of one hundred inserts or fraction thereof and subjected to the load deflection characteristics tests described under 4.6. 4.5.2.2.1 Rejection and retest. When
32、one or more items from a lot fail to meet the specification, acceptance of all items in the lot shall be withheld until the extent and cause of failure are determined. The contractor shall explain fully to the Government representative the cause of failure and the action taken to preclude recurrence
33、. Af-ter corrections have been made, all necessary tests shall be repeated. 4.5.2.2.2 Individual tests may continue. For production reasons, individ- ual tests may be continued pending the investigation of a sampling test fail- ure, until it is determined that all items meet all the requirements of
34、the speci- f ication, Final acceptance of the entire lot or lots produced shall not be made 4.5.3 Eefects in items already accepted. The investigation of a test failure could indicate that defects may exist in items already accepted. so, the contractor shall fully advise the procuring activity of al
35、l the defects likely to be found and the method of correcting them. If 4.6 Test methods. 4.6.1 Examination of product. The length, width, and height of seat cushion inserts shall be measured to the nearest 1/16 inch to determine conformance to the dimensions and tolerances specified on the applicabl
36、e drawings. conformance to the requirements of this specification with respect to materials , workmanship, and marking. The seat cushion inserts shall be visually examined to determine 4.6.2 Load deflection characteristics. The following load deflection characteristics tests shall be conducted to de
37、termine compliance with the requirements of 3,5.1 and Table I. 4.6.2.1 Fifty square inch indentor foot. An apparatus having a flat circu- lar indentor foot 50 square inches in area, connected by means of a swivel joint to a load measuring device and mounted in such a manner that the specimen 5 Provi
38、ded by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-273328 Ib 77777Ob OY2512 m MIL-S27332B(USAF) can be deflected at a suitable rate, shall be used for this test, ratus shall be arranged to support the specimen on a level horizontal plate perforated wit
39、h 0.25 inch holes on 0.75 inch centers to allow for rapid escape of air during the test. The seat cushion insert shall first be twice deflected to 75 25 percent of its original height by using plates or rollers as a means of obtaining the deflection. rest a period of 10 25 minutes, on the supporting
40、 plate of the apparatus and the indentor foot brought into contact with the specimen. The height shall be determined after applying a total preload of 1 pound. The specimen shall then be compressed 25. percent of this height and the final load observed after 1 minute. The same procedure shall be fol
41、lowed for 50, 65, 75, 80 and 85 percent load deflection character- istics, The appa- The specimen shall then be allowed to The specimen shall then be placed in position 4.63 Density, Three representative specimens of regular shape shall be cut from three different seat cushion inserts and tested to
42、determine com- pliance with the requirements of 3.5.2. than 1 cubic inch in volume and shall be free.from surface skin. The volume of the specimens shall be calculated and the specimens weighed on a balance or scale graduated to permit weighings within +i percent of the weight to be measured, be cal
43、culated as follows: The specimens shall be not less The density shall be reported in pounds/cubic feet and shall Density in pounds/cubic feet = Specimen weight in pounds Specimen volume in cubic feet. 4.6.4 Tensile strength. Three test specimens as shown on figure 1 shall The specimens shall be free
44、 from be cut from three different seat cushion inserts and tested to determine compliance with the requirements of 3.5.3. nicks and ragged edges. machine equipped with a dial or scale indicator that will remain at the point of maximum load after rupture. grips shall be 20 +i inches per minute and sh
45、all be uniform at all times. The dumbbell-shaped specimen shall be placed in the grips of the testing machine using care to adjust them symmetrically in order that the tension will be distributed uniformly over the cross section. calculated by dividing the load by the original cross sectional area a
46、nd shall be expressed in pounds per square inch. The tensile test shall be made on a power-driven The rate of travel of the power-driven The tensile stress shall be 4.6.5 Elongation. Elongation measurements shall be made coincident with the tensile strength tests specified in 4.6.4 .to determine com
47、pliance with the requirements of 3.5.4, placed on the 112 inch section of each of the three dumbbell-shaped test specimens specified in 4.6.4. The distance between the two bench marks shall be recorded continuously as the specimen is loaded. The testing machine and rate of travel of the jaws shall b
48、e the same as specified in 4.6,4. Bench marks located 1 inch apart shall be a Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-273328 Lb m 977770b 0425L29 T m MIL- S - 2 7 3 3 2B ( US AF ) TEH/? Tt-sir SPEC/rn# FIGURE 1. Test Specimens 7 Provide
49、d by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I NIL-S-Z7332B 11b 9999906 04251130 b The ultimate elongation shall be calculated by subtracting the original distance between bench marks from the total distance between bench marks at the time of rupture and expressing this difference as a percentage of the original dis tance, 4,6,6 Compression set. Three specimens, with dimensions of 1 by
