1、MIL-C-537A 83 I 7994906 0373263 2 M MIL-C-5 39A (OS) 22 December 1976 SUPERSEDING 28 November 1947 JAN - C- 5 39 MILITARY SPECIFICATION CLOTH, SILK, CARTRIDGE-BAG 172is specification is approved for use by the Naval Sea Systems Command, Department of the Navy, and ts available for use by all the dep
2、artments and agencies of the Department of Defense. 1. SCOPE 1.1 Scope, This specification covers one grade of silk cartridge- bag cloth, (See 6.1.) 1.2 Classification. Silk cartridge-bag cloth shall be of the following i classes, as specified (see 6.2) : Class A-Breaking strength 165 pounds per squ
3、are inch (minimum) Class B-Breaking strength 125 pounds per square inch (minimum) Class C-Breaking strength 90 pounds per square inch (minimum) Glass D-Breaking strength 60 pounds per square inch (minimum) Class E-Breaking strength 30 pounds per square inch (minimum) Class F-Breaking strength 85 pou
4、nds per square inch (minimum) Class G-Breaking strength 25 pounds per square inch (minimum) 2. APPLICABLE DOCUMENTS 2.1 Issues of documents. The following documents of the issues in effect on date of invitation for bids or request for proposals form a part of this specification to the extent specifi
5、ed herein. of conflict between this Specification and other documents referenced herein, requirements of this specification shall apply. In the event a Beneficial comments (recommendations, additions, deletions, and any pertinent data which may be of use in improving this document should be addresse
6、d to: Naval Ordnance Station, Indian Head, Md. 20640, by using the self-addressed Standardization Document improvement Proposai (DD Form 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-C-5
7、39A 3 W 9999706 0371i262 4 W MIL-C-5 39A(OS) SPECIFICATIONS Federal PPP - B- 59 1 PPP-B-601 PPP-B-621 Mi 1 it arv Boxes, Fiberboard, Wood-Cleated Boxes, Wood, Cleated-Plywood Boxes, Wood, Nailed and Lock-Corner NI L- P - 1 30 Paper, Wrapping, Laminated and Creped STANDARDS Feder al FED-STD-191 Text
8、i le Test Me thods FED - STD - 7 5 1 Stitch, Seam and Stitching Mi 1 it ary MIL- STD - 129 Marking for Shipment and Storage (Copies of specifications and standards required by contractors in connection with specific procurement functions should be obtained from the procuring activity or as directed
9、by the contracting officer.) 3. REQUI REEENTS 3.1 Material. The cloth chal be manufactured from pure silk without the admixture of any other material whatever, except the amount of sizing absolutely necessary to facilitate weaving. before shall be used-in the manufacture of cartridge-bag cloth. Only
10、 silk not used 3.2 Fiber. The fiber shall be pure silk. 3.3 Weave. Unless otherwise specified, the weave shall be a plain single or a double basket weave. 3.4 Slippage value, The slippage value of the cloth shall be not less than 60 in either direction of the filling or the direction of the warp. I
11、a Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-C-537A 3 7797706 0371263 h I 3.5 Stretch. The stretch of the cloth shall be not greater than 12.5 percent in either the direction of the filling or the direction of the warp. 3.6 Width, The width
12、of the cloth shall be as specified in the contract A tolerance in width of rt00,25 inch will be permitted, or order (see 6.2). , 3.7 Objectionable sizing. The character and quality of the sizing materials (see 6.3) shall be such that there is not indication of smoldering when the cloth is ignited su
13、fficiently to give a good flame and then extinguished. The cloth shall pass the objective sizing test prescribed in 4,3.6. 3.8 Ether extract. The ether extract shall be not greater than 10 percent. 3.9 Acidity or alkalinity. 3,9,1 pH of water extract, The pH of water extract of the cloth shall be no
14、t less than 4.4 nor greater than 9,7. 3.9.2 Organic acidity or alkalinity, The water extract of the cloth shall show not greater than 0.1 percent acidity, calculated as acetic acid, nor greater than 0.1 percent alkalinity, calculated as sodium car- bonate, 3.10 Ash. The ash content shall be not grea
15、ter than 0.2 percent, - 3.11 Weight. Unless otherwise specified, the weight of the cloth shall comform to the requirements specified in table I. 3.12 Breaking strength. Unless otherwise specified, the breaking strength of the cloth shall conform to the requirements specified in table II, 3.13 Workma
16、nship. The cloth shall be woven so as to be close and uniform and shall be free from defects which might affect the service- ability 3 , Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-e I MIL-C-537A 3 = 7774906 03712b4 B MI L-C- 5 39A( OS) , TABLE I
17、. Weight. Pounds per inch, either direction, minimum Class 165 125 90 60 30 85 25 .TABLE II, Breaking strength. 1 I Class I Ounces per Minimum =I Maximum 14.0 10 .o 7.0 6 ,O 5.0 - 6.5 4.0 4, QUALITY ASSURANCE PROVISIONS 4,l Responsibility fQr inspection, Unless otherwise specified in the contract or
18、 purchase ordr, the contractor is responsible for the perform- ance of all inspection requirements, as specified herein. Except as otherwise specified in the contract or order, the contractor may use his own or any other facilities suitable for the performance of the inspection requirements Specifie
19、d herein, unless 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 supplies and services conform to prescribed requirements. 4.2 Oualitv conformance insnection. 4.2.
