纺织品.纱线捻度的测定. 直接计数法(ISO 2061:2015)

[中文适用范围]： 本标准规定了用直接计数法测定退捻纱线和加捻纱线时捻向、单位长度捻数和长度变化的方法。 本国际标准适用于 a) 单纱（短纤纱和长丝纱），b) 单股多捻纱，c) 多股捻纱。 针对上述每种类型的纱线或麻线给出了单独的方法。 该工艺主要针对展示单元中的纱线和线而设计，但在采取特殊预防措施的情况下，该工艺也可用于从机织物和针织物中提取的纱线和线。 它不适用于测定单丝的捻度。 注：另见 ISO 1890（专门为满足玻璃纤维技术的需要而制定）和 ISO 7211-4。 本标准适用于单步捻度和多步捻度捻度的测定。 a) 对于单段倍捻：单段倍捻的终捻和各单纱加捻前的初捻。 b) 对于多级捻：多级捻的最终捻度；加捻后、最终加工阶段前的单段倍捻的初捻度；加捻前各单纱的捻度。 如果需要，可使用 10.5.7 的特殊方法来确定单纱的捻度和单道多捻纱的成分，因为它们存在于最终结构中。 除非另有约定，本国际标准不适用于当每单位纱支纱线张力从 0.5 cN/tex 增加到 1.0 cN/tex 时伸长超过 0.5% 的纱线。 如果对测试结果感兴趣的所有各方都接受，则可以在特殊的纱线张力条件下对此类纱线进行测试。 本国际标准不适用于气流纺纱和混纺复丝纱。 本国际标准不适用于太粗而无法插入测试仪钳口而不断裂或严重损坏的纱线，这可能会影响测试结果。 [外文原描述]： ISO 2061:2015 specifies a method for the determination of the direction of twist in yarns, the amount of twist, in terms of turns per unit length, and the change in length on untwisting, by the direct counting method. This International Standard is applicable to a) single yarns (spun and filament), b) plied yarns, and c) cabled yarns. Separate procedures are given for each type of yarn. The method is designed primarily for yarns in packages, but, with special precautions, the procedures can be used for yarns taken from fabrics. It is not suitable for the determination of twist in a monofilament. NOTE See also ISO 1890, which was prepared especially for the needs of glass textile technology, and ISO 7211‑4. ISO 2061:2015 covers the determination of twist in plied and cabled yarns as follows: a) in plied yarns: the final twist of the plied yarns and the original twist of the single yarn before plying; b) in cabled yarns: ? the final cabling twist of the yarn; ? the original twist of the plied yarn after plying, but prior to the last stage of processing; ? the twist of the single yarn before plying. If desired, the twist of single and plied yarn components, as they lie in the final structure, can be determined by the special procedure given in 10.5.7. ISO 2061:2015 is not applicable, except by agreement, to yarns which stretch more than 0,5 % when the tension increases from 0,5 cN to 1,0 cN per unit linear density of the yarn expressed in tex. Such yarns can be tested under special conditions of tension which are accepted by all parties interested in the test results. ISO 2061:2015 is not suitable for products of open-end spinning and intermingled (interlaced) multifilament yarns. ISO 2061:2015 is not applicable to yarns which are too large to permit their being placed in the clamps of the testing apparatus without crushing or distortion severe enough to affect the test results.