Patent ID: 6228478
Filing Date: 2001-05-08
Classification: B60R,C08J,G10K,Y10S,Y10T

Abstract:
A method of manufacturing a composite foam having a density, elastic modulus and loss factor so as to provide a finished composite foam product having sound dampening acoustical properties, said method comprising the steps of:(a) wetting reclaimed foam flakes of differing reclamation origins with 5 wt. % to 20 wt %, based on the weight of the foam flakes, of an aqueous polyurethane dispersion binding agent, said binding agent comprising a 1:1 mixture with water of an NCO-prepolymer with blocked isocyanate groups and containing a polyamine component having primary and/or secondary (cyclo) aliphatically bonded amino groups;(b) forming the wetted foam flakes into a molded part or continuous web;(c) hardening the molded part or continuous web by applying hot (water) steam or microwave energy; and(d) drying the hardened molded part or continuous web with hot air and/or vacuum,wherein the density is greater than 150 kg/m.sup.3, the elastic modulus is in the range between 50,000 and 140,000 N/m.sup.2 and the loss factor is greater than 0.2.