20、1 Size of lot. Unless otherwise Specified, a lot shall consist of each 100,000 yards, or a fraction thereof, of cloth of one class sub- mitted for inspection at the same time, I Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-C-537A 3 m 7779706 0
21、371265 T m MI L-C-539A( OS) I i 4,2,2 Sampling, Ten percent, but in no case more than 10, of the bales or boxes comprising the lot shall be selected so as to be representative of the lot. One bolt of cloth shall be removed from each selected bale or box, at least 50 feet unrolled, and a sample of 2
22、running yards cut from the bolt. which it was taken can be identified. A composite sample of the lot, consisting of approximately 1 yard from each of the primary samples, shalLbe made. All samples shall be labeled, giving the name of the material, class, manufacturer, plant, contract or order number
23、, and the number of yards in the lot. composite sample representative of the lot. be held for possible future examination should the composite sample fail to meet the requirements of this specification, Each sample shall be labeled so that the bale or box from All acceptance tests shall be made on t
24、he The primary samples shall 4.3 Test methods. 4.3.1 Fiber. Tests shall be made in accordance with the following: Unravel warp and fill threads 1 to 2 inches in length - from each piece of cloth comprising the sample, (mg) beaker or test tube containing 10 ml of boiling 17.5 percent sodium hydroxide
25、 solution, Note whether solution of the fibers occurs, Immerse another 5-mg portion of the fibers in a 30-ml beaker or test tube con- taining 10-ml of 95 to 96 percent sulfuric acid solution at a temperature of 25O to 30“ C, and agitate the mixture for 5 minutes. solution of the fibers occurs. Consi
26、der the material to be silk, if the . fibers dissolve in both alkali and acid. of a few fine short hairlike fibers to dissolve. Immerse a 50-milligram Note whether In testing disregard the failure 4.3.2 Weave, Determine the weave by visual examination. 4.3.3 Slippage value, - Cut 10 test specimens a
27、s directed in FED-STD-191 and supplement thereto for use in determining the breaking strength, except that each specimen shall be 16 inches in length, Use the five specimens having the short dimension parallel to the warn threads for the determination of sion parallel to the filling threads for the
28、determination of fill slippage, fied in FED-STD-191 for use in- the determination of elongation. the distance between the jaws of the testing machine to 3 inches, a test specimen back on itself so that the distance from the fold to one edge, parallel to the short dimension, measures approximately 5
29、inches and to the other, at least 10 inches, Take care to haye the fold parallel to the crosswise yarns in the specimen. At 0.38 inch from the fold sew a seam parallel to the crosswise yarns of the specimen. the type designated as 301-SSa-1 by FED-STD-191 (seam SSa-1 formed with 1 row of stitch type
30、 301). Use 1 row of stitch type 301, 12 stitches per inch to make the seam. a heavy silk thread of sufficient strength so that it will not break when slippage and the five having the short dimen- For making this test, use a machine of the standard type speci- Adjust Fold . Use a seam of . In making
31、the seam use a suitable needle and ! - 5 * Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-C-539A 3 W 9999906 03712bb 1 . MIL-C-S39A(OS) the seam is tested for elongation as directed below (a No, 21 needle and comercial grade H (14-pound) waterpr
32、oofed silk, fishine line thread with a left-hand machine twist has been found satisfactory). specimen, with the 10-inch portion uppermost, symmetrically in the upper jaws so that the long dimension of the 10-inch portion of the specimen is parallel to the direction of application of the load, men i?
