Production of paper and cardboard

Abstract

Paper and cardboard are produced by draining a paper stock by a method in which a stock having a consistency of from 2.5 to 5% by weight is used as a starting material, and (a) from 0.1 to 2% by weight of an activated bentonite are added and the stock consistency is then brought to 0.3-2% by weight by dilution with water, after which (b) from 0.01 to 0.1% by weight of a cationic polyelectrolyte having a charge density of not less than 4 meq/g of polyelectrolyte is added and distributed therein, and, after thorough mixing (c) from 0.003 to 0.3% by weight of a high molecular weight polymer based on acrylamide or methacrylamide is metered in and mixed with the paper stock, the percentages in each case being based on dry paper stock, and the resulting pulp is drained on a wire. The paper obtained is distinguished in particular by good printing properties in the offset printing process.

Dependencies are inferred from the claim text.