Patent GB-391782-A (GB)
Title: Improvements in the treatment of artificial fibrous materials
IPC: F16L41/02
Filed: 1931-11-02
Abstract: <PICT:0391782/IV/1> <PICT:0391782/IV/2> <PICT:0391782/IV/3> Artificial filaments, threads, yarns, and the like are treated with a softening agent and subjected to a stretching operation, application of the softening agent or of the stretching tension or both being at least partially effected by means of one or more freely mounted rollers.  When the rollers serve to apply the stretch they are provided with means to restrict their free rotation.  They may be constructed of aluminium or other light metal, or of phenolaldehyde resin.  They may be provided with grooves to guide the filaments. For applying the softening agent the filaments may be passed over the freely mounted rollers which dip into vessels containing the softening agent.  If desired, the filaments may pass under the freely mounted rollers which are lowered so as to dip with their outer peripheries in the softening liquid.  The filaments which are situated in the grooves of the rollers are not in direct contact with the bath of softening liquid.  Rotation of the freely mounted rollers may be opposed and controlled by adjusting the weight of the rollers, or by causing them to run in contact with a viscous liquid, or they may carry vanes which are exposed to the fluid drag of a gaseous or liquid medium.  A jet of air or other gas may be directed upon the vanes to oppose rotation or the vanes may be disposed in a closed compartment.  Electromagnetic devices may be employed for retarding rotation of the rollers.  The softening agent may be acetic acid, formic acid, lactic acid, diacetone alcohol, acetone, ethers, esters and ether-esters of olefine and polyolefine glycols, dioxane, mono-ethyl ether of diethylene glycol, glycol acetates, methyl glycol acetate, acetins, phenols, dichlorethylene, methylene chloride, ethylene chloride, methyl acetate, or ethyl acetate The softening agent may be diluted with water, alcohols, ethers, or hydrocarbons. The stretching may be restricted to the softened portion of the thread.  After stretching, the softening agent may be removed by drying or washing, preferably in solutions of softening agent of increasing dilution.  The filaments, subsequently to the streching, may be subjected to a shrinking treatment.  The process is applicable to filaments of cellulose acetate or other organic ester of cellulose, or of cellulose nitrate, or of ethyl, benzyl or other ether of cellulose, or of mixed esters, ethers, or ether-esters of cellulose, or to cellulose filaments produced by the viscose, cuprammonium, or nitro-cellulose processes.  The swelling agent for cellulose filaments may be Schweitzer's reagent, caustic alkali, or a thiocyanate.  As shown in the drawings, a freely mounted roller 1 has a groove 2 and is placed so that only the outer periphery is immersed in the bath of softening agent 3.  The roller is provided with vanes 4 partially immersed in the liquid. Shields 5 prevent turbulence in the liquid near the roller.  The vanes 4 may be pivotally mounted on the roller shaft so that they may be disposed at any desired angle to the axis.  As shown in Fig. 3, the filaments 13 are led from a bobbin or other package to a feed roller 9 and thence over a freely mounted roller 10 dipping in softening liquid 11.  A roller 12 rotating at a greater peripheral speed than roller 9 stretches the filaments which are then washed, wound and twisted.  As shown in Fig. 4, the filaments 13 issue from a dry spinning cell, pass round a feed roller 14 and under the freely mounted grooved rollers 15.  Other freely mounted rollers 16 are arranged alternately with rollers 15, and these are connected by a structure 17 which may be raised or lowered so as to adjust the tension on the filaments.  If desired the rollers 16 may be adjusted independently of each other in order that the amount of lap of the filaments on each roller 16 and the amount of stretch between each pair may be varied.  The outer peripheries of the rollers 15 are immersed in the liquid contained in the bath 18. The filaments pass to a washing device 19 and winding device 20. Threads having a variable denier along their length may be obtained by using rollers with grooves running in the axial direction whereby the softening agent is applied non-uniformly and the thread is stretched in a variable manner.  Specifications 277,089, 323,790, [both in Class 2 (ii), Cellulose &c.], 370,430, 371,461, 378,074, and 389,823 are referred to.