While several methods exist to recycle paper, they all follow
some plan to retrieve stock fibers from waste paper. Here are
details for one method, the Black Clawson pulping system. Waste
paper is dumped into a vat filled with water. This vat, called a
ragger, sloshes the paper around to break it up. If white paper
is going ot be made from the waste, chemicals are added to the
water to dissolve the ink. Large contaminants, called strings
and rags, settle out while the finer stock fibers flow into
another compartment. From here the stock gets pumped through a
large centrifugal cleaner. This machine spins the stock and
water mixture, forcing heavier contaminants to rim of the
centrifuge from which they can be removed. The unsettled mixture
is then filtered through a screen that traps unbroken bits of
paper and debris. The bits of paper, called flakes, can be
washed off and returned to the ragger for further processing.
Stock that makes it through the screens continues to the final
stages of the process. The fib