According to the differences in raw materials, pulp can be classified into three major categories: wood pulp, non-wood pulp and waste paper pulp. Wood pulp is refined from wood through chemical, mechanical or a combination of both methods. Non-wood pulp is derived from non-wood fibers such as bamboo and grass. Waste paper pulp, on the other hand, is the recycling and reuse of paper products.
In the subfield of wood pulp, coniferous pulp and broad-leaved pulp dominate, and they are respectively derived from coniferous and broad-leaved trees. In addition, depending on different processing techniques, wood pulp can be further classified into chemical pulp, mechanical pulp and chemical-mechanical pulp. Chemical pulp separates fibers from lignin through chemical methods, such as the sulfate method and the sulfite method; Mechanical pulp includes grinding stone and wood pulp, disc grinding mechanical pulp and hot grinding mechanical pulp, etc.
