METHOD OF MANUFACTURING PAPER RESISTANT TO MOISTURE AND POLLUTION, AND PAPER RESISTANT TO MOISTURE AND POLLUTION Russian patent published in 2019 - IPC D21H21/16 D21H19/10 

FIELD: pulp and paper industry.

SUBSTANCE: invention relates to the pulp and paper industry, in particular to the production of paper, which contains security features, and can be used for the manufacture of banknotes and valuable documents that require an increased time spent in circulation. Method of making paper involves treating a porous paper web on both sides with a composition based on an aqueous dispersion of polymers, imparting resistance to moisture and contamination to the paper, removing excess aqueous dispersion from the porous paper web and drying. Porous paper web consists mainly of cotton fibers with a milling degree between 50 and 70 degrees of Schopper-Riegler. During the paper web casting process, the specific pressure on the presses in the wet press section of the paper machine is adjusted so that the air permeability of the paper prior to processing ranges from 100 ml to 170 ml per minute.

EFFECT: there is an increase in the absorption of the composition in paper in terms of absolutely dry matter, as well as an increase in the resistance of paper to wear while maintaining good resistance to moisture and pollution.

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