GB1469276A - Process for producing sliced veneer - Google Patents

Abstract

1469276 Forms of wood SADASHIGE FANCY PLYWOOD INDUSTRIES CO Ltd 18 March 1974 [17 Sept 1973 3 Oct 1973 30 Oct 1973 26 Nov 1973 28 Nov 1973 12 Dec 1973 15 Dec 1973] 11980/74 Addition to 1412903 Heading B5L A process for producing wood veneer comprises providing a plurality of individual flitches, e.g. a, b, c, d, e, f, Fig. 5, of log material, smoothing the surfaces of the flitches which are subsequently to be glued, applying a hydrophilic adhesive to the smoothed surfaces, gluing the flitches at the adhesive-bearing surfaces to form a composite flitch, as shown, and slicing said composite flitch to a desired thickness to produce a veneer, all the process being carried out while maintaining the moisture content of the wood flitches above the fibre saturation point. As described the flitches are produced by sawing or slicing a log lengthwise and transversely in various ways, or by cutting a log to have a prismatic section, e.g. as in Fig. 58, and adding pieces to give the flitch a generally square section. The flitches are joined by hydrophilic adhesive which may be an underwater curing polyurethane adhesive and/or a moisture curing epoxy resin though other thermosetting and thermoplastics resins are specified. The adhesive may include a dye or pigment, e.g. alizarine red S, methylene blue, Sudan II, azo type dyestuff, cyanine type dyestuff, titanium white, red iron oxide, or chrome yellow. When a die is used it may diffuse into the flitches by capillary attraction. The veneers may be united to form plywood, or adhered to a substrate of wood, plywood, hardboard, paper, plastics sheet, cement board, ceramic tiles, or metallic sheet, by hot pressing using an adhesive such as phenolic, resorcinol, urea, melamine, epoxy, unsaturated polyester, polyurethane or diallylphthalate resin, PVA, polymethylmethacrylate, polystyrene, polyvinyl acetal, polyvinyl butyral, methylcyanoacrylate nylon, polyacetal, ethylene/vinyl acetate copolymer, vinyl acetate emulsion, ureavinylacetate emulsion, styrene-butadiene rubber, nitrile rubber, polychloroprene, polybutadiene, polyisobutylene, polyisoprene-isobutylene, Thiokol (Registered Trade Mark), or polyacrylate resin. The flitches may have different shrinkage coefficients and be arranged in sub groups within the composite flitch so that all the sub groups have the same average shrinkage. When the flitches are of different woods flitches of wood which splits easily such as kalopruax, ash, zelkova, teak, elm, kokko, or red oak may be at least partially surrounded by flitches of woods which do not split easily such as saperre, moabi, American walnut, dao, rose wood, birch, and camphor tree. One or both faces of a flitch, Fig. 36, may have a groove 10 cut therein by a router. The groove may subsequently be filled with a thermosetting or thermoplastics resin, which may include a pigment or dye to provide an ornamental line in the veneer.