Influence of Frictional Characteristics of Core and Sheath on Twist Structure and Tensile Properties of DREF-3 Friction Spun Yarns Part Ⅰ: Filament-core DREF-3 Friction Spun Yarns

摘要

The influence of fibre friction on twist structure and tensile properties of filament-core DREF-3 friction spun yarns has been investigated. A 110/48 dtex polyester multi-filament in three different forms - namely, flat, twisted, and textured - was used for the core, and acrylic fibres of 38 mm and 1.65 dtex with three different add-on levels of polyethylene glycol 400 (PEG) finish were used for the sheath, to spin a set of nine yarns, each of 37 tex with a core: sheath ratio of 30:70. It was found that an increase in fibre-to-filament and fibre-to-fibre friction to a certain extent improves the twisting/wrapping of sheath fibres over the core in the yarn. The increased sheath fibre twist reinforces the yarn structure, resulting in increased yarn strength and enhanced sheath slipping resistance over the filament-core. The filament-core was found to exhibit twist in both Z and S directions. The sheath fibres were observed to be arranged in layers and to exhibit differential twist structure.