33、 the upper jaws so that the seam is at least 3 inches below the lower jaws. Attach a 6-ounce clamp to the specimen at a point beneath the lower jaws so that a uniform tension of the amount is applied to the specimen, and clamp the lower jaws, taking care to grip the same yarns in the lower jaws as a
34、re gripped in the upper jaws, The clamp can be assembled from (a) a metal photographic film clip, (b) a brass or steel rod 6 inches long and 3/16 inch in diameter, and (c) equal brass or steel weights which are sufficient to bring the total weight of the assembly to 6 ounces, up to the breaking stre
35、ngth of the specimen, the stretch being indicated in inches by the vertical component and the tension being indicated in pounds by the horizontal component. Start the machine and allow it to apply tension until the specimen breaks, as the fabric-stretch curve, the machine so that the seam is in a po
36、sition parallel to the jaws and midway between the upper and lower jaws, Clamp the specimen in the jaws, applying tension by means of the 6-ounce clamp, as directed above, before tightening the lower jaws, record of this test will be made on the same chart and start at the same point, until either t
37、he cloth breaks or the segn fails. Designate this graphic record as the seam-st-retch curve, distance between the seam-stretch curve and the fabric-stretch curye is equal to the sum of (a) the vertical distance between these curyes equiva- lent to 0.25 inch on. the cloth, Place the test Clamp the sp
38、eci- Arrange the apparatus to obtain a tension-stretch curve Designate this graphic record Insert the same specimen in the jaws of Arrange the apparatus so that the graphic Start the machine and allow tension to be applied to the specimen Note the tension at which the vertical Calculate the slippage
39、 value as follows: 100A Slippage value = 7 where A = tension at which the difference between the seam-stretch curve and the fabric-stretch curve is 0,25 inch plus the difference between these curves inside, 7 inches high and 4 inches in diameter. Seal the vessel with a lid lined with nonconducting m
40、aterial having three holes, one at the center for a thermometer, and two diametrically opposite near the rim. receive copner tubes of 1/2-inch diameter so arranged that when the lid is in place, one tub2 enters the oven to a depth of 6 inches while the other rises to an equal height above the lid, T
41、hese tubes assure a con-. stant draft of air through the instrument, with the central hole, a cylinder of wire gauze, 6 inches long and 1-1/2 These holes On a common vertical axis t inches in diameter, shall be supported within the oven, ir .r, 7 a - Provided by IHSNot for ResaleNo reproduction or n
42、etworking permitted without license from IHS-,-,-MIL-C-537A 3 7777706 03712b 5 a MI L-C- 5 39A (OS) AIR VENT Figure 1. Mackey test apparatus for use in sizing test) 4.3.6.2 Procedure. to 1/2-inch squares within the-wire cylinder, compressing it to occupy the upper 4-1/2 inches, the center of this ma
43、ss, duce the cylinder and thermometer, allowing the latter to protrude through a cork placed in the central hole in the lid: Allow the water to boil and record the temperature at frequent intervals for 1-1/2 hours, Con- sider the.materia1 to fail with respect to the presence of objectionable sizing
44、if the fabric attains a temperature of 100“ C within 1 hour, or if it reaches a temperature of 120“ C, within 1-1/2 hours. Place 12 k 1 gram of the sample cut into 1/4-inch Arrang6 &he thermometer so that the bulb is in Heat the Water to the boiling point then intro- Provided by IHSNot for ResaleNo
45、reproduction or networking permitted without license from IHS-,-,- - 7 MIL-C-539A 3 7779706 0373267 7 MI L-C- 5 39A (OS) 4,3,7 Ether extract. Cut 10 pieces of cloth, weighing approximately 0.5 gram each, from various portions of the sample. Weigh these pieces together and transfer them to the extrac
46、tion chamber of a Soxhlet extracsio tion apparatus having ground-glass connections. Assemble the extraction chamber to a tared receiving flask and transfer ether to the extraction chamber until the sample is covered and the ether siphons over the flask, Add approximately 25 ml more ether to the extr
47、action chamber, assemble a condenser to it, and place the assembled apparatus on a steam bath, Allow the extraction to proceed for 1.5 hours, Discontinue heating at a time when the ether content of the extraction chamber is nearly suf- ficient to cause the ether to siphon over the receiving flask. f
48、lask, containing the oily ether extract, on a steam bath until the ether is removed, cool in a desiccator, and weigh, Calculate the weight of residue to per- cent ether extract. Heat the Dry the flask and residue in an oven at 100“ C for 1 hour, 4.3.8 Acidity or alkalinity, 4,3,8.1 pH or water extra
49、ct, Cut 10 pieces of cloth, weighing approx- imately 0.5 kram each, from yarious portions of the samDle. Combine - these pieces, weigh, and transfer to-a 250-ml.beaker. freshly boiled, distilled water to the beaker, cover with a watch glass, and boil the water gently for 30 minutes. becomes less than one-half the original amount during the boiling period, add sufficient boiling distilled water to restore it to the original volu
