Paper recycling is an important way to reduce the waste stream, as paper waste is generated in huge amounts every year all over the world. The multi-step process recovers the maximum amount of reusable fiber from waste paper and converts it into new paper, cardboard, packing material, and other paper products. While paper recycling is not as stunningly efficient as glass and metal recycling, it is still an excellent way to conserve resources and help the environment.
By recycling paper, you reduce the waste of trees, water, and energy in addition to reducing the number of pollutants emitted by paper making plants. It is estimated that paper recycling is 40% more efficient than making paper from scratch, and when done in an ecologically sound way, it can even have environmental benefits. Ways to make paper recycling even more ecologically sound include using non-toxic chemicals to bleach it, alternative energy to power the factory, and recovered water to process the paper, rather than fresh, potable water.
Paper recycling starts with the consumer, who sorts various types of paper into bins for recycling. Almost all paper can be recycled, and companies that specialize in paper recycling pick up matte, glossy, and colored papers along with cardboard. If their facilities are unable to process certain paper products, they will usually sell those products to other companies who can. At the paper recycling facility, the paper is sorted into type and staples, paperclips, and other contaminants are removed.
Next, the paper is turned into mulch by being shredded and mixed with water. The mulch is pulped through long soaking and further blending, and then the pulp can be used to make fresh paper on paper making screens, molded into cardboard, or used to form other paper products such as recycled paper insulation. If necessary, the pulp is bleached before being molded into fresh paper, but otherwise, it is left plain.
Paper is rarely 100% recycled, because the fibers shorten as the paper is processed. It needs to be mixed with virgin pulp to make the paper stronger and more durable, and most paper has a lifetime cap on recycling ability: in general, paper can only be recycled four to six times before it is exhausted, and the shortened fibers will precipitate out of the slurry because they are unusable. Recycled paper has labels indicating the percentage of recycled content to guide consumers.
The leftover waste from paper recycling including inks, unusable fibers, and miscellaneous contaminants is called sludge. Sludge is sometimes buried in landfills, but it is usually spread on crops as mulch or burned to provide energy for the paper company. Although burning the sludge does emit pollution, it is sometimes seen as an environmentally sound method of powering a paper company and using the sludge efficiently, and in a high efficiency furnace with proper filtering, the pollution can be greatly reduced.