How is paper made?

Generally, the production of printing paper is divided into two basic processes: pulping and papermaking. Pulping is to dissociate plant fiber raw materials into natural pulp or bleached pulp by mechanical method, chemical method or a combination of the two. Papermaking is to combine pulp fibers suspended in water into sheets that meet various requirements through various processes.

Paper mills generally need to store enough raw materials for 4 ~ 6 months, so that the raw materials can naturally ferment during storage, which is beneficial to pulping and ensures the continuous production of paper mills. Raw materials such as reed, wheat straw and wood are cut into pieces (used to produce chemical pulp) or wood chips (used to produce ground wood pulp) in the material preparation section, and then small pieces of raw materials are put into a digester, added with chemical liquid, and steamed with steam to make the raw materials into pulp, or the wood chips are sent to a wood mill to be ground, or they can be ground after a certain degree of cooking. Then wash the pulp with plenty of clean water, and remove coarse chips, knots, stones and sand from the pulp through screening and purification. According to the requirements of paper types, the pulp is bleached to the required whiteness with bleaching agent, and then beaten with beating equipment. Then various auxiliary materials, such as fillers, sizing agents, sizing agents, etc., are added to the pulp, and then purified and screened. Finally, the paper pulp is sent to a paper machine, the water is filtered in the wire section, squeezed and dehydrated, dried in a dryer, calendered and coiled, and then cut, rewound or cut to produce rolled paper and plain paper. If the production is to produce coated printing paper, it needs to be dried in the middle or produced into roll paper and then coated.