PAPER AND CARDBOARD PRODUCTS Russian patent published in 2021 - IPC D21H11/18 D21H19/52 D21H11/14 

FIELD: paper processing.

SUBSTANCE: group of inventions relates to products such as paper and cardboard products containing a substrate containing cellulose and a cover layer containing microfibrillated cellulose and inorganic solids, as well as to methods for producing such paper and cardboard products and the corresponding use of these paper and cardboard products. Microfibrillated cellulose and inorganic material in the form of particles (consisting of solid particles) are applied at the stage when the wet substrate is in the process of forming on the wire mesh of a paper machine, which thereby avoids additional costs for larger-scale equipment and machinery, as well as for separate drying of the coating. Microfibrillated cellulose facilitates the application of inorganic solid particles to the surface of a wet paper or cardboard substrate, when applied in this way, by trapping inorganic solid particles on the surface of the substrate and by giving the composite material sufficient strength and a suitable porous structure, which makes it suitable for printing and other end uses.

EFFECT: extension of the range of solutions to improve paper quality.

34 cl, 7 dwg, 3 tbl, 4 ex