GB324527A - Improvements in or relating to the production of paper pulp and paper products - Google Patents

Abstract

324,527. Serebriany, M. M. Jan. 28, 1929. No Patent granted (Sealing fee not paid). Pulp, preparation of.-In the production of paper pulp, pasteboard, cardboard, paper and other pulp products, the fibrous materials of vegetable origin such as wood, wood bark, sawdust, moss, straw, reeds and cork, with the addition if desired of animal substances such as rags, leather waste, and the like are ground fine, preferably after being previously dried to a moisture content of about 4-6 per cent. They are then sorted to separate unground matter and swelled and stirred in cold water, or in hot water at 60‹-80‹ C., or in a mixture of equal quantities of turpentine and either benzine or petroleum. The mass may be rendered soft and resilient by the addition of about 2-4 per cent of caoutchouc or leather dust. Fillers such as asbestos, alumina, magnesia, chalk, leather dust, glass dust, meal, pumice stone, mica, or the like may be added to the mass, and the mass supplied to paper or pasteboard machines, or to presses to form plastic articles. Where turpentine, benzine, or petroleum are used for swelling, the mass may be worked up into paper or the like by rolling. An ordinary fibrous mass of wood or rags may be added to the mass before swelling. Where wood bark is used, a portion is treated with common salt solution before grinding, then ground up in a moist state, then treated in edge mills or the like. An equal mass of dry ground bark is then added with, if desired, ordinary fibrous material of wood, flax, hemp, or the like, and the mixture worked up into a very strong and elastic pasteboard, paper, or the like. Another method of treating wood bark consists of steaming in boilers at a pressure of 2-4 atmospheres before grinding.