GB398738A - Improvements relating to the manufacture of artificial silk - Google Patents

Abstract

Artificial silk which has been washed free from acid and dried is twisted and wound on to a bobbin of variable diameter, and the wound package of threads, after diminishing the diameter of the bobbin, is irrigated with the after-treatment liquids. The bobbin is preferably made of elastic material and slit along its longitudinal axis. The bobbin is expanded by introducing a core of somewhat greater diameter than the normal internal diameter of the bobbin. The core may be formed of two parts one of which is introduced into each end of the bobbin thus causing the slit to be widened. The centre of each part of the core carries a pin adapted to rotate in a slot in the twisting machine. The bobbin may be driven by a rotating shaft against which the bobbin presses by its own weight. Parts of the core which extend into the bobbin may be conical. The bobbin may be of aluminium, or other metal coated with lacquer, or of an artificial material reinforced by embedded metal rings or cloth. The bobbin may be of much larger diameter than is usual. The core may be of wood, metal or an artificial substance. The after-treatment and drying may be effected with the lap still on the bobbin of reduced circumference or after removal. To protect the threads, a permeable or non-permeable textile, felt, rubber, or other covering may be placed over the bobbin before winding on the thread. If the covering is permeable, it may be employed to protect the threads during the subsequent wet treatments and the ends may be drawn over the wound lap. It <PICT:0398738/IV/1> <PICT:0398738/IV/2> <PICT:0398738/IV/3> <PICT:0398738/IV/4> may serve to prevent the lap from being soile by solid impurities in the liquids used. As shown in Fig. 3, an expansible bobbin 1 is expanded by means of core members 3 with pins 4 which rotate in slots in the twisting machine. As shown in Fig. 5, a covering of tricot-cloth 7 has been placed over the surface of the bobbin 1 before winding on the threads to form the lap 6. The core member 3 maintains the slit 2 in its open position and keeps the bobbin expanded. As shown in Fig. 6, the cores have been removed and the bobbin has resumed its reduced diameter as shown by the slit 2. The fabric 7 is wrapped round the thread lap 6. As shown in Fig. 7, a number of bobbins 1 with their thread laps 6 are placed on rods 9 and sprayed with liquids. The threads may subsequently be wound on to cops or spools.