Paper is made of millions of tiny fibres. The fibres are cellulose, a substance from the cell walls of plants. The cellulose used in the paper today comes mostly from trees.
When the bark of a tree log has been stripped off, the wood is ready to be turned into pulp. Pulping is done either by grinding up the wood or by cooking it with chemicals. Some pulping methods use both grinding and cooking.
The wood pulp is then screened and washed to clean out impurities and chemicals. It may then be bleached to make the paper whiter so that printing or writing shows up better on it.
In the next step, the pulp is beaten in a large mixing machine and mixed with water. The beating frays the fibres, which helps them mat together. Starch, clay, or other materials may be added to improve the surface of the paper for printing and writing.
The pulp then goes into a machine called a Jordan refiner, where the fibres are trimmed evenly. At this stage, the pulp consists of 99 per cent water and 1 per cent fibre. It is now ready to go into the paper-making machine.
In this machine, water drains out of the pulp through a screen, and suction pumps remove more water. The screen vibrates to make the fibres interlock and mat together. The wet mat then passes under a roller that presses it down into a smoother sheet.
The sheet goes through a series of press rolls, which squeeze out water and make the paper dense and smooth. Then it travels through a series of heated drums called driers. At this time a coating can be applied to make the paper smooth and shiny. Paper comes off the machines in large rolls. It is trimmed to take off the rough edges and cut to the desired width.
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