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Show HOW PAPER IS MADE Paper, in some form, is so common in American homes that one does not give much thought as to how or from what it is made although the value of paper products manufactured manufactur-ed annually in the United States amounts to about a billion dollars. At one time spruce and balsam were the principal woods from which paper was made but the gradual decrease in the stands of these woods caused the United States Forest Products Pro-ducts Laboratory, Madison, Wisconsin, several years ago to begin investigating other woods for paper making. The Forest Products laboratory has found that good pulp for various kinds of paper can be made from many kinds ot wood, up to the present time having satisfactorily tried out over 90 different species. Years ago it found that good, strong, white pulps could be made from; the pines, widely distributed throughout the southern states. Up to that time most of the pulp-wood had come from the northern part oi the United States. A recent laboratory experiment shows that a good pulp for containers and building papers can be made from blackjack oak, a wood never before thought of in connection with paper making. In making paper from wood one of two processes is used, the mechanical or the chemical.. In the formfer process the wood is ground into a fine pulp by means of a large grindstone. grind-stone. This ground wood is used in many cheaper paper grades, for example, newsprint paper, where it is mixed with 20 per cent of chemical pulp, to give it strength. There are three common chemical processes of pulping wood, in all or which chemicals are mixed with wood, cut into small chips, and cooked in covered steel tanks, much as vegetables are cooked in a pressure cooker. When the chips are softened they are run through other machines where the lumps are broken and the fibers washed and often bleached. When the pulp, made by either method, goes to the paper-making machine, ma-chine, it is about 99 per cent water. As it goes through the machine the water is taken out by gravity and steam-heatea rollers and the pulp comes out at the end of the machine as finished paper. The chemical process makes the better grades of paper, such as writing and book papers. The Forest Products laboratory is constantly trying out new woods for paper as well as new and varied manufacturing manufactur-ing processes. o |
