The Recycling Process
Ever wondered what happens to waste paper when it is taken away by the
contractor for recycling?
Well, here are the steps involved in the recycling process:
Successful recycling requires clean recovered paper, with no
contaminants such as food, plastic and metals
Before being transported to a paper mill, the waste paper dealer collects
recovered paper from the office and wraps it into tight bales
Different paper grades (A4 paper, newspapers, corrugated boxes etc.) are
kept separately
A pupler, which contains water and chemicals, chops the recovered paper
into small pieces; heating it further breaks down the paper into
individual fibres. The mushy pulp is then forced through screens; small
contaminants are removed at this stage
Heavy contaminants, such as staples and paper clips, are spun out of the
pulp, while lighter materials collect together and are removed
Sometimes the pulp must undergo de-inking to remove printing ink or sticky
materials. Air and soap-like chemicals cause ink to loosen from the pulp
and float to the top of the mixture. The sludge which forms on the surface
is then removed.
During refining, the pulp is beaten to make the fibres swell; ideal for
papermaking. Colour stripping chemicals remove dyes from the paper; if
white paper is to be made, the pulp may be bleached using hydrogen
peroxide, chlorine dioxide or oxygen.
Finally the clean pulp is ready to be made into paper. The pulp is mixed
with water and sprayed onto a flat wire screen; the water drains from the
pulp and the recycled fibres bond together. The sheet is heated and dried
and then the paper is wound onto a large roll, ready to be converted into
different types of products.