GB1133899A - Process and device for mercerising cotton yarn - Google Patents

Abstract

1,133,899. Mercerising cotton yarn; textile treating apparatus. VEPA A.G. 1 March, 1967 [1 April, 1966], No. 9682/67. Headings D1L and DIP. Cotton yarn is mercerised by continuously moving a continuous hank of the yarn through a series of locations in which it is first contacted with hot and/or cold water impregnated under tension with caustic soda at a temperature below 20‹C and then washed, steamed, neutralised and dried, the hank being squeezed at least after each wet-treatment. The yarn may be rinsed after steaming and may be finished with oily or oil containing agents prior to drying. Before finishing and/or drying the yarn may be bleached, e.g. with hydrogen peroxide, steamed and rinsed. In Fig. 1 several hanks of yarn 1 are wetted and washed in two sieve drum baths 2 each comprising a trough 3 which is filled with liquor, a sieve drum 4 subjected to suction by means of pump 7, guide roller 5 and squeeze rollers 6, optionally fitted with a heating unit, the liquid being discharged through duct 8 and returned into the bath. The yarns are then impregnated with caustic soda in bath 9 which is generally provided with a cooling device so that the caustic soda is kept at a temperature below 20‹C and in which is arranged a lower row of rollers 10 for guiding the yarn and above which is a row of rollers 10' each correlated with a squeeze roller 11, and are reimpregnated in a further bath 12. The yarns are then washed in sieve drum wash baths 13 and 14, steamed in steamer 15 comprising sieve drums 16 subjected to suction, rinsed, acidified and/or neutralised and finished in sieve drum baths 17, 18 and 19 and dried on sieve drum dryer 20 comprising sieve drums 21 subjected to suction. The sieve drum bath 13 may be replaced by a washing bath of a similar design to baths 9 and 12 and the steamer 15 may be replaced by a J-box in which the hanks of yarn are arranged in folds in the steam atmosphere. If the yarn is also to be bleached at least one bath with bleaching liquor and a sieve drum subjected to suction, a steaming chamber which may be a J-box, and at least one wash bath with a sieve drum subjected to suction may be provided in front of the finishing bath or dryer. To prevent tension on the yarn during drying the dryer intake may be sealed by means of a pair of rollers made of soft rubber driven at a higher speed than the subsequent sieve drum, one intake roller preferably the upper roller, being forced hydraulically against the other one. To eliminate the necessity of synchronizing the speeds of the individual units according to the respective material shrinkage values a material store may be provided at least behind one individual unit or compensating rollers may be provided.