GB396792A - Improvements in or relating to the manufacture of artificial filaments and the like - Google Patents

Abstract

<PICT:0396792/IV/1> <PICT:0396792/IV/2> <PICT:0396792/IV/3> <PICT:0396792/IV/4> In the dry spinning of artificial filaments two or more than two streams of air &c. are directed against the filaments, in the neighbourhood of their point of extrusion, from different sides at different distances from the spinning nozzle, for example, in the case of two such supplies at points two and four inches respectively from the nozzle. The air jets may be sufficiently wide to include all the filaments proceeding from the nozzle, for example, they may be of the fish-tail gas burner pattern, so as to project a wide flat stream, or they may be arranged tangential to the bundle of filaments; and they may be directly transverse to the line of travel of the filaments or may be inclined in an upward or downward direction thereto. The currents of air which are preferably of high velocity, may be created by supplying air under pressure from the outside, or by suction, or by convection while utilizing the heating system of the spinning cells. The air supplied by the jets may be cold, or it may be heated as by passing the supply pipes through the cells. To enable access to be gained to the spinning nozzle, the air jets may be removable, or they may be capable of being moved to an inoperative position as by the act of opening the spinning cell door, and the arrangement may be such that movement of the air jet automatically cuts off the air supply. The supplied air may contain other gases or vapours such as the vapour of the solvent contained in the spinning solution. The devices may be used alike in apparatus for upward or downward spinning and having a counterflow of evaporative medium or a flow in the same direction as the filaments. In the form shown in Fig. 1 the air adjacent to the sets of heating pipes 25 at the back and front of the spinning cell is isolated by plates 27 to form chambers terminating in nozzles 28, 29 directed towards the filaments 14 at different levels; the nozzles and plates are hooked on to the heating pipes, an arrangement which facilitates access to the spinning nozzle 13 so that the nozzle 29 nearer to the door 33 may be lowered into the cell the other nozzle 28 being at the same time protected by a cap. In the form shown in Figs. 4 and 5, additional air is supplied under high pressure through three jets 47, 48, 49 situated at different levels and directed in a tangential manner to the filaments 14; the jets 48, 49 are carried by swivel pipes, and the requisite amount of air is supplied to the jets by means of interchangeable screwed plugs 56, Fig. 6, having apertures 57 of appropriate size, access to the plug being had by means of a screwed cover 59, Figs. 4 and 6. Specifications 325,233, [Class 2 (ii), Cellulose &c.], 392,218 and 397,114 are referred to.