GB468106A - A new felted fibrous cellulosic sheet product - Google Patents

Abstract

468,106. Felted fibrous cellulosic sheets. BURGESS, A. F. (Paper Patents Co.) Aug. 7, 1936, No. 21786. Drawings to Specification. [Class 96] A felted fibrous cellulosic product in the form of a crÛped sheet of gossamer thinness is made from a furnish in which there has been mixed 10-50 per cent of asphalt which is relatively brittle at room temperature and has a melting point between 140‹ F. and 200‹ F. A number of such sheets may be combined to form a multiply bat or pad for use as a heat or sound insulating material. Preferably the crÛped sheets have a basis weight of 4À9 lbs. for 480 sheets (24" x 36"). The sheets are made upon machines as ordinarily employed for making thin sheets for packing wadding, and are dried upon a Yankee drier from which they are removed by a crÛping doctor. The sheets are water repellent and may readily be fireproofed e.g. by spraying suitable solutions on to the drying web. Alkaline adhesive solutions such as sodium silicate may also be applied to the asphalt containing products without adversely affecting their water repellent characteristics. In an example, two parts of commercial asphalt having the desired properties are mixed with one part of ground wood and one part of unbleached sulphite fibre, and the furnish supplied to the machine contains 400 lbs. of this mixture together with 300 lbs. of unbleached sulphite pulp and 300 lbs. of ground wood. The sheets contain 20 per cent asphalt by weight. Sheets with 10 per cent asphalt are made from a furnish containing 200 lbs. of the mixture and 80 lbs. of unbleached sulphite pulp. In either case sufficient water is mixed with the furnish in the beaters to produce pulp suspension of about 3 per cent which is pumped to the paper making machine when it may be thinned with additional circulating water.