Jl-LV 



THE INDIA RUBBER WORLD 



643 



Standard General Methods for Testing Cotton Fabrics. ' 



Serial Designation: D 39—18 T; Issued, 1915; Revised, 1916, 1918. 



Table I. — Tensile Strength Test Methods. 



IThe following general methods are intended to be applica- 

 , ble for testing cotton fabrics. Where a material requires 

 special treatment, specific methodes will be described as 

 they are developed for that material and such special tests shall 

 have precedence over the general method. 



I. CONDITION. 



2. The dry condition of cotton fabric shall be understood to 

 be absolute dryness obtained by placing the material in a venti- 

 lated drying oven maintained at a temperature of 105 to 110 

 degrees C. (221 to 230 degrees F.) and dried to constant 

 weight as determined by two consecutive weighings without 

 removal from the oven, to be taken not less than ten minutes 

 apan, and to show a further loss of not more than 0.1 per 

 cent of the previous weighing. 



3. The standard condition of cotton fabric shall be under- 

 stood to be the condition in which it contains 6.5 per cent of 

 its dr>' weight of moisture. 



II. TEST METHODS. 

 (A) LENGTH. 



4. The length of a roll or piece shall be determined by 

 running the cloth over a measuring drum of known circum- 

 ference, from which the yardage is registered by a dial or 

 counter driven by a chain or other positive or non-slip 

 mechanism. Just enough uniform tension" is to be used on 

 the cloth to keep it running flat and true. 



(B) WIDTH. 



5. (a) The width of a roll or piece shall be determined at five 

 different places uniformly distributed along the full length of 

 the roll or piece, and may be determined at the same time as the 

 total length. 



(fc) The average of the live measurements shall be the width. 



(C) WEIGHT. 



6. (a) Preferred Method. — The net weight of the roll or 

 piece from which covering and binding have been removed shall 

 be determined. The net weight of the roll or piece divided by 

 its superficial area in square yards shall be taken as the normal 

 net weight per square yard. 



(h) .■\LTERN.^TIVE Method. — Three samples of known area, to 

 contain not less than 4 square inches each, shall be stamped 

 (preferably cut with a steel die) from one end of the roll or 

 piece and quickly weighed. The normal square yard weight shall 

 be computed from the average weight of these three samples. 



7. (a) Preferred Method.— For the determination of dry 

 weight two test specimens of approximately equal area, each 

 not less than 4 inches in length and of the entire width of the 

 fabric, shall be cut one from each end of the roll or piece. The 

 one from the outside end of the roll shall be taken as'soon as the 

 wrapping is removed and the one from the inner end of the roll 

 as soon as the inner end of the roll has been reached in running 

 the roll. The two samples shall be taken as soon as possible. 

 These samples shall be placed in a dry air-tight container, the 

 weight of which has been previously determined, and carefully 

 weighed therein and then removed (check weight being made 

 on container), the net weight calculated and the sample dried to 

 constant weight in manner described in Section 2. The difference 

 between the original weight of sample and the dry weight is the 

 loss of moisture which when computed as percentage of the 

 dry weight is the percentage regain of the material. The dry 



•Reported for adoption, .\merican Society for Testing Materials. 



=It has been suargested that a i:iiiform tension of 2.5 times the weight of 

 five running yards of the fabric will be sufficient to keep the fabric flat 

 and preserve a proper relation fcr comparison of different fabrics. Invita- 

 tion is extended to report to the committee the results of such tests upon 

 different fabrics. 



-Method Xo 1 2 3 4 



Strip Grab Strip Single 



Method. Method. Method. Strand. 



Dimensions of specimens, in 7byl^ 5 by 2 12byl!4 



Width raveled to standard or specified 



threads per inch ] .. j 



Min. width of bottom or back jaws, in. IJ^ 2 l"^ 



Width of top or front jaws, in l<i (min.) 1 l^(min.) .. 



Distance between jaws, in 3 1 8 10 



Speed of the pulling jaw, in. per min. 20 IJ 12 12 

 Number of specimens each, waro and 



fi'lins ■ .^ .= 5 20 strand 



5.-/..y, 



Notes— 1. When material is less than 2- 

 ? cut 24 inches long and the test specime 

 anner that no part of any specimen shall 



iches wide, the swatch shall 

 shall be laid out in such a 

 le within 2 inches of either 



T-WLE II.— Tensile Strength : Test Method Ci..\ssific.'VTion. 



Name of Fabric. .No. 



Tire fabrics, including 



Carcass building fabric. 1 



Chafing strip 1 



Breaker strip 1 



Cord fabric 4 



Ducks, including 



Hos( 



Humidity Conditions, 

 f Test specimens shall be tested in a dry 

 j condition as defined in Section 2. They 

 ^ shall be taken one a» a time from the 

 drying oven and broken in the testing 

 machine within 30 seccnds from the time 

 l-of removal from the oven. 



Kelt duck 2 



Tent duck 2 



.\rmy duck 2 



Enameling duck 2 



Sail duck 2 



Numbered duck 2 



Prills 2 



5heetings 2 



Osnaburg 2 



Coutils 2 



Ballocn Cloth> 1 



s may be broken in dry 

 pecified above for tire 

 "le captioned. 



fabric^ 



(o) Speci 



"Tested Bone Dry." 



(fc) Specimens mav be tested in their 

 natural condition as taken from the roll 

 or piece and corrected for the moisture 

 present by the method of Section 12. 

 such tests to be captioned. "Corrected 

 for Standard Moisture Regain." 



Exposed before testing for at least two 

 '" ■ an atmosphei^e of 65 per cent 



degrees F. a^i 



inclination balance type 



1 relativ* humidity and 



( tested in this atmosph( 



'Balloon cloth shall be tested on machine of th 

 with ma.\imum capacity of 400 pounds. 



=The elongation of wing fabric shall be observed for each specimen when 

 subjected to loads of 10 pounds, 20 pounds and 70 pounds. Wherever possi- 

 ble autographic records shall be taken. 



Note.— Fabrics not included in the above list will be given a test method 

 classification by Committee D-13 on application of these interested. 



weight per square yard is then obtained from the normal weight 

 per square yard as obtained in Section 6 (a), as follows: 



Normal weight per sq. yd. X 100 



,„„ , : : ■ = r>ry weight per square yard. 



100 -1- percentage regain 



(b) .\ltern.\tive Method.— From one end of the roll or piece 

 five specimens, each 3 by 4.32 inches, representing 0.01 square 

 yard, shall be stamped (preferably cut with a steel die). Two 

 specimens shall be cut near the' selvages, one at the center, 

 and the other two between the selvages and the center. These 

 five specimens, with a total area equal to 0.05 square yard, shall 

 be placed in the w^re basket of a ventilated drying oven. The 



