recycling our newspapers and office paper. In fact, so many of us recycle our paper products that worldwide, an estimated 200 million tons of paper and cardboard are produced annually from recycled paper sources¹. That’s a lot of recovered paper that can be made into new products, like paper bags, cardboard boxes, and notebooks!
You know that recycling your paper is important, but have you ever wondered how it gets turned into something new?
The paper recycling process
- The paper that you put into your recycling bin is collected by your recycling company and is then added to paper products collected from other sources at the recycling facility.
It is very important to check with your recycling company to determine which types of paper products can be recycled and which ones cannot. For instance, used paper towels and paper plates cannot be recycled because they contain food particles. However, in most cases, such paper products can be composted in your backyard or composted by your local waste management company or municipality².
- At the recycling facility, the paper is separated by type and grade, and then it is wrapped into bundles and sent to paper mills for further processing.
- The first step of processing the paper is to place the paper inside a big vat called a “pulper,” where it is chopped into pieces and then water is added. The mixture is then heated to further break down the paper fibers.
- During the screening process, the pulp is put through screens to remove items such as plastic tape.
- The pulp is cleaned. Larger pulp fibers are separated into smaller fibers, and any remaining bulk materials such as staples and paper clips are removed.
- Deinking removes printing ink and sticky materials such as glue residue and adhesives, and involves the following two processes:
- “Washing” removes small particles of ink by rinsing the pulp with water.
- “Flotation” removes larger particles and sticky materials by using air bubbles. During flotation, surfactants are added to the pulp that force the remaining ink and sticky materials to the top and allow for easier removal from the clean pulp.
- Next, the pulp is refined, color-stripped, and bleached.
During the refining process, the pulp is beaten, swells, and larger fiber bundles are separated into individual fibers.
If the paper pulp contains any dyes, color-stripping chemicals are added to remove them.
If white paper is desired, the paper pulp may be bleached with hydrogen peroxide, chlorine dioxide, or oxygen to make it white and to brighten it.
Brown paper pulp, such as paper pulp used to make paper towels, is not bleached.
- The pulp is made into new paper. The pulp can be used alone or additional virgin wood fiber can be added to the pulp to give the paper extra strength or smoothness.
- The watery pulp is sprayed onto quickly moving screens, where water drains and the recycled fibers bond together into sheets.
- Press rollers squeeze more water out of the sheets and heated metal rollers dry the paper sheets.
- If coated paper is desired for smooth printing, a coating mixture may be applied to the paper near the end of the paper-making process or after the process is completed.
Unfortunately, there is a limit to how much recovered paper can be recycled. During the paper recycling process, the individual paper fibers are shortened more and more each time they are recycled, and generally have a maximum limit of 5-7 times that they can be recycled³. Such “end of the line” paper products include things like cardboard egg cartons that can no longer be recycled. The best way to dispose of these products in an environmentally-friendly way is to compost them at home or in a municipal or commercial facility.