GB443707A - Improvements in the manufacture of artificial filaments, threads, and the like - Google Patents

Abstract

<PICT:0443707/IV/1> Filaments, threads, and the like of organic derivatives of cellulose are stretched by passing them from the outer air into an end pressure chamber containing compressed air or other inert gas, in non-slipping contact with a positively driven feed device in the chamber, thence directly into a chamber containing saturated or wet steam under pressure at a temperature above 100 DEG C. and finally into the outer air, and stretching the materials whilst in the steam, the pressure of the inert gas being preferably only slightly lower than that of the steam. For example, threads 1 from a creel of bobbins 2 pass through small orifices 3 into a compressed air chamber 4, around nip rollers 5, through small orifices 6 into a steam chamber 7, through small orifices 8, and around nip rollers 9 which stretch the threads. The stretched threads are collected on another creel of bobbins 10. The chambers are each provided with a pressure gauge, relief valve, and drain pipe. The steam enters through perforated pipes 15 so positioned as to direct the steam on to the threads immediately on their entry into the steam chamber. This apparatus may also be used, as shown in Fig. 3, for stretching cellulose acetate threads in hot water as described in Specification 443,773. The threads 1 pass over nip rollers 5, enter pressure chamber 4 through an orifice 3, pass directly into the liquid treatment chamber 7 in which they are stretched, and then enter a second pressure chamber 19, finally leaving by the orifice 20. The threads pass around a second pair of nip rollers 9, which draw the threads at a higher speed than the first pair 5. Specifications 389,823, 438,584, 438,585, 438,586, 438,587, 438,655, and 438,656 also are referred to.