High-whiteness coated ivory board and preparation method thereof

Abstract

The invention relates to the field of papermaking, and discloses a high-whiteness coated ivory board and a preparation method thereof. The high-whiteness coated ivory board comprises raw paper and a coating layer covering the surface of the raw paper, wherein the raw paper comprises a surface paper layer, a core paper layer and a bottom paper layer, the coating layer comprises a pre-coating layer, a surface coating layer and a back coating layer, the paper pulp of the raw paper comprises 80-90 parts of hardwood pulp and 10-20 parts of softwood pulp, the paper pulp is formed by bleaching treatment through a biological enzyme method, the coating materials of the pre-coating layer, each of the surface coating layer and the back coating layer comprises a pigment, a coating adhesive and a coating additive, the pigment comprises 85-95 parts of ground calcium carbonate and 5-15 parts of kaolin, and the coating additive comprises a fluorescent whitening agent accounting for 0.05-0.10% of the total weight of the coating materials. The preparation method comprises the steps of paper pulp preparation, net loading, squeezing and water removal, preliminary drying, on-line coating in a machine, drying and subsequent calendaring, reeling, cutting and packaging. The invention provides a method for preparing the high-whiteness coated ivory board by using a biological enzyme method for bleaching and using a small amount of a whitening agent, and the whiteness of the prepared coated ivory board is 94% or above.

Description

technical field [0001] The invention relates to the technical field of papermaking, in particular to a high-whiteness coated white cardboard and a preparation method thereof. Background technique [0002] Coated white cardboard includes a base paper and a coating layer. The base paper usually includes a face paper layer, a core paper layer and a bottom paper layer. The coating layer is uniformly coated on one or both sides of the base paper to form a coating layer, which is calendered and dried. , Finishing and other processes can be prepared coated white cardboard. Coated white cardboard is mainly used for printing art prints, packaging cartons for high-end goods, etc. [0003] Whiteness (commonly referred to as brightness in the world) is a visual effect of human beings on paper. Outstanding whiteness can give people a conspicuous feeling, and it can also show the contrast of printing and the vividness of color. It is also loved by customers. Therefore, Whiteness is an i...

AI Technical Summary

Problems solved by technology

[0004] Bleaching is the process of obtaining high-whiteness pulp by removing lignin. Currently, paper mills use the sulfate method for bleaching. The amount of wastewater discharged in this process accounts for more than 50% of the total wastewater, and due to the bleaching agent and pulp The reaction will produce a large amount of pollutants, even carcinogens, especially in the bleaching wastewater produced in the production process using elemental chlorine bleach as the main bleaching chemical, which will contain more AOX. AOX contains a di The toxicity of oxins is equivalent to more than 1000 times that of potassium cyanide (KCN). Therefore, the bleaching wastewater using the sulfate method is difficult to treat, has high toxicity to the human body, and increases environmental pollution. Therefore, a new bleaching method is needed It is used to treat pulp; and fluorescent whitening agent has carcinogenic effect and is expensive. On the one hand, its use will increase production costs, and on the other hand, its accumulation to a certain dose will endanger human health, so it is necessary to reduce its usage

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