GB347878A - Improvements relating to the manufacture of artificial threads - Google Patents

Abstract

<PICT:0347878/IV/1> <PICT:0347878/IV/2> <PICT:0347878/IV/3> <PICT:0347878/IV/4> Artificial threads are made by a stretch-spinning process wherein the threads pass in a substantially vertical direction through a vessel supplied with liquid which causes preliminary coagulation, and subsequently in a substantially vertical direction through at least one other vessel supplied with a coagulating liquid different from that supplied to the first vessel, and so arranged with respect to the outlet of the first vessel that liquid flowing through this outlet does not enter the further vessel. In the production of cuprammonium silk, for instance, the first liquid may be alkaline, and the second liquid acid in reaction, and it is therefore necessary to avoid intermingling. The coagulated thread may also travel vertically through one or more vessels through which washing liquid flows. The vertical direction of the threads leads to considerable saving of space especially if the several treatment vessels are placed one above another. The axis of the draft roller may be placed normal to a row of spinning vessels. As shown, a conical spinning funnel 1 has a curved discharge nozzle 2 and a liquid inlet 3. The thread passes through the spinning funnel in vertical direction and then enters a similar vessel 4 which is fed with acid, and travels vertically through this vessel. It is then passed round a draft roller 6 and collected in a spinning box 7. In a modification, the discharge nozzles of the spinning funnel and of the subsequent vessels are axially placed, and in order to avoid intermingling of the liquid in the upper vessel with that of the lower vessel, these vessels are displaced laterally from each other. Between the spinning funnel and the acid vessel and between the acid vessel and a washing vessel, the thread may be passed over adjustable brakes by means of which the tension may be increased or diminished. In Fig. 4, the coagulation vessels 1, 4 are arranged vertically one below the other and the thread is guided by means of rollers 13 around the tanks 14 which collect the liquids issuing from the vessels. In another arrangement, the vessels 1, 4 are placed side by side, the thread passing downwards through the spinning funnel, round a roller, and then upwardly through the vessel 4 in which the liquid flows in the opposite direction to that of the thread. In order to facilitate entry of the thread issuing from the spinning vessel into the further vessel, the upper part of the latter may be constructed as shown in Fig. 5. The coagulating liquid enters at 3 into an annular-shaped chamber 15 within the funnel, and flows from this chamber through an annular slit 16, passing down the inside face of the funnel. The thread is thus prevented from sticking to the sides of the funnel. The side of the coagulation funnel 4 may be slotted as shown in Fig. 7 at 17, and provided with a sleeve 18 similarly slotted and also connected to the liquid inlet. When the two slots are in register, the supply of liquid is cut off and the thread may be introduced into the funnel. The parts 4, 18 may then be rotated relatively to each other until the slot 17 registers with the liquid inlet.