GB787561A - Improvements in the manufacture of artificial filamentary material - Google Patents

Abstract

<PICT:0787561/IV (a)/1> In wet-spinning wherein the filaments are drawn through and out of a narrow tube through which coagulating liquid flows, the filaments are drawn by a godet comprising a number of equally spaced parallel or nearly parallel thread-carrying bars. The bars are preferably cylindrical and are preferably supported at one end only, the other ends being left free or merely held by a spacing member. As shown, filaments from the jet 5 are spun into coagulating liquid in extrusion chamber 4 and are drawn up the setting tube 10, also containing coagulating liquid, by godet 17 which comprises a number of cylindrical rods 20 carried at one end by a driven disc 18, which imparts stretch. Excess coagulating liquid is removed from the filaments by a pigtail guide 16 and inverted funnel 15 as described in Specification 787,556. The filaments then pass to washing device 21 comprising a pair of skew rollers 22 partly immersed in water, then over godet 26 to further washing baths or to a takeup device. The further washing may be effected in an apparatus (Fig. 3, not shown), wherein the filaments are passed several times round a pair of rollers of which the lower roller is driven, cylindrical and is immersed in the washing liquid, and the upper is freely mounted and is either made up of a number of parallel bars or is a fluted roller, as described in Specification 787,558, or has any other shaped periphery which makes contact with the filaments at intervals along their length. The invention is of particular value in the manufacture of cellulose acetate by extruding an acetone solution of cellulose acetate into an aqueous solution of diethylene glycol diacetate or of acetone, but it may be used in other wet-spinning processes, e.g. in the spinning of acetic acid solutions of cellulose acetate into aqueous acetic acid containing a high concentration of a salt such as an alkali metal acetate.