GB772172A - Improvements in method and apparatus for moulding corrugated board and corrugated paper board - Google Patents

Abstract

772,172. Faced corrugated board &c. PACKAGING MATERIALS CORPORATION. Oct. 20, 1952 [Nov. 3, 1951; Nov. 3, 1951; Nov. 3, 1951; Sept. 27, 1952], No. 26256/52. Class 96. In the production of packaging material, e.g. as illustrated in Fig. 21, pulp from a flow box 4 Fig. 1, is formed on a cylinder 1 having a grooved or corrugated surface, subjected to suction of internal boxes 6a, 6b, 6c and 6d, the suction, which is weakest in the first box 6a, acting through holes 3 in the grooves and through an outer, finer wire-cloth and an inner, coarser wire-cloth, both wire-cloths being corrugated, or of zig-zag shape to conform to the shape of one surface of the corrugated fibrous ply 26 to be produced, but not to fill completely the grooves of the cylinder 1. Water is expressed from the web by adjustable, spring-pressed rollers 11, 13, 15, one of which may be ribbed to conform with the grooves of the cylinder 1. On starting, an air blast 10 blows the pulp web 25 off the cylinder on to a conveyer 9 which carries it into a heated-air drying-chamber, a second conveyer below the first taking it out again and directing it to guide rollers and into a gluing &c. appliance where one or two facing plies 81, 83, Fig. 21, are adhered with the aid of heat. The adhesive 82 is applied to the plain plies as spots or as spaced lines transverse to the corrugations, to facilitate bending the finished product. The ribbed parts of the corrugated ply may be scored transversely, or with two sets of scorings each at 45 degrees to the line of the ribs and at 90 degrees to each other. The density and thickness of the corrugated ply 26 are regulated by the pressure applied by the roller 13 &c. In modifications: (1) rollers 11, 13, 15 are substituted by an endless belt pressing on the cylinder 1; and (2) a suction wet press is interposed between the cylinder 1 and the drying-chamber. The corrugated ply 26 may be impregnated with synthetic resin, lignin, or sodium silicate. Specification 704,928 is referred to.