Abstract: An additive for paper or board production e.g. for decreasing pitch problems. The additive includes at least a component including fatty acid glycerides, preferably triglycerides, comprising a high percentage of unsaturated, preferably polyunsaturated, fatty acids. Raw or partly polymerized plant oil, such as sunflower oil, may be used.

Abstract: An additive for paper or board production e.g. for decreasing pitch problems. The additive includes at least a component including fatty acid glycerides, preferably triglycerides, comprising a high percentage of unsaturated, preferably polyunsaturated, fatty acids. Raw or partly polymerized plant oil, such as sunflower oil, may be used.

Abstract: Method for the impregnation of water-repellent paper by using an ammonium salt of a substituted succinic acid amide as the moistening agent. The water-repellent properties of a paper impregnated in accordance with the method are restored after drying.

Abstract: A paper material has been invented that contains cellulose substituted by means of N-methylol compounds. As N-methylol compounds may be used, e.g., reaction products of urea, glyoxal, and formaldehyde, methylolated melamines, and N-methylol-acrylamide copolymers. The paper is manufactured best by impregnating paper with an aqueous solution or dispersion of a N-methylol compound and by drying it at 130.degree. to 200.degree. C. in order to produce condensation. Papers in accordance with the invention have good properties of strength against decomposition and wet strength, which properties can be adjusted readily by varying the degree of substitution or cross-linking of the cellulose. The papers are particularly well suitable, e.g., for the manufacture of plant-growing pots and corrugated fibreboard.