The Paper Mill Chemist (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 Excerpt: ...Common Name. White pine. Grey pine of Canada Spruce. Fir Balsam. Tamarack Poplar. Aspen. (Jottonwood Willow. Beech. Maple. White birch Paper birch Buckeye Sweet gum Cypress. Hemlock Chestnut Basswood Locust. From the point of view of the pulp-maker, the more important constituents of wood consist of mineral matter, resin and moisture, in addition to cellulose and incrusting matter. The percentage of mineral matter in the form of ash is given in Sharpies. table. The percentage of resin in wood has been studied by Ulbricht, whose results are given in the accompanying table: --TABLE XXXIII. Parts Of Resin Per 100 Parts Of Wood (abies Exoelsa). The figures were obtained by extracting the wood with alcohol, so that everything soluble in alcohol is reckoned as resin. Resin is readily acted upon and saponified by alkaline liquids, so that where the wood is treated with alkalies, as in the soda and sulphate processes the percentage of resin is only of secondary importance. Resin, however, influences the properties of mechanical pulp, and also sulphite pulp, as the acid sulphite liquors have but little action on resinous substances. As will be shown later, sulphite pulp invariably contains a much larger proportion of resin than soda pulp. The quality of the pulp will also be affected by the distribution of the resin, that is to say, whether it is evenly distributed throughout the mass or localised at certain points. Not only does alcohol extract substances from wood, but other solvents, such as water, remove some of its constituents, such as tannin, gums, mucilage, sugars and other carbohydrates. The accompanying table gives the extract on treating wood successively with water, ether, and alcohol: --Finally, there is the question of moisture. Coniferous trees in gener.