To make pulp from wood, a chemical pulping process separates lignin from cellulose fibres. This is accomplished by dissolving lignin in a cooking liquor, so that it may be washed from the cellulose; this preserves the length of the cellulose fibres. Paper made from chemical pulps are also known as wood-free papers–not to be confused with tree-free paper; this is because they do not contain lignin, which deteriorates over time. The pulp can also be bleached to produce white paper, but this consumes 5% of the fibres; chemical pulping processes are not used to make paper made from cotton, which is already 90% cellulose.
To make pulp from wood , a chemical pulping process separates lignin from cellulose fibres . This is accomplished by dissolving lignin in a cooking liquor , so that it may be washed from the cellulose ; this preserves the length of the cellulose fibres . Paper made from chemical pulps are also known as wood - free papers – not to be confused with tree - free paper ; this is because they do not contain lignin , which deteriorates over time . The pulp can also be bleached to produce white paper , but this consumes 5 % of the fibres ; chemical pulping processes are not used to make paper made from cotton , which is already 90 % cellulose .
What percentage of fibres are wasted in the bleaching process?
What percentage of fibres are wasted in the bleaching process ?
5%
5%