Patent ID: 6841586

Claim:
A method far making a hydrophilic ester polyurethane foam, comprising: (a) forming a polyurethane foam by mixing together the following components: (i) 100 parts by weight of an ester polyol mixture, wherein at least 5.0 parts by weight of the ester polyol mixture comprises a hydrophilic polyester polyol made from an adipic acid and a polyethylene glycol; (ii) from 20.0 to 62.0 parts by weight, based on 100 parts polyol, of an isocyanate, wherein the isocyanate index is 120 or less; and (iii) from 1.0 to 3.0 parts by weight, based on 100 parts polyol, of a silicone stabilizing surfactant; (b) treating the polyurethane foam in a caustic bath to form the hydrophilic ester polyurethane foam, and (c) felting the treated foam, wherein the hydrophilic ester polyurethane foam has a water absorption rate of at least 20 pounds of water per square foot per minute.