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Significance and Use
6.1 This method is considered satisfactory for acceptance grading of commercial shipments because it has been used extensively in the trade for this purpose.
6.1.1 If there are differences of practical significance between reported test results for two laboratories (or more), comparative tests 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.
6.2 The appearance of a woven or knitted fabric depends to a large extent on the smoothness, cleanliness, and general appearance of the yarns from which the fabric is manufactured. Instruments are available for the measurement of unevenness and for counting neps and other imperfections in yarn, but the values obtained from such tests are not easily integrated into an over-all expression for actual fabric appearance. Yarn appearance grading affords additional information which the manufacturer of woven or knitted goods may, through experience, correlate with the appearance to be expected in fabrics made from the yarns.
1.1 This test method covers the grading of singles spun yarns for appearance.
1.2 This test method does not apply to plied yarns.
1.3 The values stated in either inch-pound or SI units are to be regarded separately as the standard. The values stated in each system are not exact equivalents, therefore, each system must be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.4 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.
1.5 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.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D123 Terminology Relating to Textiles
D2258 Practice for Sampling Yarn for Testing
D2645 Tolerances for Yarns Spun on the Cotton or Worsted Systems
D3888 Terminology for Yarn Spinning Systems
D3990 Terminology Relating to Fabric Defects
D4849 Terminology Related to Yarns and Fibers
ICS Number Code 59.080.20 (Yarns)
UNSPSC Code 11151700(Yarns)
|Link to Active (This link will always route to the current Active version of the standard.)|
ASTM D2255 / D2255M-09(2020), Standard Test Method for Grading Spun Yarns for Appearance, ASTM International, West Conshohocken, PA, 2020, www.astm.orgBack to Top