The Process

After being sorted from other materials, paper is sorted into grades. Different grades have different uses, with higher grades for office paper and lower grades for things like newspaper. They are then stored until needed by a mill. Once at the mill, it gets pulped; it is shredded into small pieces and mixed with water and chemicals to break it down into fibers. Then, it gets run through a screen to remove any remaining contaminants and spun in a conical cylinder to clean it, and it is then sprayed onto a conveyor belt. It will also be de-inked at this stage if necessary. Finally, heated metal rollers dry the paper and press it into a sheet than is then rolled up and ready to be used for paper products.

Paper Grades

The grade of paper is determined by its fiber length. Each time it is recycled, the fibers shorten, and it gets lower in grade. After five to seven times being recycled, fibers become too short to make new paper. At this stage, they must be mixed with virgin fibers to be able to be re-used. There are five basic grades for paper: old corrugated containers, mixed paper, old newspapers, high grade deinked paper, and pulp substitutes. These names are mostly self-explanatory: old corrugated cardboard is typically used in packaging and known more commonly as ‘corrugated cardboard,’ mixed paper is a broad category that includes mail and magazines, old newspapers are recycled newsprint, and high grade deinked paper is copy paper or envelopes that has had the ink removed. Pulp substitutes are rarer and are typically discarded scraps from mills.

Source: Earth 911