According to textual research, the production of paper began in the Western Han Dynasty, and it was widely circulated in the Wei, Jin, Southern and Northern Dynasties. Because of its wide use, papermaking has been further improved. Paper raw materials are also diversified. There are many kinds of paper, such as bamboo curtain paper, rattan paper, fish egg paper, etc ... Cai Lun has a wide range of papermaking raw materials. Paper made of rotten fishing nets is called net paper, and paper made of rags is called cloth paper.
During the Sui and Tang Dynasties, the famous Xuan paper was born. There is a legend in Xuanzhou, Anhui Province, the main producing area of Xuan paper: Cai Lun's apprentice Kong Dan, who made paper in southern Anhui, always wanted to make a particularly ideal white paper for his master to paint and compose. But after many experiments, it can't be realized. Once, he happened to see some sandalwood trees lying beside the mountain stream, which had been corroded by water for a long time and had rotted and turned white. Later, he made paper with this bark and finally succeeded. It can be concluded that using bark as rice paper has been very popular in the Tang Dynasty. )
On the basis of the previous generation of yellow paper dyed in the Tang Dynasty, wax was evenly coated on the paper to make the paper have the advantages of luster, luster and beauty, which is called hard yellow paper. The paper industry of the Five Dynasties continued to develop. Zhangzhou's Chengxin Tang paper was always considered as the best paper until the Northern Song Dynasty. During the Ming and Qing Dynasties, the paper industry flourished and innovated constantly. All kinds of stationery are popular again, and white paper and elegant paper are highly respected in texture, with bright and quiet colors, such as pastel paper and printing and dyeing paper in Kanggan period. By the Qing Dynasty, the production of paper had reached a perfect level. The process of making paper)
The production of general 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, filtered for moisture 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.