Oct 28 2008
Background
How is Paper Made
How Many Times Can Paper Be Recycled
What Happens
to Paper and Cardboard When it Goes to be Recycled
Separation
Baling
De-Inking
and Processing
Background
Paper and cardboard are made from cellulose fibre that comes from trees. The
trees are sometimes grown in specially developed plantations but they also come
from virgin forest. With 13 mature trees being used to make a single tonne of
paper it is important recycle paper and retain trees and forests for the
purposes of biodiversity, animal habitats and combating climate change. Some
paper is made from other fibre sources like cotton or hemp.
How is Paper Made
In order to make paper, the trees are chopped down and cut into small wood
chips. The chips are mechanically and/or chemically treated to release the
cellulose fibres and for a pulp. The pulp is mixed with large quantities of
water to make a mush or slurry that is passed over a moving mesh. The water
passes through the mesh leaving the fibres behind in a damp, rough form of
paper. The damp paper is passed through a series of rollers to flatten and dry
it. The paper is then rolled onto large spools with the huge rolls then sent for
cutting and packaging into the final paper product.
How Many Times Can Paper Be Recycled
Each time paper is recycled the cellulose fibres get smaller and lose
strength. This means new fibres always have to be mixed with the recycled
content. Paper can usually be recycled 8 times.
What Happens to Paper and Cardboard When it Goes to be Recycled
Recycling of plastics happens in 3 stages:
- Separation
- Baling
- De-Inking and Processing.
Separation
In mixed recycling streams the paper and cardboard is separated from steel,
plastics, aluminium and other materials sent for recycling. The paper items may
be further separated into types of paper that require different processing
steps. For example, cardboard milk cartons require removal of their plastic
coating but newspapers don't.
Baling
Different types of paper and cardboard are compressed into large bales for
transport to different processing plants.
De-Inking and Processing
Different types of paper sent for recycling will require different processing
methods. Printed paper may need treatment with special detergents or soaps to
remove the ink. The waste paper is mixed with water to break it down into a
slurry of fibres. The slurry is screened to remove contaminants like plastic,
staples, paper clips, tape and string. The cleaned slurry is then mixed with new
fibres to produce new paper.
Source: AZoCleantech