Back to results
US 5,700,407 AGranted
Molded polymeric foam preparation method
OwnerRobert Michael Brangerinventor
Life of this patent
Estimating the term…
Abstract
Foamed articles having excellent properties are prepared by partially filling a mold with foamable composition, pressurizing the mold while heating to activate blowing agent and crosslinking agent, and releasing the pressure while the polymer is at least partially crosslinked to permit the foam to fill the mold.
Claims9
A process for the preparation of foamed polymeric articles consisting essentially of:
- (a) formulating a foamable polymer composition comprising polymer, crosslinking agent and blowing agent, the blowing agent having a decomposition temperature;
- (b) heating a mold to a temperature higher than the decomposition temperature of the blowing agent;
- (c) filling less than about 25% of the volume of the mold with the foamable composition, sealing the mold and pressurizing the sealed mold with inert gas to a pressure of at least about 500 psi;
- (d) heating the foamable polymer composition to above the decomposition temperature of the blowing agent and above the activation temperature of the crosslinking agent;
- (e) maintaining the pressure within the mold to maintain the resulting decomposed blowing agent substantially in solution within the foamable polymer composition until the polymer in the foamable polymer composition is at least partially crosslinked;
- and
- (f) releasing the pressure within the mold.
4 more elements
A process for the preparation of foamed polymeric articles consisting essentially of:
- (a) formulating a foamable polymer composition comprising polymer, crosslinking agent and blowing agent, the blowing agent having a decomposition temperature, wherein the polymer consists essentially of ethylene/vinyl acetate copolymer;
- (b) heating a mold to a temperature higher than the decomposition temperature of the blowing agent;
- (c) filling up to about 50% of the volume of the mold with the foamable composition, sealing the mold and pressurizing the mold with inert gas to a pressure of at least about 500 psi;
- (d) heating the foamable polymer composition to above the decomposition temperature of the blowing agent and above the activation temperature of the crosslinking agent;
- (e) maintaining the pressure within the mold to maintain the resulting decomposed blowing agent substantially in solution within the foamable polymer composition until the polymer in the foamable polymer composition is at least partially crosslinked;
- and
- (f) releasing the pressure within the mold.
4 more elements
Dependencies are inferred from the claim text.