Patent GB-1254850-A (GB)
Title: Method and apparatus for making a bias laid ribbon and product thereof
IPC: D21H25/00
Filed: 1968-09-26
Abstract: 1,254,850. Laminated tissue webs. CANADIAN INTERNATIONAL PAPER CO. 26 Sept. 1968 [27 Sept., 1967; 9 April, 1968], No 45673/68. Heading B5N. [Also in Division B8] A multi-ply ribbon is made from material having a greater strength in one direction than the other by unwinding a web 30 of material from a supply roll 29 and spirally wrapping it around a mandrel 35 to form a hollow tube, flattening the tube, and interlocking the fibres of opposed plies. In the resultant product adjacent plies have their directions of greater strength at an angle to each other. The method is applicable particularly to creped tissue webs, but also to webs of threads, yarns, synthetic filaments and scrim.  As shown in Fig. 1, the supply roll 29 is mounted in a carrier 43, and the web 30 passes via a guide roller 99 to the upper end of a convolute guide 101, shaped so that all parts of the web travel at the same speed. An endless stripper belt 109 engages the web at the upper end of the mandrel 35 and with the aid of rollers 117, 119 presses the web against the mandrel for helical travel around it. The tube formed remains on the mandrel until adjacent the nip of rolls 36 which operate with the belt 109 to pull the tube from the mandrel and flatten it. The mandrel tapers towards its end 135 to assist flattening of the tube. A carrier belt 38 is formed of woven wire with knuckles to compress the flattened tube at rolls 36, thereby interlocking the fibres of opposed plies at spaced points and providing a textured surface. The ribbon product is wound up on a roll 39 driven by a tangential drive 143 and a belt 144. Units 41 apply moisture to the belt 38 to assist the interlocking. The carrier 43 is rotated by a motor 63, via sprockets 59, 55. The mandrel is driven in the reverse direction at an identical angular speed to the carrier, so that it remains stationary with respect to the carrier support 45, by a connection to a shaft 95 via sprockets 85, 81, a shaft 77 and sprockets 89, 93. The speed of the belt 109 is correlated with the web via sprockets 125, 129 and 131. The nip rolls 36 may also be correlated with the web speed.  In a preferred embodiment (Figs. 4-19, not shown), suitable for rolls 29 of large diameter and high linear web speeds, a tangential driving means is provided for the roll 29 so that the web speed remains constant despite the changing roll diameter. The mandrel is formed as a cage structure of adjustable bars to reduce friction and preferably has an elliptical cross-section between a circular top cross-section and a linear bottom cross-section, and a plurality of endless stripper belts are provided. The flattened bonded ribbon may be further interlocked by passage between embossing rollers which glassine the fibres together. Creped tissue ribbons may comprise plies 21, 22 (Fig. 2) disposed symmetrically with respect to the longitudinal direction of the ribbon and with their fibres interlocked at depressions 142a and embossment areas 37. The helix angle may be 15-45‹. A four-ply ribbon may be made by using two separate webs, one forming the outermost plies and one forming the innermost plies, (Figs. 24-25, not shown). Multi-ply ribbons may also be made by overlapping several windings of the web. Winding may be carried out so that adjacent wraps of the web are overlapped (Figs. 26-27, not shown). The products may be dispersed between cover plies and/or reinforced with threads.