GB688219A - Improvements in or relating to the liquid treatment of thread - Google Patents

Abstract

Artificial thread (e.g. viscose rayon) is treated by applying treating liquid to the surface of an advancing thread helix by means of a stationarily held or anchored surface-contacting and contour - following liquid - applying and -distributing means which is in contact with a plurality of consecutive turns of thread of the helix. In an example, a freshly-coagulated viscose rayon thread 20, Fig. 4, is advanced and stored on a reel 33 which is inclined about 5 degrees from the horizontal downwards from the discharge end. A treating solution is discharged <PICT:0688219/IV (a)/1> <PICT:0688219/IV (a)/2> from the tube 38 on to the top side of the reel near the thread-discharge end thereof. The reel 33 is of the type described in Specifications 413,414, [Group IX], and 545,250. It is internally heated by introducing steam or hot water through the hollow shaft 34 and exhausting the fluid through the concentric shaft 35. The distributing means 36 consists of a relatively thin, light-weight cloth made of chemically resistant fibres such as a polyacrylo-nitrile yarn or glass fibre cloth impregmated with a vinyl chloride polymer. One edge of the cloth 36 is anchored to one side of the tray 26 by the pin 37 while a portion of the cloth opposite the anchored edge is supported by the applied liquid present on the rotating thread helix over an arc of about 20-60 degrees. The treating solution discharged from the helix is collected in the tray 26. In another example the cloth distributing means 36 is substituted by a brush-like distributing means consisting of threads or ribbons sealed at one end into a block of polymeric thermoplastic material, the brush being positioned adjacent to the ascending side of the helix and making contact with the helix over an arc of about 45 degrees. The peripheral speed of the reel in this example is 77-160 metres per minute. In a further example the peripheral speed of the reel 44, Fig. 6, is 300 metres per minute, i.e. sufficiently high to cause applied liquids to be thrown off an unshielded thread helix by centrifugal force, but the liquid delivered from the tube 48 is prevented from being thrown off the reel 44 because the latter is encircled almost completely by the thin, light-weight resilient methyl methacrylate resin band 45 supported by the shafts 46 and 47. In a further example the external distributing means consists of three separate sheets of glass fibre cloth impregnated with a vinyl chloride polymer which contact the helical thread package over an arc of about 90 degrees and are mounted as in Fig. 4. The cloth sheets are spaced apart and distribute over three separate parts of the thread helix three different treating liquids delivered by three tubes corresponding with the three cloth distributers. The reel in this example has a peripheral speed of 150 metres per minute. In a further similar example the peripheral speed of the reel is about 300 metres per minute and three bands encircle the helix in the manner shown in Fig. 6. The distributing means may also be a cord having a denier of about 2001 contacting the ascending side of the thread helix and extending upwards from the thread-discharge to the thread receiving end of the reel. The process is particularly applicable for conditions of high thread speed and/or low thread tension (caused, for example, by relaxation of the thread during treatment at elevated temperature) and enables the consumption of treating liquids to be reduced.