At present, the waste paper used in China paper industry is divided into two categories.
One is life waste paper. There are mainly old corrugated boxes, books and magazines, old newspapers, scraps from carton factories, white paper trimming in printing houses, cement bags, mixed waste paper and miscellaneous waste paper. There is no national unified quality standard for waste paper in China, and it is being formulated at present.
The other is imported waste paper. There are mainly American waste paper, European waste paper, Japanese waste paper, and some paper mills along the coast of South China use some Hong Kong waste paper.
According to the source and characteristics of waste paper in China, it can usually be divided into the following six categories:
1. White waste paper
This kind of waste paper can also be regarded as a substitute for pulp, including unprinted white paper with relatively consistent whiteness and no harmful substances. Waste does not exceed 0.5%. This kind of waste paper can be used as bleached pulp for the production of general writing and printing paper, or for the manufacture of medium and high-grade toilet paper. This kind of waste paper is mainly white paper edge cut by printing factory.
2. Waste paper in books and magazines
This kind of waste paper mainly includes waste publications, books and so on. Not issued by a printing house or bookstore, but recycled after issuance, containing no or only a small amount of mechanical pulp. This kind of waste paper is required to contain no prohibited substances and no more than 0.25% useless substances. This kind of waste paper can produce glossy paper, writing paper, letterpress paper, toilet paper and so on after deinking to remove color and ink. It can also be used to produce suitcase cardboard or mixed with newsprint.
3. Old newsprint
It consists of bundles of selected old newspapers, excluding old magazines. Embossing and color printing parts are not higher than normal percentage. The package must contain no tar and prohibited substances, and the useless substances shall not exceed 0.25%. This kind of waste paper is mainly used to make newsprint after deinking, or to make household paper and general cultural paper.
4. Cartons and cardboard waste paper
This kind of waste paper includes kraft paper board, corrugated board trimming, old corrugated boxes, various waste paper boxes, cartons, yellow, white and gray cardboard, etc. Prohibited materials shall not exceed l%, and useless materials shall not exceed 5%. This kind of waste paper can be used to copy straw board, tea board, box board, corrugated base paper and so on. Among them, bamboo pulp and wood pulp waste paper can be used to produce linerboard.
5. Paper bag waste paper and kraft paper waste paper
This kind of waste paper refers to dried noodles such as broken cement bags and waste kraft paper bags recovered after packaging cement.
6. Mixed waste paper
This kind of waste paper belongs to low-grade waste paper, including some "garbage waste paper" (waste paper picked up from the garbage dump). It mainly includes mixed magazines, books, subpoenas, account books, exercise books for primary and secondary school students, office waste paper, waste paper after packaging items, etc. The proportion of all kinds of waste paper is not limited, the content of prohibited substances shall not exceed 2%, and the content of useless substances shall not exceed 1%. This kind of waste paper is mainly used to produce roof paperboard, moisture-proof paperboard and ordinary low-grade paperboard core layer. Mixed waste paper contains a lot of impurities, such as metal, stone, sand, belt, rags, string, plastic, hot melt adhesive, asphalt and so on.