Paper recycling processes can use either chemical or mechanical pulp. By mixing with water and applying mechanical action the hydrogen bonds in the paper can be broken and fibres separated again. Most recycled paper contains a proportion of virgin fibre in the interests of quality.
There are three main classifications of recycled fibre:
- Mill Broke or Internal Mill Waste:This incorporates any sub standard or grade change paper made within the paper mill which then goes back into the manufacturing system to be repulped back into paper. Such out of specification paper is not sold and is therefore often not classified as genuine reclaimed recycled fibre. However, most paper mills have been recycling their own waste fibre for many years, way before recycling become popular.
- Pre Consumer Waste: This is offcuts and processing waste, such as guillotine trims and envelope blank waste. This waste is generated out with the paper mill and could potentially go to landfill and is a genuine recycled fibre source.
- Post Consumer Waste:This is fibre from paper which has been used for its intended end use and would include office waste, magazine papers and newsprint. As the vast majority of this paper has been printed (either digitally or by more conventional means such as litho or gravure), it will either be recycled as printed paper or go through a de-inking process first.