How do they make paper? Is it always made from trees? asks John David Ketchum, age 6, of Phnom Penh, Cambodia.
In August, it seems like we’re surrounded by paper. Before the start of a new school year, stores aisles are blocked by stacks of notebooks, binder paper, construction paper, and Post-it notes. Once school starts, there’s more paper: forms to fill out, exams to take, reading lists to take home.
But while most of the paper around us was made from wood, the paper we pay for it with wasn’t. Whether it’s a one-dollar bill or a hundred-dollar bill, U.S. paper currency is actually 75 percent cotton and 25 percent linen. So the folded-up money in our wallets is made from fibers usually spun into fabrics. Which explains why you can throw your laundry in the washer, dry it, and pull a still-usable ten out of your jeans pocket. (A tiny care label on each bill might help.)
But making paper currency out of cotton and linen isn’t odd. Some 2,300 years ago, people in Egypt wrote on pressed strips of a swamp plant called papyrus (and where we got the word “paper.”) Others painted words on stretched, dried animal skins (“parchment”). In the beginning, people scratched symbols on stone, a tradition we continue today on buildings and monuments. Writing was also etched onto hammered-out sheets of copper and brass; today, we engrave plaques and rings.
Until the mid-1800s, most paper was made from cloth rags, beaten until they fell apart. The cloth fibers soaked in a vat of water, spread into a thin layer, and drained on screens.
But when people turned to making paper from wood, a new industry took off. The basic process: Trees are sawed down and cut into logs. The logs are moved into a huge, turning drum, which shaves off their bark. Then the bare logs enter a chipper, and are whittled into small pieces.
Next, mechanical grinders or strong chemicals or both break the chips down into individual wood fibers. The yellowish or brown mush of wood fibers is called “pulp.” (Look closely at a brown paper bag, and you’ll see the individual strands.) If the pulp is destined to be white paper, it’s bleached.
The wood fibers are washed to get rid of chemicals, then beaten and rubbed. Finally, the fibers may be treated with a water-resisting material like rosin. That way, ink won’t soak through your notebook paper. If the paper will come in colors, dye is added now.
Then the fibers, mixed into water, flow across a moving wire screen, collecting into a wet, draining web. Presses flatten the pulp into a sheet, which is pulled over huge drums and dried. The dry paper, up to 30 feet wide, is rolled out and cut to size.
Many papers are made from used, recycled paper, saving trees and reducing waste. Besides wood, cotton, and linen, modern paper is also made from bamboo, straw, hemp, and even sugar cane waste. For more on papermaking using wood, visit www.tappi.org/paperu/all_about_paper/paperMade.htm.
