![]() The Editors of Encyclopaedia Britannica This article was most recently revised and updated by Barbara A. ![]() The chief European pulpwoods are Norway spruce, Scotch pine, and various hardwoods. Spruce, balsam fir, and hemlock are considered the best woods for sulfite and mechanical pulping several varieties of pine are used for sulfate (kraft) pulping hardwoods are pulped by all of the pulping processes. “Semichemical” is a term applied to a process of cooking followed by mechanical treatment. Chemical pulps are classed as unbleached sulfite (strong and news grade), bleached sulfite (dissolving and paper grade), bleached and unbleached sulfate (kraft), and soda. Mechanical pulp, generally called groundwood, is usually produced by a mechanical grinding process and is not further classified except as fine, coarse, or bleached. Wood pulps may be classified into two general groups, mechanical and chemical. In the rain-soaked Indian state of Meghalaya, locals train the fast-growing trees to grow over rivers, turning the trees into living bridges.
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