GB1326679A - Apparatus and method for levelling tow - Google Patents

Abstract

1326679 Levelling tow TURBO MACHINE CO 19 April 1971 [10 Aug 1970 26684/71 Heading D1F A process for improving the levelness of a moving band of filamentary tow comprises (a) advancing the tow while under a tension insufficient to cause filament breakage (b) laterally separating some of the filaments with respect to other in the tow band whilst increasing the tension of the band, (c) decreasing the tension in the filaments, (d) making lateral separations of the filaments in the tow band whilst increasing the tension in an amount insufficient to cause breakage. The above steps are repeated intermittently. The process may be carried out in an apparatus comprising a plurality of rods moving in paths in a direction to cause them to engage the tow, each rod having a plurality of V-grooves on its surface, each rod intermittently engaging a face of the tow with its grooved surface and dividing the tow into a plurality of bundles and laterally displacing the filaments thereof and diverting the tow from its path, the grooves on each rod being out of phase with the grooves on the preceding and the succeeding rod. A suitable apparatus is shown in Fig. 1 and comprises a creel frame 10, guide bars 12, 14, 16, 18, 20 and 22, and beaters 26 and 28. Each beater is provided with rods each having a grooved surface (if parts 58, 59 and 60 of Fig. 2 (not shown)). The beaters rotate in the opposite direction to that of the tow 24 and the grooved surfaces engage the tow and separate it into a plurality of filament bundles. The rods are arranged so that the grooves are transversely out of phase (Fig. 4, not shown). The lateral separation of the tow may also be achieved by using a plurality of air jets located transversely across the tow band. or by penetrating the tow band with blade having V-shaped sharp-toothed serrations.