Introduction
Mechanical wood pulp is ground into fibers in direct mechanical approach, it does not need chemicals, and does not remove non-cellulose ingredients in wood, therefore No pollution, high yield, simple process and other advantages. In the case of increasing pollution control, these advantages of mechanical wood pulp are more important.
Development history
The production of mechanical wood pulp is started from the middle of the nineteenth century, and the molar molter began in 1885 to produce printed paper, even though it was only The applet is 25%, the rest of the shining, but soon, people find that the printing performance of paper is improved as the molar ratio increases.
Compared to chemical plasma, the fine fiber content of the grinding wood pulp is high, the fibers are short and hard, which helps improve the shampoo, improve loose thickness, smoothness, ink absorption and not Transparency, but its strength is low, so the proportion of newspapers is limited to 70-80%, and the remaining 20-30% require long fibroblasts.
Many local wood resources are insufficient, so wood prices have risen, which encourages people to use wood waste, sawdust and wood-producing machinery pulp; pollution caused by chemical plasma, also require development of new pulping methods.
In terms of news paper production, mechanical wood pulp strikes from two aspects to replace expensive chemical smelters: First, it is used to use a high-rate gel with grinding wood pulp; the other is to develop high rate Mechanical pulp makes it have the advantage of grinding wood pulp and chemical seizing so that news paper can be produced without using chemical seizing or grinding wood pulp. Many paper mills have used a variety of ratios when they develop in this goal, but most news paper mills are using grinding wood pulp or wood, grinding wood pulp, plus small amount of chemical gear production, and a few factories use 100 % Wood chip grinding wood pulp production.
Wooden slice is developed in the 1930s with the development of the coil mill, originally used to handle rough slabs for grinding wood pulp to improve the quality level of the entire grinding wood pulp, then After the grinding wood pulp is applied. In the 1950s, the wood film directly produced mechanical wood pulp (RMP) was recognized as a new pulping method.
Advantages and Disadvantages
It has a low production cost, simple production process, strong ink ink ink, high opacity, and smooth paper. Suitable for printing requirements. However, due to the short fiber, the non-cellulose component content is high, so the paper strength is low. In addition, due to the vast wood in wood, most of the non-cellulose is not removed, the paper produced is easy to become brittle, and it cannot be stored for a long time. In general, the quality of mechanical wood pulp (RMP) is not better than the grinding wood pulp (SGW), its strength is high, but the optical performance is not as good as SGW, and because there are more crude fibers, the paper surface is rough, affecting the quality of printing.
Type
Mechanical wood paste usually refers to white mechanical wood pulp and brown mechanical wood pulp. White mechanical wood pulp is mainly used to produce news paper, or it can be equipped with other pulp writing paper and printed paper; brown mechanical wood paste is used to produce wrapping paper and cardboard, especially industrial cardboard.