National Geographic : 1951 Jul
137 National Geographic Photographer Robert F. Sisson An Operator Guides the Master Machine; Robots Simultaneously Copy Its Work Albert Van-Stee, using a multiple carving machine, roughs out designs in six mahogany cocktail tables for the Widdicomb Furniture Company, Grand Rapids, Michigan. Despite its elegance, imported mahogany is the cheapest of all major cabinet woods. "Grand Rapids quality" is synonymous with excellent furniture. key raw materials. Wood is approximately one-half cellulose and one-third lignin. Lignin provides tannins and vanillin, and holds promise as an industrial chemical source. Lignin also is a base for hard, waterproof plastics, the stuff of radio cabinets, kitchen utensils, electrical equipment, combs and brush backs. From Cellulose Come Rayon, Film, Sponges Vastly more important for the present is cellulose. Cotton linters still are a source of the cellulose used as a chemical raw material, but four-fifths of our supply comes from trees. Hemlocks of the Northwest yield about 90 percent of wood-derived chemical cellulose.* In one major use, technicians treat cellulose chemically to provide a syrupy liquid they force through tiny holes into a special bath. There fine filaments form and harden into viscose rayon, one of our basic textile fibers. Cellulose also is the raw material of acetate and cuprammonium rayon. Mills weave rayon into all kinds of fabrics, from dress goods and underclothing to con- veyor-belt materials and cord to strengthen auto tires. Three-fourths of the cellulose used in rayon last year came from wood pulp. Photographic film, alike for Hollywood's costly motion picture cameras and for your inexpensive snapshot box, is made of cellulose acetate--so-called "safety film"-or from cellulose nitrate. Cellulose also is a base for plastics, including well-known celluloid. Cellophane, glassine, and greaseproof papers spring from cellulose. They protect, and at the same time display, foods, blankets, lamp shades, and hundreds of other items. World-renowned E. I. du Pont de Nemours & Company of Wilmington, Delaware, uses enormous quantities of cellulose as a raw material in its ramified operations. Six Du Pont departments make more than a dozen products based on this versatile ma terial, officers of the firm told me. Cellulose enters into Du Pont rayon, deter gents and sizes for textiles, pyroxylin-coated * See "Chemists Make a New World," by Frederick Simpich, NATIONAL GEOGRAPHIC MAGAZINE, Novem ber, 1939.