Patent ID: 10894343

Abstract:
A rigid nylon porous material sheet is produced by the adhesive bonding of kinked nylon fibers having lengths of 1 to 5 inches. These fibers are cut from melt spun nylon or harvested from clean carpet fibers by shearing. The adhesive used is glycol, which attacks nylon at 180° C. forming a gel on the surface of the kinked fibers, but does not attack the nylon fibers when the kinked fiber assembly is cooled to 150° C. to precipitate ultrafine nylon within the gel. The fiber assembly is heated to 160° C. to bond the nylon fibers. It is then washed in hot water to remove unused glycol. The other adhesive is polyurethane, which is applied to the kinked fibers using coupling agents of aqueous resorcinol and vinyl pyrrolidone.