【国外标准】 Standard Test Methods for Sewing Threads

4.1 Acceptance Testing—The test methods in Test Methods D204 for the determination of the properties of sewing thread are considered satisfactory for acceptance testing of commercial shipments of sewing thread, unless specified in the individual test method. These test methods are the best available and are used extensively in the trade.4.1.1 If there are differences of practical significance between reported test results for two laboratories (or more) comparative test should be performed to determine if there is a statistical bias between them using competent statistical assistance. As a minimum, use the samples for such a comparative tests that are as homogeneous as possible, drawn from the same lot of material as the samples that resulted in disparate results during initial testing and randomly assigned in equal numbers to each laboratory. The test results from the laboratories involved should be compared using a statistical test for unpaired data, 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.1.1 These test methods can be used to evaluate sewing threads of any fiber.1.1.1 The test methods in this standard are intended to evaluate only sewing thread taken from thread holders.1.2 These test methods only provide for the measurement of sewing thread physical properties. These test methods do not address any other properties that may be important for the satisfactory performance of sewing threads under particular end use conditions.1.3 These test methods can be used to measure the following properties:  SectionsColorfastness to Drycleaning 73 – 83Colorfastness to Laundering 62 – 72Colorfastness to Water Migration 84 – 94Diameter 43 – 50Length per Thread Holder 34 – 42Shrinkage, Single Strand 51 – 61 Dry Heat 58.1 Boiling Water 58.2Strength and Elongation 15 – 21 Single Strand—Conditioned 19.1.1 Single Strand—Wet 19.1.2 Loop Strength 19.2 Knot Strength 19.3Twist 22 – 27Twist Balance 28 – 33Yarn Number 7 – 14NOTE 1: For methods covering tests on prepared seams, refer to Test Methods D1683/D1683M and D3940.1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.