IMPROVED FILTER PAPER Russian patent published in 2022 - IPC D21H27/08 D21H13/14 D21H13/24 D21H13/26 D21H15/10 D21H17/67 

FIELD: filtration.

SUBSTANCE: invention relates to filter paper for the manufacture of aqueous extracts and a method for its production, and to a package made of this paper. Filter paper contains long-fiber cellulose, which has following properties: specific weight of more than 9.0 g/m² and less than 13.5 g/m², density of more than 280 kg/m³ and less than 350 kg/m³, thickness of at least 38 mcm and at most 48 mcm, roughness of more than 700 ml/min and less than 1300 ml/min, resistance to bending in the longitudinal direction of paper of more than 50 mN and less than 75 mN, and air permeability of more than 17,000 cm/(min · kPa) and less than 26,000 cm/(mi· kPa). In this case, filter paper is either free of abaca and sisal fibers, or, if abaca and/or sisal fibers are present, together they make up less than 20% of the paper weight. The method includes following stages: suspending long-fiber cellulose in water and grinding at least long-fiber cellulose in a grinder, feeding a suspension that contains at least ground long-fiber cellulose onto a paper machine mesh, dehydrating the suspension through the paper machine mesh to form paper, and pressing paper by applying sufficient pressure to obtain the specified filter paper.

EFFECT: providing filter paper suitable for the manufacture of aqueous extracts, in particular, infused beverages such as tea or coffee, which contains significantly less or does not contain abaca or sisal fibers, while filter paper should have the same functional capabilities in the manufacture of aqueous extract as conventional filter paper.

30 cl, 2 tbl