GB433962A - Improvements relating to veneer sheets - Google Patents

Abstract

433,962. Veneers. ELMENDORF, A., 211, East Chestnut Street, Chicago, U.S.A. Feb. 26, 1934, No. 6163. [Classes 145 (i) and 145 (ii)] Veneer is subjected to a pressure in excess of the crushing strength across the grain of the wood, and to a temperature above the boiling point of water but below that at which the wood scorches or tarry products are obtained ; for example, pressures of 900-1200 Ibs./sq. in, and a temperature of 140‹ C. may be used. The moisture content of the veneer is reduced before treatment to below the fibre saturation point-e.g. to 10-15 per cent of the oven dry weight-to prevent splitting or darkening of the veneer during treatment. The pressure is relieved and re-applied at intervals to allow escape of the moisture generated by the heat treatment. The pressure plates are polished and may be chromium plated ; the surface of the treated veneer takes on a high polish, so that sanding and varnishing may be dispensed with. By the treatment the pores of the wood are closed, so that no filler need be applied if the veneer is to be coated with varnish &c. ; further, adhesive does not penetrate through the veneer to cause staining. Veneers thinner than those usually employed and densified by this treatment can thus be employed, and are stated to lie flat on a surface without bulging. The veneer may be applied to a base by cold press glueing or by hot pressing with film or powder glue. The veneer may be coated with a layer of adhesive, such as rubber latex containing casein and a vulcanizing agent, which is allowed to dry; when the veneer is to be applied, the adhesive is softened by benzene or other rubber solvent. The body to be veneered may be similarly treated, or the adhesive may be applied when the veneering is performed.