GB941874A - Strand annealers - Google Patents

Abstract

941,874. Tow-annealing apparatus. MONSANTO CHEMICAL CO. Sept. 14, 1962 [Oct. 16, 1961], No. 35146/62. Heading B5B. Apparatus for annealing a tow comprises a three-stage annealing chamber having means in the first stage for directing streams of annealing fluid against opposite sides of the tow, means in the second stage defining a throat through which moving annealing fluid carries the tow, means in the third stage for carrying off the annealing fluid, and means for forcing the annealing fluid through the chamber. In apparatus as shown, rolls 10 advance a tow 12 to the chamber 13 and rolls 11 carry it away. Fan 40 moves air heated in heating chamber 42 through the ducts 18 and 19 into the first stage of the treating chamber 13, comprising upper portion 14 and lower portion 15, in which the heated air alternately impinges on opposite sides of the moving tow via the ducts 22, 22a, 23, 23a, 24 and 24a which are positioned at acute angles to the path of the tow so that air flowing from these ducts urges the tow along its path. Exhaust ducts 25, 26, 27 and 28 carry the heated air from opposite sides of the tow from the duets 22, 22a, 23 and 23a directly from the first stage to the third stage, so that the heated air flows through the tow to uniformly anneal all its fibres. Air flowing through ducts 24 and 24a passes through the throat 31, defined by baffles 29, 30 at high velocity, carrying the tow through the throat, but without the positive feed that would be exerted by rolls so that the filaments in the tow 12 are free to shrink or contract to the maximum possible extent beyond throat 31, the rolls 11 being driven at a slower speed than rolls 10. Deflectors 32 and 33 in the third stage direct the stream of air from the throat towards ducts 34 and 35, and air exhausted from these ducts is directed back through duct 43 to the heater 42. Joints 46 and 47 permit removal of upper portion 14 for lacing up the apparatus and for maintenance. Air leakage into and out of the annealing chamber 13 can be controlled by valves 50 and 51. With valve 50 opened and valve 51 closed air is drawn into the system at valve 50, and an equal quantity of air is expelled through the space between sections 14 and 15 where the tow enters and leaves the chamber 13, the effect being to scrub ambient air from the tow and ensure more uniform annealing thereof. With valve 50 opened and valve 51 closed, heated air is purged through valve 51 and an equal quantity of air enters through the openings in the annealing chamber 13, producing non-uniformity in annealing which is useful in obtaining novelty effects.