Process for rapid cooling of polyurethane foam
AssigneePMC, Inc.
InventorHerman Stone
Life of this patent
Estimating the term…
Abstract
An improved process for rapidly cooling hot freshly polymerized foam is provided by passage of a fluid coolant stream having a water vapor content which initially is in the range from slightly below to above the dew point. In preferred embodiments the cooling fluid stream is recirculated, and auxiliary blowing agents and gaseous reaction products are removed and recovered.
Claims20
In the process for preparing an open cellular flexible polyurethane foam mass having more uniform physical properties by passing a draft of gas through the foam mass which has substantially completed the polymerization reaction in order to cool the foam rapidly and uniformly, the improvement which comprises contacting the freshly polymerized foam with a fluid coolant stream having a water vapor content which initially is in the range from slightly below to above the dew point, said stream being initially free of ammonia and amines.
In the process for preparing an open cellular polyurethane foam mass having improved physical properties by passing a draft of gas through the freshly made foam mass which has substantially completed the polymerization reaction in order to cool the foam rapidly and uniformly, the improvement which comprises the steps of:
- (a) contacting the foam with a first fluid coolant stream having a water vapor content which initially is at, or near the dew point, said stream being initially free of ammonia and amines;
- and
- (b) contacting the foam with at least one additional fluid coolant stream, said additional stream being initially free of ammonia and amines, the initial temperature of second and any successive streams being less than the temperature of the preceding stream.
A flexible, open cell polyurethane foam having improved tensile properties which is obtained by contacting the freshly produced foam mass which has substantially completed the polymerization reaction with a fluid coolant stream having a water vapor content which initially is essentially at, or above the dew point, said stream being initially free of ammonia and amines.
Dependencies are inferred from the claim text.