GB/T 7690.3-2001 in English

《GB/T 7690.3-2001增强材料 纱线试验方法 第3部分:玻璃纤维断裂强力和断裂伸长的测定》由TC245（全国玻璃纤维标准化技术委员会）归口，主管部门为中国建筑材料联合会。
本标准规定了以卷装形式提供的玻璃纤维纱线断裂强力和断裂伸长的测定方法。本标准适用于各种]类型的玻璃纤维纱（单纱、合股纱、缆纱、原丝、绝对无捻粗纱、无捻粗纱等）。适用于从卷装所取的直径小于2mm或线密度小于2000tex的玻璃纤维单纱、合股纱和缆纱。如果提供的测试条件能够为关心测试结果的各方接受，也可以用于直径大于2mm或线密度大于2000tex的纱线的测定。本方法不适用于经标准环境调湿和施加5mN/tex预张力条件下伸长率超过0.5%的玻璃纤维纱。这种纱可在有关各方同意的条件下，采用较低的预张力（如2.5mN/tex或1mN/tex）进行测试。这种情况主要出现在定长纤维纱。

Scope

1.1 This standard specifies the method for measuring the breaking strength and breaking elongation of glass fiber yarn provided in package form. 1.2 This standard is applicable to various types of glass fiber yarns (single yarn, ply yarn, cable, raw silk, absolute roving, roving, etc.). Suitable for glass fiber single yarn, plied yarn and cable with diameter less than 2mm or linear density less than 2000tex taken from the package. If the measurement conditions provided can be accepted by all parties concerned about the test results, it can also be used for the measurement of yarns with a diameter greater than 2mm or a linear density greater than 2000tex. 1.3 This method is not applicable to glass fiber yarns whose elongation exceeds 0.5% under the conditions of standard environmental humidity adjustment and 5mN/tex pretension. Such yarns may be tested with a lower pretension (such as 2.5mN/tex or 1mN/tex) under the conditions agreed by the parties concerned. This situation mainly occurs in staple fiber yarns. Note: 1. This method can also be used to determine beam yarn or yarn taken from fabric, but the test result is only for status indication. 2. This method is mainly used for the determination of material properties and quality control. Fiber-to-fiber friction and factors such as uneven tension (drapability) will increase the dispersion of test results, resulting in low test values. This necessarily affects the exact correlation between yarn properties and final application results. 3. Although this standard provides the possibility to determine the elongation at break, this method is not recommended. Indeed, the correct way to measure elongation at break is only with an extensometer and not based on the displacement of a moving fixture beam. But on the other hand, experiments have shown that the use of extensometers to measure is very accurate, but it is easy to damage the sample.