A kind of bleaching process of bamboo dissolving pulp

Abstract

The invention relates to the technical field of paper-making pulping and particularly relates to a bleaching process of bamboo dissoluble pulp. The process comprises the processing steps: two-section delignification bleaching, first-time washing, chlorine dioxide bleaching under strong acid condition, addition of a bleaching accelerant, extraction by hydrogen peroxide, oxygen and intensified alkaline, third-time washing, chlorine dioxide bleaching, fourth-time washing and enzyme treatment. Compared with the prior art, the bleaching process has the advantages that through pentosan treatment, the fiber hydrolysis degree of pulp and the whiteness of a pulp board can be greatly improved, the using amount of bleaching agents such as chlorine dioxide and hydrogen peroxide can be reduced, the production process is greatly simplified, and the saving of the cost is facilitated.

Description

technical field [0001] The invention relates to the technical field of papermaking and pulping, in particular to a bleaching process of bamboo dissolving pulp. Background technique [0002] Dissolving pulp is widely used in textile viscose fiber, nitrocellulose, cellulose acetate and other cellulose derivative industries, and the market demand is huge. At present, the newly developed bamboo dissolving pulp has a broad market prospect and can fill the gap of dissolving pulp in my country. However, in the process of paper pulping, the production equipment and technology of bamboo dissolving pulp are relatively backward. In the prior art, the bleaching process of bamboo dissolving pulp mainly adopts the traditional chlorine-containing C~E~H (C~chlorine gas, E~alkali extraction, H~hypochlorite) three-stage bleaching process. The process has the following defects: 1) The three-stage bleaching process consumes a large amount of bleaching agents (mainly chlorine dioxide, hydrogen...

AI Technical Summary

Problems solved by technology

However, in the process of paper pulping, the production equipment and technology of bamboo dissolving pulp are relatively backward

In the prior art, the bleaching process of bamboo dissolving pulp mainly adopts the traditional chlorine-containing C~E~H (C~chlorine gas, E~alkali extraction, H~hypochlorite) three-stage bleaching process. The process has the following defects: 1) The three-stage bleaching process consumes a large amount of bleaching agents (mainly chlorine dioxide, hydrogen peroxide and other chemical reagents), which not only makes the raw material cost of the bleaching agent high, but also produces a large amount of wastewater pollution. The cost increases accordingly, resulting in high production cost and low production capacity of pulping; 2) In the wastewater using a large amount of bleaching agents, especially chlorine and hypochlorite will produce such as chloroform, dioxin, etc. during the bleaching process There are more than 40 kinds of organic chlorides (AOX). These toxic substances are not only carcinogenic, teratogenic, highly toxic and difficult to handle, but also pose a serious threat to the ecological environment and human health; 3) The water filtration performance of the slurry is poor, resulting in The water content of the pulp sheet is relatively high, which cannot meet the requirements; 4) The traditional three-stage bleaching still cannot meet the demand for products with high whiteness requirements, and it is prone to yellowing; 5) In order to improve the purity of the pulp, the traditional process uses The cellulose degradation in the pulp usually requires a pre-hydrolysis process before bleaching, resulting in complex processes, high energy consumption, and low cellulose degradation rate, resulting in low purity of the final pulp

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