Process for rapid curing of polyether polyurethane foam
AssigneeReeves Brothers, Inc.
InventorAzel A. Griswold
Life of this patent
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Abstract
A process for the rapid post curing of polyether polyurethane foam in the form of porous blocks in which the foam is subjected to a mixture of water vapor and gaseous ammonia, primary or secondary amines at a temperature of about 50.degree. to 150.degree. F. for a period of 1 or more minutes. The cured foam recovers its original dimensions when distorted or compressed after the distortion or compression force is released.
Claims10
A process for the rapid post curing of polyether polyurethane foam blocks without adversely affecting the compression set of said foam which process comprises subjecting said polyether polyurethane foam having a porosity of greater than about 3 cubic feet per minute to a mixture of air and gaseous ammonia, primary or secondary amine at a temperature of above about 50.degree. F., wherein the amount of ammonia, primary or secondary amine is present at a concentration of at least 0.5% by volume of the air, the air has a relative humidity above about 50% and the air/ammonia or primary amine mixture reacts with the foam for a period of at least one minute.
A process for the rapid post curing of polyether polyurethane foam blocks having a porosity greater than about 3 cubic feet per minute without adversely affecting the compression set of said foam which comprises
- (a) positioning said block in a confined space,
- (b) opening the skin on the top and bottom of said block to gas flow,
- (c) passing a mixture of gaseous ammonia or primary amine and air wherein ammonia, primary or secondary amine is present in a concentration of about 0.5% by volume, said air having a humidity at least above about 50% into one side of said block,
- (d) maintaining a vacuum on the opposite side of said block,
- (e) continuing to pass the air/ammonia or primary amine mixture through said block for at least one minute, while maintaining the temperature at about 50.degree. F.
Dependencies are inferred from the claim text.