Solvent-resistant liquid packaging board, its manufacturing method and use, and a drinking cup made of the same

摘要

Polymer-coated, heat-sealable liquid packaging board that resists solvents (e.g. strong alcoholic drinks), method of manufacturing board, and drinking cup made of board. Resistance to solvents is achieved by lowering raw edge penetration into the board. The fiber base of the board contains at least 1.3 kg of hydrophobic size containing alkyl ketene dimer and at least 1.0 kg of wet-strength size per 1 ton of dry matter. Fiber base density is 630-800 kg/m3. The amount of heat-sealable polymer in the top layer is higher than the Bristow wheel roughness volume of the uncoated fiber base and/or at least 14 g/m2. When manufacturing the board, the alkyl ketene dimer size and a wet-strength size are added into the stock. The pH of the tail water is adjusted so as to be alkaline (about 7 or more).

主权项

1. A heat-sealable liquid packaging fibre-based board that resists solvents selected from the group consisting of alcoholic drinks, organic solvents, and liquid soaps, which on at least one side is provided with a polymeric coating layer having a weight of at least 15 g/m2, characterized in that, to lower the raw edge penetration to the board,
the fibre base comprises at least 1.3 kg of hydrophobic size containing alkyl ketene dimer (AKD) per 1 tonne of dry matter and at least 1.0 kg of wet-strength size per 1 tonne of dry matter, that the density of the fibre base is 630-800 kg/m3, that the amount of heat-sealable polymer in the coating layer is higher than the Bristow wheel roughness volume of the uncoated fibre base and/or at least 14 g/m2, that the fibre base has been manufactured by a board machine by adjusting the pH of the tail water to a value of over 9.0, that the pH of the water extract of the board, which is measured by the ISO 6588 method, is over 7.0, and that the raw edge penetration of a 2 weight-% soap solution at 23° C. for 1 hour is 2.5 millimeters or less.