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What's in your trash?
What is the number one material in the solid waste stream?
Look around your school classroom. What do you see? Books?
Posters? Cardboard Boxes? Notepads? Bulletins boards covered
with construction paper? Paper is everywhere and is what Americans
throw away the most.
For every 100 pounds of trash we throw away, 35 pounds is
paper. Newspapers take up about 14 percent of landfill space,
and paper in packaging accounts for another 15 to 20 percent.
The paper we use has many forms - ragged, glossy, thin, thick;
it can be a newspaper, piece of junk mail, food package or
even the stuffing in diapers. Most paper products are made
from trees that have been cut and pulped, though paper can
also be made from old cloth or grass.
How is paper made?
Papermaking uses a renewable resource: trees!
The first step to making paper is to harvest trees. Companies
plant trees specifically for papermaking and once a tree
is cut down, another is planted to replace it.
Trees are harvested and delivered to paper mills. Paper
mills use every part of the tree that they can. The bark
and roots are often burned for energy. The rest of the tree
is chopped into small chips for pulping. Pulping is a chemical
process that separates the wood fibers from lignin and other
wood parts.
Pulp is the soft, spongy part of a tree. Lignin is the
glue that holds a tree together. If lignin is left in a
paper product, the paper turns yellow and brittle when it’s
exposed to light. After it goes through the pupling process,
paper is brown - just like grocery bags. High quality papers
are whitened with bleach and sometimes coated with clays
and other materials to give them a glossy finish.
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