Production technology of white top liner

Abstract

The invention relates to a production technology of a white top liner. The technology comprises the following steps that 1, ONP pulp is prepared, water is added to fibers obtained from first flotation of the ONP pulp, bleaching is conducted, first ONP pulp is obtained, water is added to fibers obtained from second flotation of the ONP pulp, bleaching is conducted, second ONP pulp is obtained, concentration is conducted on ONP pulp of two times of flotation, and third ONP pulp is conducted; 2, DMOW pulp is conducted, water is added to fibers obtained from first flotation of the DMOW pulp, bleaching is conducted, first DMOW pulp is obtained, water is added to fibers obtained from second flotation of the DMOW pulp, bleaching is conducted, second DMOW pulp is obtained, concentration is conducted on DMOW pulp of two times of flotation, and third DMOW pulp is conducted; 3, the first DMOW pulp, the first ONP pulp and original wood pulp are mixed, a surface layer is obtained after the mixture flows to paper-making meshes, the second DMOW pulp and the second ONP pulp are mixed, a bottom layer is obtained after the mixture flows to the paper-making meshes, the third DMOW pulp, the third ONP pulp and OCC pulp are mixed, and a core layer is obtained after the mixture flows to the paper-making meshes.

Description

technical field [0001] The invention relates to a papermaking process, in particular to a production process for white-faced kraft cardboard. Background technique [0002] Due to the intensified competition of domestic products and the increase of imported products, paper mills in North America hope to improve the competitiveness of their products by improving the brightness, whiteness and opacity of white-top kraft linerboard. In the United States, white kraft liner tends to be high whiteness. Mainstream premium graphic paper producers are interested in improving the brightness and whiteness of their papers, with white top kraft linerboard for imaging, commercial printing, envelopes and forms being the focus. [0003] At present, in order to improve the whiteness of the domestically produced white-faced linerboard, the pulp is generally bleached and chemical additives such as optical brighteners and white fillers are added to the wet end and the surface. As the country is...

AI Technical Summary

Problems solved by technology

At present, my country adopts the CHE bleaching process for pulp bleaching. During the bleaching process, more than 40 kinds of organic chlorides will be produced, which will seriously pollute the environment. Therefore, it is the development direction to replace the existing bleaching technology with chlorine-free ECF bleaching.

[0004] However, with the implementation of chlorine-free bleaching technology, the whiteness of the pulp cannot be improved, the quality of the pulp is limited, and the cost is high. At the same time, because the white-faced kraft cardboard uses DMOW pulp to bleach the vermicelli, there are more ink and sticky molecules in the pulp, resulting in The product has low whiteness, high dustiness, low strength and low product competitiveness