Patrick Ball, age 14, of Tucson, Arizona, for his question: 

How is wood pulp made and used?

Wood pulp is just about the most versatile substance in our everyday lives. There are dozens of recipes for making it and thousands of uses for the finished products. But the basic ingredient in all the various products of wood pulp is cellulose, a tough fabric created in abundance by the plant world.

For centuries mankind has been mashing chips of wood into soupy pulps for making paper. The basic recipes were simple and most of the papery products were not expected to be either strong or very durable. Lately our clever chemists have added surprising new intredients to the old recipes. Update paper pulp products may be waterproof, fireproof or acidproof. Some of them are strong enough for making furniture or durable enough for roofing houses. Others become pliable fabrics for curtains and clothing. These and other wood pulp products are taking over the duties of wood and metals, china and glass.

The basic ingredient in paper and all these other products is a gift of the plant world, a tough carbohydrate chemical called cellulose that plants manufacture from air, water and sunlight. Fibers of cellulose are extremely durable and plants use them to build the walls of their boxy cells. Cellulose suitable for making useful pulps is found in cotton and rice, in straw and cornstalks, in grassy hemps and jutes. But about 90 per cent of our papermaking fibers are actually made by processing the lumber of woody trees.

Natural cellulose swells when wet, but refuses to dissolve in plain water. It is almost indigestible and few chemicals can break down the structure of its sturdy molecules of hydrogen, carbon and oxygen. Strong caustic and acid chemicals are used to mash chips of sturdy wood into soupy pulp. Some recipes mix vats of washed wood chips in steamy baths of calcium bisulfite. Other recipes process the wood chips in baths of caustic soda or caustic soda and sodium sulfide.     

Many different products can be made from basic wood pulps. To make paper, the mushy mash is rinsed and Squeezed dry, pressed into thick sheets or rolled into tissue thin layers. It can be bleached or dyed, waxed or glossed. The cellulose from wood pulp can be treated with acetic acid to make acetate for film and textiles. Ethyl cellulose is tough enough for making luggage and football helmets. Telephones and plastic toys are molded from wood pulp cellulose propionate. Other recipes employ cellulose in making paints and explosives, shiny lacquers and glossy man made leathers, cellophanes and countless other plastics. And paper made from basic wood pulp can be shredded and resoaked to make papier mach k. This moldable material can be stiffened with lime or clay, glue or borax, sand or salt.     

The list of products made directly or indirectly fror basic wood pulp grows longer every year. As more recipes are developed for wider uses of wood pulp, we shall need more trees. We must be sure to replant our lumbered forests for the future. And those same trees that supply us with so many wonderful wood pulp products also replenish the air with fresh oxygen from their leafy foliage.