Pulp and black liquor prepared by grass type raw material, preparation method and use thereof

Abstract

The invention relates to unbleached pulp prepared by the ammonium sulfite cooking of a rice straw raw material and a preparation method thereof. The whiteness of the unbleached pulp is 35 to 48 percent ISO, the fracture length is between 5.0 and 7.5km, the tearability is between 200 and 275mN, and the folding times are between 30 and 100. The method comprises the steps of ammonium sulfite cookingand oxygen delignification, wherein the ammonium sulfite cooking is to cook the raw material into the pulp the harness of which has a potassium permanganate value of between 16 and 28 and is equivalent to a Kappa number of between 24 and 50. The unbleached pulp has higher strength, particularly has the fracture length and the folding times which exceed the level of hardwood pulp, can be used for manufacturing corrugated paper, lunch boxes, and packing paper which have quite high strength, or is applied to manufacturing other paper products more widely only by adding little wood pulp, greatly reduces the cost for products, and also ensures the strength of the products. The method can ensure that lignin is effectively removed and also try to reduce the degradation of fiber, thereby obtaining the unbleached pulp with good strength.

Description

technical field [0001] The invention relates to pulp and black liquor, in particular to pulp and black liquor prepared from grass raw materials, a preparation method and application thereof. Background technique [0002] At present, most of the world's pulp raw materials are wood, especially in developed countries such as the United States, Canada, Nordic countries and Russia, almost all of which are made of wood. As the demand for lumber increases year by year, the price of lumber also continues to rise. Many countries with low timber resources need to import large quantities of timber, and even countries with abundant timber resources, such as Canada, are expected to have a shortage of logs before long. Therefore, the problem of raw materials has become a major issue in the development of pulping industry in various countries, and the source of pulping raw materials is also expanding. [0003] In the pulp and paper industry, the use of grass raw materials for pulping is ...

AI Technical Summary

Problems solved by technology

3. Due to the high content of silicon and carbohydrates in the raw materials, the viscosity of the black liquor is high and the recovery is difficult

4. Grass fibers contain a large number of miscellaneous cells, which pose a series of hazards to papermaking

[0008] Heilongjiang Papermaking published an article entitled "Optimized Cooking Conditions by Straw Ammonium Sulfite Method" in No. 4, 2003, which disclosed the optimal conditions for cooking by straw ammonium sulfite method, but the quality of the pulp prepared by this cooking method not tall

[0009] In addition, the application range of paper products made from unbleached pulp with low whiteness is wider and wider, such as corrugated paper, lunch boxes, packaging paper, etc., but the strength of unbleached pulp made from straw raw materials is not very high. Requires addition of other wood-derived pulps to increase strength, thus increasing cost

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