By Howard J. Bennett
The next time you grab a sheet of paper to do your homework, remember that the product you’re writing on used to be a tree. Most kids know this, but what you may not know is how a tree is turned into paper.
Trees are made of cellulose fibers, organic compounds, and a natural glue-like substance called lignin that holds everything together. Cellulose makes up about 50% of a tree, and this is the part that’s used to make paper. But first you need to separate the cellulose from other wood parts.
Paper mills get their wood from two sources: small trees that are harvested for that purpose and wood scraps from larger trees that were sent to sawmills for lumber. The bark is stripped off, and trees are put through a chipper, which grinds the wood into small pieces that are easier to process.
Once the wood has been chipped, it’s converted to wood pulp. This can be done mechanically or chemically. Depending on the method used, pulping requires a combination of steam, pressure, chemicals, grinders, and in some cases, bleach. Unbleached pulp is produced for bags and boxes. Bleached pulp is produced for paper that will be used for writing or printing. (Bleached wood pulp is a gooey and white—like mashed potatoes, but without the yummy taste.)
When the pulp is finished, it’s mixed with water and sprayed onto large, moving screens. The water drains through the screens and lets the cellulose fibers stick together to become paper. The paper moves at high speeds through a series of presses and driers. Additives are added to strengthen the paper. The finished paper is wound on rolls and cut to size.
Now that you know the basics of making paper, I have a question for you.
True or False—You can buy paper that’s made from elephant poop?
True. Depending on the season, an elephant’s diet consists of grass, leaves, twigs, bark, vines, roots, flowers, and even fruit. However, since vegetation can be difficult to digest, lots of plant fiber comes out of the elephant’s body without being broken down. By cleaning and removing the actual waste from undigested plant matter, you can harvest enough cellulose to make paper.
Thanks to the enterprising minds of some eco-friendly folks, you can buy paper made from the poop of a number of animals. The last time I looked, you could not only buy paper made from pachyderm poop, but also from pandas, kangaroos, sheep, bison, and reindeer. Does that give you any ideas for a birthday present?
© 2012 Howard J. Bennett. All Rights Reserved.
(First published in the Washington Post 3/29/10.)
For more KidsPost articles and lots of other cool stuff,
please visit Dr. B’s website at www.howardjbennett.com.