The straw ammonium sulfite pulp is completely free from chlorine-based bleaching agents
Due to their small size, these impurity cells can be easily removed during washing and screening; however, some rod-shaped impurity cells and their aggregates remain, thereby increasing the pulp yield. Rice straw pulp contains abundant fine yellow dust particles, which are difficult to cook in the cooking process and form fibrous bundles within the pulp, constituting the primary source of fibrous yellow dust. A notable characteristic of rice straw is its high ash content, reaching as high as 17.54%.
1.2 Ammonium sulfite pulping from straw
Ammonium sulfamate pulping is the abbreviated term for pulp production using neutral ammonium sulfite. In the early 1970s, to address the environmental pollution associated with alkali-based and sulfate-based pulping methods, the paper industry widely adopted this technology domestically, utilizing raw materials such as rice straw, sugarcane residue, cotton stalks, reeds, and red hemp to produce pulp for printing, writing, packaging paper, and cardboard production.
