GB679547A - Improvements in or relating to the manufacture of regenerated cellulose rayon yarn - Google Patents

Abstract

Regenerated cellulose continuous filaments are stretched beyond their yield point whilst in a normally dry state, their moisture content is then increased and finally a portion of said moisture is removed, as by drying. Filaments in the normally dry state are defined as filaments possessing an equilibrium moisture content under normal atmospheric conditions, i.e. having a moisture content of less than about 15 per cent by weight. The stretched filaments may be formed into a package prior to wetting. Preferably, the filaments are stretched beyond their breaking point to produce staple fibre, which is wetted, dried and may be subsequently spun into yarn. The Specification as open to inspection under Sect. 91 comprises also a modification of the process in which the filaments, having been drafted and broken into staple fibre, are spun into a yarn which is then wetted and dried. In an example, an untwisted bundle of viscose filament rayon of 2200 denier, dry strength 2.9 g./denier and 6 per cent stretch is drawn into 9-inch staple fibre between two sets of rollers. The sliver so formed is immediately wound and twisted on a bobbin by a ring spinner into a yarn having a cotton count of 30/1, a strength of 2.5 g./denier and an elongation of 5.6 per cent. The bobbin is immersed in water at room temperature for an hour and then dried in an oven. The final yarn has a count of 30/3, strength 2.65 g./denier and an elongation of approximately 10.6 per cent. This subject-matter does not appear in the Specification as accepted.