1. What are the raw materials for modern papermaking? A […]
1. What are the raw materials for modern papermaking?
A: The raw materials for modern papermaking include plant fibers (wood, bamboo, grass, etc.), mineral fibers (asbestos, glass filaments, etc.), other fibers (nylon, metal wire, etc.), as well as polymer materials obtained by cracking petroleum. The paper currently used for writing, printing and packaging is still mainly made of plant fiber as the main raw material.
2. What are the types of paper fiber plant materials?
A: At present, plant fiber raw materials for the paper industry can be mainly divided into two categories:
Wood fiber raw material: plant fiber obtained directly from trees.
Non-wood fiber raw materials: It is divided into grass fiber raw materials, bast fiber materials and seed wool fiber materials.
3. What is the composition and role of paper commonly used accessories?
A: Excipients are various additives that are added to the paper to meet the different performance properties of the paper. Excipients are composed of fillers, rubber compounds, colorants and other chemical additives.
The filler can improve the smoothness and opacity of the paper; the rubber can make the paper water resistant; the color can increase the whiteness of the paper; the dye can color the paper; other chemical additives can change the properties of the paper to provide Some special uses of paper.
4. What is the role of the rubber compound?
A: Paper made from plant fibers has a large number of capillary pores between the fibers themselves and the fibers, and the cellulose and hemicellulose constituting the fibers contain a large amount of hydrophilic hydroxyl groups, so they can absorb water or other liquids. In order to prevent the paper from being infiltrated by water or other liquids, it is necessary to add a liquid-repellent colloidal substance or a film-forming substance, that is, a rubber compound, to the paper to impart resistance to liquid penetration and diffusion. The process of applying a compound in the paper industry is called sizing.