Paper Recycling

Paper, the most recycled material in the Blue Box program, is sorted at MRFs into various grades and types, including old newsprint, mixed waste paper, old corrugated cardboard (OCC), etc. Manual sorting and various screens are used to sort paper. Once the paper has been sorted it is shipped in bales or loose to various end-markets. End-markets produce a variety of products from waste paper including new paper, egg cartons, paper plates and other paper products.

While there are differences in the recycling processes used by end-markets based on the type of paper being used (OCC, ONP, mixed waste paper) they all involve separating the fibers so they can then be reformed to create new paper. The process most commonly includes the following steps:

Pulping: Adding water and applying mechanical action to separate fibers from each other.
Screening: Using screens, with either slots or holes, to remove contaminants that are larger than pulp fibers.
Centrifugal cleaning: Spinning the pulp slurry in a cleaner causes materials that are more dense than pulp fibers to move outward and be rejected.
Flotation: Passing air bubbles through the pulp slurry, with a surfactant present, causes ink particles to collect with the foam on the surface. By removing contaminated foam, pulp is made brighter. This step is sometimes called de-inking.
Kneading or dispersion: Mechanical action is applied to fragment contaminant particles.
Washing: Small particles are removed by passing water through the pulp.
Bleaching: If white paper is desired, bleaching uses peroxides or hydrosulfides to remove colour from the pulp.
Paper making: The clean (and/or bleached) fiber is made into a "new" paper product in the same way that virgin paper is made.
Dissolved air flotation: Process water is cleaned for reuse.
Waste disposal: The unusable material left over, mainly ink, plastics, filler and short fibers, is called sludge. The sludge is buried in a landfill, burned to create energy at the paper mill or used as a fertilizer by local farmers.

Every time paper is recycled, the fibers become shorter and weaker, so virgin pulp must be mixed with the used paper to provide strength. Because of this weakening, paper can only be recycled 4-6 times.

Even though paper fibers can only be recycled a finite number of times, it still offers many environmental and economic incentives to recycling. Virgin fibers for paper production comes from plant sources, in North America the most common source of fiber is our forests.

Recycling one tonne of newspaper saves approximately 12 trees.

In 2005, the province of Ontario recycled over 600,000 tonnes of paper products saving approximately 7.5 million trees. Not only does paper recycling save forest space, it reduces the energy required to produce paper by 40%, saves landfill space, reduces water and air pollutants by up to 74% and is cheaper to produce than paper made from virgin fibers.