ASTM D3822/D3822M-14

5.1 Test Method D3822 using test specimens having gauge lengths of 10 mm [0.4 in.] or greater is considered satisfactory for acceptance testing of commercial shipments since the test method has been used extensively in the trade for acceptance testing. Critical differences noted in 5.1.1 In cases of a dispute arising from differences in reported test results when using Test Method D3822 for acceptance testing of commercial shipments, the purchaser and the supplier should conduct comparative tests to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended for the investigation of bias. As a minimum, the two parties should take a group of test specimens which are as homogeneous as possible and which are from a lot of material of the type in question. The test specimens should then be randomly assigned in equal numbers to each laboratory for testing. The average results from the two laboratories should be compared using Student's t-test for unpaired data and an acceptable probability level chosen by the two parties before the testing begins. If a bias is found, either its cause must be found and corrected or the purchaser and the supplier must agree to interpret future test results for that material in view of test results with consideration to the known bias.

5.2 The breaking tenacity, calculated from the breaking force and the linear density, and the elongation are fundamental properties that are widely used to establish limitations on fiber processing or conversion and on their end-use applications. Initial modulus is a measure of the resistance of the fiber to extension at forces below the yield point. The tangent modulus and tensile stress at specified elongation may be used to differentiate between the probable performance of fibers in processing and end-use performance. The breaking toughness is an indication of the durability of materials produced from the fiber.

5.3 It is recognized that computerized results are used extensively in the industry. When comparing results from two laboratories using computerized tensile testers, the algorithms used to derive results must be examined for parity, that is, how the maximum slope and specimen failure or rupture are determined.

5.4 The breaking strength of wet fibers tested in air may be different from wet fibers tested while immersed.

1.1 This test method covers the measurement of tensile properties of natural and man-made single textile fibers of sufficient length to permit mounting test specimens in a tensile testing machine.

1.2 This test method is also applicable to continuous (filament) and discontinuous (staple) fibers or filaments taken from yarns or tow. When the fibers to be tested contain crimp, or if the tow or yarns have been subjected to bulking, crimping, or texturing process, the tensile properties are determined after removal of the crimp.