纤维混纺产品定量方法中甲酸/氯化锌法的局限性

棉与粘纤、莱赛尔、莫代尔等再生纤维素纤维混纺产品定量方法主要采用甲酸/氯化锌法,但实际检测中发现该法测试结果不稳定,为此,从染料是否去除、粘纤含量高低、棉纤维损伤程度三方面进行多组试验。结果表明:采用活性染料染色的棉与再生纤维素纤维混纺产品,尤其棉/莱赛尔混纺产品,剥色处理会降低染料对测试的影响,且剥色对样品没有损伤;粘纤含量的过高或过低对测试结果稳定性的影响较大,尤其粘纤含量小于5%或大于95%时;对于已发生化学降解的棉纤维的混纺产品,甲酸/氯化锌对其损伤程度加剧,测试结果可信度低。因此,再生纤维素含量过高或过低时、不能完全溶解或者过分溶解的棉与再生纤维素纤维混纺产品,建议采用FZ/T 01101—2008《纺织品纤维含量的测定物理法》标准中的显微镜物理测定法进行试验。

Limitation of Formic Acid/Zinc Chloride Method among Quantitative Methods of Fiber Blended Products

The quantification of regenerated cellulose fiber blended products such as cotton and viscose,leisel and modal mainly uses formic acid/zinc chloride method.However,it is found in practical test that this method has an unstable test result.Therefore,this paper conducts multiple tests from three aspects-dye removal,viscose content and damage degree of cotton fiber.The result shows that,for cotton and regenerated cellulose fiber blended products dyed with reactive dyes,especially cotton/leisel blended products,stripping processing will reduce the influence of dyes on the test and will not damage the sample.Inappropriate viscose content has great influence on the stability of test result,especially when viscose content is less than 5% or more than 95%.For blended products of cotton fiber with chemical degradation,formic acid/zinc chloride will damage them more deeply and the test result has a low reliability.Therefore,for cotton and regenerated cellulose fiber blended products with inappropriate regenerated cellulose content or regenerated cellulose that cannot dissolve or that dissolves excessively,it is suggested to conduct a test with microscope physical measurement method in FZ/T 01101—2008Textiles-Measurement of Fiber Content-Physical Method.