A kind of preparation method of offset paper or electrostatic copy paper

Abstract

The invention relates to a preparation method of offset paper or electrostatic copy paper. The method belongs to the field of pulp and paper making. The method uses chemical pulping without sulfur compounds. The obtained chemical pulp is mixed with other pulp and additives are added to prepare paper. The paper is surface-sized to obtain finished paper, and the finished paper is friendly to human eyesight. During the implementation of the present invention, no environmentally harmful chemical raw materials such as sulfides and chlorine-containing compounds are used, and no highly harmful bleaching wastewater is produced. The present invention saves investment and operating costs, and reduces the amount of fresh water used for preparation. The method of the present invention is environmentally friendly. Friendly and strong.

Description

technical field [0001] The invention relates to a preparation method of offset paper or electrostatic copy paper, in particular to a preparation method of natural color offset paper or natural color electrostatic copy paper, which belongs to the field of pulp and papermaking. Background technique [0002] As we all know, the pulp and paper industry is a high water consumption and high pollution industry. Especially in the chemical pulping process of wood or bamboo, kraft pulping is used. A large amount of sodium sulfide is used in the kraft pulping process. During the preparation process, a considerable part of sodium sulfide will be reacted to produce volatile hydrogen sulfide. or sulfur dioxide and other sulfide gases, which diffuse into the atmosphere and undergo a series of chemical reactions, and eventually drop to surface water in the form of acid rain, causing serious cumulative pollution to the environment; at the same time, hydrogen sulfide or sulfur dioxide and oth...

AI Technical Summary

Problems solved by technology

In order to achieve higher whiteness, preparation companies usually use chlorine-containing compounds without exception, such as chlorine gas, chlorine dioxide, hypochlorite, etc. The use of a large number of chlorine-containing compounds leads to carcinogenic and teratogenic Highly toxic substances such as dioxin and other AOX substances, which are seriously harmful to water bodies, and the hazards are not easy to be eliminated by natural biochemical degradation; although few enterprises have adopted the completely chlorine-free bleaching process, their The process still needs to use bleaching agents, such as hydrogen peroxide or oxygen, etc., and corresponding preparation equipment is required, that is, the bleaching section of the enterprise requires a large investment in hardware

Usually adding a bleaching section will lead to an increase of more than 30% of enterprise investment; in addition, adding a bleaching section will increase the preparation operation and management costs while reducing the added value of the product

However, during the bleaching process, a large amount of preparation sewage that is not easy to be treated biochemically is produced, especially the preparation sewage formed by the bleaching process using chlorine element bleaching agent is extremely difficult to treat.

Usually, the preparation pollution in the bleaching section accounts for 30% of the entire preparation sewage, and this kind of preparation sewage cannot be recycled or cannot be fully recycled

Generally speaking, the pulp yield will decrease by 2-4% after bleaching, which reduces the utilization rate of raw materials and increases pollution, thus reducing the added value of the product.

According to research reports by scientists, white paper has serious damage to the eyes of the human body, especially teenagers, especially when reading at night or under strong light. White paper will cause irreversible harm to the eyes, that is, high whiteness paper is not good for human health.