GB734324A - Improvements in and relating to the treatment of thread, particularly viscose rayon thread, with fluids - Google Patents

Abstract

<PICT:0734324/IV (a)/1> <PICT:0734324/IV (a)/2> Threads, particularly freshly formed artificial threads, are subjected to treatment with fluids by forming each thread into a helix, heating the helix by circulating a heat-transfer fluid through the interior of the helix, passing a thread-treating fluid in heat-exchange relation with the heat-transfer fluid to the interior of the helix, and applying the heated thread-treating fluid to the thread helix. If desired the heat-transfer fluid may also be applied to the helix so as to serve as an additional thread-treating fluid. The process may be employed in the continuous production and treatment of viscose rayon thread. The apparatus employed incorporates a thread-advancing reel comprising a hollow shaft, two reel members mounted for rotation on the hollow shaft and having at their peripheries longitudinally extending bar members with the bars of one member interdigitating with the bars of the other member, means in the hollow shaft to enable a treating fluid and a heat-transfer fluid to pass therethrough in heat-exchange relationship, and means for allowing the heated treating fluid to pass from the hollow shaft into contact with the thread on the periphery of the reel. As shown in Fig. 1, viscose is extruded from a spinneret 10 into an acid coagulating bath 11 to form a thread 12. The thread is drawn through opening 13 in trough 14 by a take-up reel 15 and then passed over a guide 16 in an opening 17 of trough 18 to a thread-advancing reel 20. After being treated with liquids and being dried on reel 20, the thread is led to a cap-spinner 24. As shown in Fig. 3, the reel comprises two reel members 30, 31, which rotate about axes that are offset and askew to each other. The reel members are mounted on a hollow shaft 35 and each member has a periphery of longitudinally extending bars 32, 33, the bars 32 interdigitating with bars 33. The shaft 35 has a reel-supporting yoke with a conically shaped flange 37, one end of which has an eccentric sleeve 38. The axis of the sleeve is offset and askew to the axis of shaft 35. A heat-transfer fluid supply conduit 46 leads to a sealing cap 45 and a nipple 44 which is threaded into a housing 42. Treating-fluid conduits 47, 48 are located in housings 40 and 42. A concentric tube 50 is provided within the hollow shaft 35, and both tube 50 and the shaft 35 open into the interior of the reel itself. A driving gear 52 is mounted about shaft 35 and secured thereto. Rotation of the reel causes the helix of thread to advance over the bar members 32, 33. The reel shaft 35 supports the concentrically mounted reel member 30. The eccentric reel member 31 is secured to a flanged hub 60 which is mounted for rotation about the eccentric sleeve 38. The reel interior is subdivided into two sections 70, 71. Treating fluid from conduit 47 passes through chamber 74 and the annular space within shaft 35, and thence through passages 66 into section 71 from which it flows under the centrifugal force, due to reel rotation, through passages 73 to the exterior of the reel and to the thread being advanced over the reel. Fluid in the tube 50 passes into section 70 and the condensate formed in this section flows through passages 72 to the reel surface. The heat-transfer fluid admitted through conduit 46 may be steam and to this may be added a lubricant oil emulsion through conduit 48. To complete the regeneration of the viscose rayon thread on the reel 20, a measured amount of dilute sulphuric acid is admitted through conduit 47 and this flows through passages 73 to the thread helix. The dilute acid on the thread is then washed out by a subsequent treatment with condensed water containing an oil emulsion on a further portion of the reel to which the acid-laden thread helix has advanced. The thread is then dried as it travels over the last few inches of the heated reel. The reel is preferably arranged at 5-10 degrees to the horizontal so that treating liquid will flow toward the thread take-up end of the reel and against the advancing thread helix. Excess of acid solution from reel 20 is collected in trough 18 (Fig. 1) which has an outlet 19 directed on to the take-up reel 15. The dilute acid solution dilutes the bath acid on reel 15 and tends to prevent the deposition of salt crystals. If desired, the thread, after leaving the reel 20, may be led to other reels for further treatments, e.g. desulphurizing, before passing to the winding device.