method of producing a genadelten material and device for implementing the procedure

摘要

1432881 Needling loom FIBERWOVEN CORP 23 May 1974 [20 June 1973] 23137/74 Heading D1R A previously needled fibrous web 14 undergoes transverse oscillation whilst being passed through the needling zone, the amplitude of the oscillation decreasing in the forward direction of travel. "Tracking", i.e. marking of the web with longitudinal scars caused by needling is thereby reduced. Preferably a "Fibrewoven" loom is used having 1 or 2 needle zones 28, 30 each zone comprising two pairs of needle boards mounted on rocker arms 32, 34 rocking about axes 36, 38. The needles of each upper board are point on point with and travel in a mirror image path of the corresponding needles of a lower board. Chains of fibre entanglement running longitudinally of the web are thereby produced. The transverse oscillation of the web imparts a sinusoidal displacement of decreasing amplitude to the chains so that they overlap. The web may be oscillated by roller 44 which is mounted for free rotation on shaft 52. One end 60 of the shaft is bifurcated for receiving the end of a crank arm 62, Fig. 4, carried on a crank 64. Collars 54 ensure that roller 44 oscillates with shaft 52. The web is drawn through the needling zone by driven rollers 48, 50. The web forms a festoon 46 between supply roll 10 and oscillating roll 44 to ensure its relaxation prior to needling. A bar or roller 150 may be provided to prevent the festoon flapping back and forth. It may be slightly weighted to adjust the tension in the web. As shown in Fig. 1 a second festoon, oscillating roller, needling zone and drawing rolls may be provided. In an alternative embodiment shaft 52 is stationary and supply roll 10 is oscillated. In the embodiment of Fig. 6 the web is fed from the supply roll 10 over driven roll 11 to J box 13 where it forms random plaits. The plaiting may be enhanced by replacing 11 by an elliptically shaped plaiter roll. The plaiting is said to produce transverse oscillation in the web as it passes over freely rotating roll 15 into the needling zone .Alternatively roll 11 or roll 15 may be reciprocated by the crank mechanism of Fig. 4.