ASTM D 1423 : 1999

1.1 This test method covers the determination of the amount and direction of twist at the completion of any stage of twisting in single (spun or filament), plied, cabled, or novelty (exclusive of long-term repeat patterns) yarns. The procedures are designed primarily for yarns in packages, but, with special precautions, they are applicable to yarns taken from fabrics. The procedure for spun yarn in 9.2 is also applicable to rovings. For tire yarns/cords and industrial yarns/cords use conditions as specified in Methods D885 and D885M.

1.2 For plied yarns, this test method covers the determination of the twist of the plied yarns and the twist of the single yarn before plying. For cabled yarns, the test method covers the determination of the cable or hawser twist; the twist of the plied yarn after plying, but prior to the last twisting operation; and the twist of the single yarn before plying. Procedures are also included for the determination of the twists of the single and plied yarn components as they lie in the final structure.

1.3 This test method is not intended for yarns that extend more than 5.0% when tension is increased from 2.5 to 7.5 mN/tex (0.25 to 0.75 gf/tex). However, the method may be applied to such yarns when mutually agreed upon tensions are used.

1.4 This test method is being evaluated for use in determining twist in open-end yarns using short lengths.

1.5 This standard does not purport to address all of the safety problems, 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. >