Pulp mill

A pulp mill is a manufacturing facility that converts wood chips or other plant fiber sources into a thick fiber board which can be shipped to a paper mill for further processing. Pulp can be manufactured using mechanical, semi-chemical, or fully chemical methods. The aim of pulping is to break down the bulk structure of the fiber source, be it chips, stems or other plant parts, into the constituent fibers. Chemical pulping achieves this by degrading the lignin and hemicellulose into small, water-soluble molecules that can be washed away from the cellulose fibers without depolymerizing the cellulose fibers. The earliest known methods for preparing pulp for paper making were water-powered, in 8th-century Samarkand, Abbasid Caliphate. Fibre source must be prepared before milling, which may occur in mechanical pulp mills, chemical pulp mills, or chemi-mechanical pulp mills.