Patent ID: 6440489
Filing Date: 2002-08-27
Classification: B01D,D21H,F24F

Abstract:
A method of producing a bacteriostatic moisture exchange element comprising the steps of:a) providing a piece of paper; b) immersing the paper in a concentrated waterglass solution at a temperature in the range of 45-95Â° C., wherein said concentrated waterglass solution has a viscosity of at least 350 mPa.s at a temperature of 45Â° C. and wherein said viscosity substantially prevents the paper from being impregnated with said waterglass solution at room temperature; c) cooling the immersed paper with air at a temperature no grater than 35Â° C. d) producing from said cooled paper a waterglass-impregnated fiber matrix followed by a chemical conversion of the waterglass on said paper to produce a moisture exchange element; and e) impregnating said moisture exchange element with at least one aqueous solution of a hygroscopic salt and a water soluble substance that inhibits the growth of microorganisms.