PL20293B3 - The method of making plywood. - Google Patents

Description

The longest term of the patent until June 25, 1949 Patent No. 20291 describes a method of making plywood, consisting in leaching resins from wood veneers, and then gluing such leached veneers. Additional patent No. 20292 describes a method of making plywood, consisting in removing resins from wood veneers partially or wholly by boiling the wood veneers in water and then gluing as in Patent No. 20291. Additional Patent No. 20292 also indicates that the leaching process is similar, and often much better, if into water the necessary amounts of compounds of a more or less alkaline nature will be added, e.g. borax, water glass, sodium phosphate. During further research on the problem of removing resins, or their excess, from wood veneers, it was found that for this purpose, apart from the appropriate solvents, resins and water with aqueous solutions of compounds of an alkaline nature, and thus also water solutions bottoms, containing substances having the ability to dissolve, emulsify or saponify the resin. Such substances include moznatoine sulfone derivatives and polysulfone organic compounds of both the chain and ring series, often used under various trade names, such as, for example, Turkish oil, ordinary soap, monopoly soap, ncal and many others. . These substances may be both chemically pure and present as mixtures with other bodies, for example, with fats, fat solvents, etc., and, in addition, these substances may be used, as already mentioned, in an aqueous solution, alone or with addition of other substances with a weaker or stronger dissolving, emulsifying or disintegrating effect, such as hydroxides of alkali metals or alkaline earth metals, such as sodium, potassium, calcium, barium or strontium, sodium or potassium carbonate, sulfites or disulphites, borax, water glass, sodium phosphate, sodium acetate and L d. It has been found that the stronger the action of the compounds introduced into the aqueous solution is, the temperature may be lower, therefore it is desirable to facilitate the access of these compounds to the lives by Increasing the speed of circulation of the solution by known methods. The gluing of veneers can be made even after the veneers are washed out, or without tearing them, after drying or without stacks drying as described in the patent No. 20291. PL

Claims (2)

Patent conditions. 1. The method of producing plywood from veneers according to patent No. 20291, characterized by the fact that the wood veneers are cleaned from the resin in whole or in part by dissolving the resins, emulsifying, saponifying or splitting them with substances such as sulfone derivatives or polysulfone organic compounds, both chain and ring series, e.g. Turkish oil, ordinary soap, liquor soap, nekal in the presence of water, and then, after flushing or without splashing, dried or wet molds are coated they bind together with, for example, casein, albumin, glue, and then, when stacked in any direction, the fibers are pressurized in the press at elevated temperature, then cooled in the press or removed without cooling. 2. Product method according to claim A method as claimed in claim 1, characterized in that aqueous solutions of these substances are used with the addition of substances having a weaker or stronger dissolving, emulsifying or disintegrating effect. Henryk Piórnik. Printing by L. Boguslawski and Ski, Warsaw. PL