Abstract: Yarn hairiness is one of important yarn parameters, which is used for yarn production quality control. It is usually characterized by the amount of free fibers (fibre loops, fibre ends) protruding from the compact yarn body towards the outer yarn surface. The first question can be if hairiness is really important and why? The reason is obtaining deeper information about yarn structure and its changes during processing. Thanks to detailed knowledge it is possible predict to yarn behaviour and design fabric and textile products precisely in the way the customers demand. Yarn hairiness and its determining is important because it influences the post spinning operation and parameters of textile product (porosity, permeability, transport of moisture, comfort, aesthetic properties and hand). The main factors influencing hairiness are: type of fibres, yarn twist, yarn count, blending ratio, yarn technology production, approach to yarn hairiness observation and measurement condition. This paper concentrates on the influence of yarn construction parameter (yarn count, yarn twist) and technology of production (ring comb and carded, experimental and open end). In this case, the Uster Tester 4 and the new optical approach for yarn hairiness investigation is applied. Results for experimental sets of yarn will be shown.

Key words: Yarn hairiness, yarn diameter, yarn count, yarn twist