Significance and Use
these test methods are used to determine the stretch, growth and recovery properties that garments made with the fabric tested may be expected to exhibit during use.
these test methods is not recommended for acceptance testing of commercial shipments because the between-laboratory precision is known to be poor.
5.2.1 If there are differences of practical significance between reported test results for two or more laboratories, comparative tests should be performed by those laboratories to determine if there is a statistical bias between them, using competent statistical assistance. Use test samples that are as homogeneous as possible, are drawn from the material from which the disparate test results were obtained, and are randomly assigned in equal numbers to each laboratory for testing. The test results from the two laboratories should be compared using a statistical test for unpaired data, at a probability level chosen prior to the testing series. If a bias is found, either its cause must be found and corrected, or future test results for that material must be adjusted in consideration of the known bias.
Some stretch fabrics are constructed with stretch yarns in only the filling direction. Consequently, for those fabrics, only the filling direction needs to be tested.
1.1 These test methods cover the determination of the amount of fabric stretch, fabric growth, and fabric recovery of fabrics woven in whole or in part from stretch yarns after a specified tension and extension.
1.2 These test methods are intended for use with woven fabrics exhibiting high stretch (greater than 12 percent) and good recovery properties from low tension (up to 360 g/cm or 2 lb/in. of fabric width). When agreed upon, these test methods can be used for fabrics woven in whole or in part from non-stretch yarns that exhibit limits within the stretch characteristics shown above.
1.3 These test methods allow the use of two tension options commonly used in the textile industry; 1.35 kg (3 lb.) and 1.8 kg (4 lb). Several calculations are included for fabric stretch, fabric growth and fabric recovery, and can be used individually when required by individual specifications.
1.4 These test methods should not be used to measure breaking elongation of woven fabrics which is covered in Test Method D 5035.
1.5 The values stated in either SI units or inch-pound units are to be regarded separately as the standard. Within the text, the inch-pound units are shown in parentheses. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the specification.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.