1. Mechanical wood pulp (MECHANICALWOOD-PULP) Mechanical wood pulp, also known as ground wood pulp, is pulp made by mechanically grinding fiber raw materials. It occupies an important position in the paper industry. Its production cost is low, the production process is simple, the finished paper has strong ink absorption, high opacity, and the paper is soft and smooth. Suitable for printing requirements. However, due to the short fiber and high content of non-cellulose components, the paper strength is low. In addition, because most of the lignin and other non-cellulose in the wood have not been removed, the paper produced with it is easy to turn yellow and brittle, and cannot be stored for a long time. Mechanical wood pulp usually refers to two kinds of white mechanical wood pulp and brown mechanical wood pulp. White mechanical wood pulp is mainly used to produce newsprint, and it can also be mixed with other pulps to make writing paper and printing paper; brown mechanical wood pulp is mostly used to produce packaging paper and cardboard, especially industrial cardboard.
2. SULPHATEWOODPULP SULPHATEWOODPULP uses a mixture of sodium hydroxide and sodium sulfide as the cooking agent. During the cooking process, because the action of the liquid medicine is relatively gentle, the fibers are not strongly corroded, so it is strong and strong, and the made paper has good flexural, tear-resistant and tear-resistant strength. It can generally be divided into two types: bleached and unbleached. Unbleached sulphate wood pulp can be used to manufacture kraft paper, paper bag paper, kraft cardboard paper and general packaging paper and cardboard. Bleached sulphate wood pulp can be used to make printing paper, painting newspaper, offset paper and writing paper.
3. SULPHITEWOODPULP (SULPHITEWOODPULP) Sulphite wood pulp is a mixture of sulfurous acid and acid sulfite as cooking agent. The pulp has long fibers, soft properties, good toughness, high strength, easy bleaching, and good interweaving ability. According to its degree of refining, it can be divided into three types: unbleached, semi-bleached and bleached. Unbleached pulp contains a small amount of lignin and colored impurities, so it is yellow and the fiber is hard. It is mostly used to make medium printing paper, thin packaging paper, translucent paper and greaseproof paper. Semi-bleached pulp contains a lot of polypentose, so transparent tracing paper and imitation parchment paper are copied. The fiber of bleached pulp is white, pure and soft, but due to bleaching treatment, the fiber strength is lower than that of unbleached pulp. This kind of pulp is mostly used to make all kinds of paper.
