Establishment of quantification methods for novel polypropylene/polyamide 6-based bicomponent fibre in textile binary mixtures

The aim of this study was the establishment of quantification methods for binary mixtures containing a novel polypropylene/polyamide 6-based bicomponent fibre, for which a new generic fibre name has been requested to the European Commission. Application of such methods is requested by EU legislation to enable market surveillance of the compulsorycomposition labelling of textile products. Evaluating the key parameters for quantification, results showed that the b coefficient for the novel fibre (mass loss due to normal pre-treatment) is equal to 0%. In agreement with the members of the European Network of National Experts on Textile Labelling, the value of 1.00% was established as its agreed allowance (moisture regain in standard atmosphere), on the basis of the experimental value of 0.54%. Among the dissolution methods described in Directive 96/73/EC, the new fibre was insoluble in ten, for which the d correction factors (mass loss of the insoluble component) were evaluated. Three of them were additionally validated through an EU collaborative trial according to ISO 5725:1994. The ten established d correction factors were in the range of 1.00–1.01, revealing complete insolubility or up to 1% solubility of the novel fibre in the dissolution reagents. Based on this study, laboratories now have at their disposal methods to quantify the new fibre in binary mixtures with polyester, elastomultiester, polyamide, chlorofibres, certain acrylic and modacrylic fibres, acetate, triacetate, polylactide, certain cellulose fibres and certain protein fibres.