METHOD FOR INCREASING DIMENSIONAL STABILITY OF A PAPER OR CARDBOARD PRODUCT Russian patent published in 2021 - IPC D21H17/52 D21H17/55 D21H17/57 D21H17/62 D21H21/16 D21H21/18 D21H21/20 

FIELD: paper; cardboard product manufacturing.

SUBSTANCE: present invention relates to a method for manufacturing a paper or cardboard product having increased dimensional stability. The method includes obtaining pulp containing fibers that have never been dried, processing the pulp with a strengthening composition, and forming a paper or cardboard product from the processed pulp. The strengthening composition contains a resin component that provides a constant moisture resistance, and a sizing agent. The resin component is selected from polyamidoamine-epigalohydrin (PAE) resins, polydiisocyanate resins, urea-formaldehyde (UF) resins, melamine-formaldehyde (MF) resins, polydiisocyanate (DI) resins and mixtures thereof. The sizing agent is selected from an alkylene ketene dimer (AKD), an alkyl succinic anhydride (ASA), a rosin derivative, or a mixture thereof. Moreover, the amount of fibers that have never been dried in the pulp is at least 15 wt % based on the total dry weight of the pulp.

EFFECT: invention provides increased moisture resistance, decreased moisture expansion and increased hydrophobicity of a paper or cardboard product.

18 cl, 5 tbl, 1 ex