Patent ID: 6733628
Filing Date: 2004-05-11
Classification: B01J,C04B,D21H

Abstract:
A method of making a mat having a substantially consistent density across its area, the method comprising:(a) forming an aqueous slurry containing fibres, wherein a major proportion are refractory fibres and a minor proportion are thermoplastic fibres which comprise fibres having two different melting points, one lower than the other; (b) adding a binder and a flocculating agent; (c) passing the slurry containing the refractory fibres, thermoplastic fibres, binder and flocculating agent through a perforate screen to deposit a body of wet fibres on the screen; (d) heating the body to remove the water and melt the lower melting point fibres to form a preform; and (e) thermoforming the preform under pressure to form the mat.