GB846520A - Apparatus for wet spinning and stretching artificial filamentary materials, particularly viscose rayon - Google Patents

Abstract

<PICT:0846520/IV(a)/1> In apparatus for the production of artificial threads, particularly viscose rayon, by wetspinning of the kind in which the filaments, after leaving the coagulating bath, are continuously stretched by passing them in succession over two sets of rotating rollers, the second set having a higher peripheral speed than the first, and in which the filaments, during their passage from the first set of rollers to the second, pass through a bath of hot liquid, said bath is contained in a longitudinal horizontal closed cell having an inlet for the supply of liquid, an orifice at each end for the discharge of the liquid and the passage of the filaments and also at each end, a chamber into which the orifice at the end of the cell leads, which chamber is also provided in its opposite wall with an orifice for the passage of the filaments and, in its bottom wall, with an outlet for the discharge of the liquid which continuously flows into the chamber from the cell. In the example, a bundle of filaments of regenerated cellulose, produced by the extrusion of viscose into a conventional coagulating bath, is withdrawn from the bath by a pair of co-acting rolls whose axes are horizontal and is drawn through a longitudinal horizontal closed cell 10 having an approximately elliptical cross-section and an internal height over four times its internal width. The cell is provided with end chambers 11, 111 having nozzles 12, 121 aligned with the inlet and outlet holes 13, 131 for the filaments. A liquid such as water at 95 DEG C. is introduced into the cell through the inlet 14 and is discharged from the chambers 11, 111 through the outlets 15, 151. Gases and vapours such as carbon bisulphide escape from the cell 10 through the outlet 16 in the top of the cell which slopes upwards to this outlet to prevent the trapping of any gases in the cell while spinning is in progress. The chambers 11, 111 remain filled with bath liquid and thus prevent the building up of deposits of salts at the apertures 13, 131, damage to the filaments during their passage through the apertures thus being prevented. The bundle of filaments travels from the outlet 131 of the stretching cell to a draw roll, the axis of which is vertical.