Patent ID: 6883575

Claim:
A method of making a wet laid nonwoven mat bound with a novolac resin comprising the steps of: a) dispersing fibers and novolac resin particles in water to form a dilute slurry, b) flowing said slurry onto a moving first permeable belt to form a wet layer of wet nonwoven fibers and resin particles, c) transferring said wet layer off of said permeable belt onto a second moving permeable belt, d) saturating said wet layer with an aqueous solution or slurry containing a crosslinking agent and removing excess slurry or solution and excess crosslinking agent from said wet layer, e) transferring said wet layer off of said second permeable belt onto an oven belt, and f) drying said wet layer to form a dry mat, the improvement comprising that said resin is a novolac powder having an acetone solubility greater than 95 wt. percent, that the aqueous solution or slurry contains a hardening agent for the novolac, the amount of said resin and hardening agent in the finished dried mat is at least 10-65 wt. percent, and said novolac resin is in contact with the hardening agent and is cured sufficiently reduce the acetone solubility to between about 35 and about 95 weight percent to give sufficient strength to the mat for handling and further processing, but not so much that the mat looses its ability to conform to a desired shape and bond to another mat or different material under heat and pressure.