GB579064A - Improvements in or relating to the manufacture of wet-spun artificial threads or yarns - Google Patents

Abstract

<PICT:0579064/IV/1> Wet spun artificial threads or yarns produced, for example, from viscose, are subjected to a continuous after-treating process wherein the freshly spun threads collected in package form are mounted, unwound at a rate of approximately 300 metres per minute and subjected during their travel over a plurality of thread-storage, thread-advancing devices to treatment with washing and finishing liquids and to drying, before being finally collected at a rate of approximately 300 metres per minute. As shown in Fig. 1, freshly spun viscose thread 4 is unwound from package 3, washed on rollers 5, desulphurized on rollers 6, washed on rollers 7, finished on rollers 8, dried, under tension if desired, on heated rollers 10 and wound up at high speed by suitable traversing mechanism in the form of a conical package 13. The thread may be subjected to oiling or other treatment normally incident to cone winding in its passage between rollers 10 and the traversing mechanism. The thread may be subjected to other treatments such as bleaching in the continuous operation, and adjacent pairs of treatment rollers may be driven at successively greater or lower speeds in order to stretch or relieve the tension on the thread. The pairs of rollers 5, 6, 7, 8 and 10, one or both of which are driven, have their axes offset in order to advance the thread thereover in a helical path. The coning spindle speed may be gradually decreased as the thread builds up on package 13. In order to effect continuity, two adjacent cakes of freshly spun yarn may have their ends tied together so that when one cake is completely unwound, thread is withdrawn from the second cake. The thread may be twisted by replacing the coning mechanism by a ring or cap twisting mechanism, the coning operation then being effected separately and subsequently. If desired, the drying rollers and coning mechanism may be mounted in sequence above the finishing rollers 8 or alternatively the entire treating and coning operation may be effected with the thread moving downwardly. The freshly spun thread may be produced by the two-bath process, wherein the thread is highly stretched in a heated bath prior to collection in a centrifugal pot or on a bobbin.