Patent ID: 7777091

Claim:
A method for preparing a two layer hydrophilic polyurethane foam dressing material with improved moisturizing rate, said method comprising laminating a wound contact layer ( 10 ), having a sponge structure composed of multiple open cells ( 12 ) and pores ( 15 ) passing through the cells ( 12 ), with a protective film ( 20 ) at 150˜250° C. under a pressure of 0.25˜1 kgf/cm 2 , wherein said laminating is by heat-press; wherein the wound contact layer ( 10 ) has a moisturizing rate of 510˜1050% and the pore area (membrane opening) takes 10˜20% of the total cell area; wherein the mean diameter of the open cells ( 12 ) is 50˜300 μm and the mean diameter of the pores ( 15 ) is 5˜85 μm; wherein the ratio of the open cells to the wound contact layer ( 10 ) is 30˜50%; wherein the wound contact layer ( 10 ) has a density of 0.15˜0.45 g/cm 3 ; and wherein the wound contact layer ( 10 ) has a water absorptiveness of 700˜1800 weight %.