1. MECHANICAL WOOD PUL

Mechanical wood pulp, also called grinding wood pulp, is a pulp made by mechanical method of grinding fiber raw materials. It plays an important role in paper industry. It has low production cost, simple production process and strong ink absorption of paper. Opacity is high, paper is soft and smooth. Pulp products are suitable for printing. But because of the short fiber, the content of non-cellulose components is high. so that the paper strength is low. Besides because most of the lignin and other non-cellulose in the wood have not been removed, the paper produced by mechical wood pulp is easy to be yellow and brittle and can not be preserved for a long time. 

Mechanical wood pulp usually refers to white mechanical wood pulp and brown mechanical wood pulp . White mechanical wood pulp is mainly used to produce newsprint , it can also be added to other pulp and used to manufature writing paper and printing paper ; Brown mechanical wood pulp is mostly used for the production of wrapping paper and cardboard, especially for industrial cardboard. 

 2. SULPHATE WOOD PULP

Sulphate wood pulp is use of sodium hydroxide and sodium sulphide mixture as a cooking agent. In the cooking process, because the role of liquid medicine more moderate, the fiber is not strongly eroded,   so strong and powerful.  The paper made of it has excellent folding, burst and tear resistance. It can be divided into bleached and unbleached. 
Unbleached sulphate  wood pulp is available for the manufacture of kraft paper, sack paper, kraft linerboard, general wrapping paper and cardboard, etc. Bleached Kraft pulp can be used to produce advanced printing paper, drawing paper, offset paper and writing paper, etc. 

 3. SULPHITE WOOD PULP

Sulphite wood pulp is a mixture of sulfurous acid and acid sulfite as cooking agent. The pulp fibers are long, soft,  good toughness, high strength, easy to bleach, and have excellent interlacing ability. According to its refining degree, it can be divided into three kinds: unbleached, semi-bleached and bleached. 

Unbleached pulp due to containing a small amount of lignin and colored impurities, so  yellow, the fiber is also harder, and more for manufacturing  medium printing paper, thin wrapping paper and translucent paper and oil-proof paper.

Semi-bleached pulp contains a lot of pentosan, thus manufacturing transparent tracing paper and parchment. 

Fiber of bleached pulp white, pure and soft texture, but due to bleach treatment, the fiber strength is lower than the unbleached pulp. This kind of pulp is used for making all kinds of advanced paper.

 4. WASTE PAPER PULP

Waste paper pulp by using waste paper or the paper edges cut  by the machine of printing plant as raw material , made by mechanical stirring and bleaching or deinking. 

The fiber strength and properties of waste paper pulp. It is determined by the type of pulp used in waste paper. But  the fiber is inferior to the original one because the fiber is again attacked by the chemical solution or damaged by mechanical force. According to the quality of waste paper pulp, it is used to make printing paper, writing paper, paperboard and lower grade paper respectively. 

In addition to the above described several kinds of pulp, there are straw pulp, reed pulp, bagasse pulp, bamboo pulp, cotton pulp, hemp pulp and synthetic pulp, etc.