Semi-continuous production of solid state polymeric foams
AssigneeUniversity of Washington
InventorsVipin Kumar, Henry G. Schirmer
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Abstract
The present invention provides a method for the semi-continuous production of microcellular foam articles. In a preferred embodiment, a roll of polymer sheet is provided with a gas channelling means interleaved between the layers of polymer. The roll is exposed to a non-reacting gas at elevated pressure for a period of time sufficient to achieve a desired concentration of gas within the polymer. The saturated polymer sheet is then separated from the gas channelling means and bubble nucleation and growth is initiated by heating the polymer sheet. After foaming, bubble nucleation and growth is quenched by cooling the foamed polymer sheet.
Claims27
A method for foaming polymeric materials, comprising the steps of:
- (a) interleaving an article of polymeric material with a gas channeling means;
- (b) exposing the interleaved article at elevated pressure to a non-reacting gas which is soluble in the polymer for a time sufficient to achieve a desired concentration of gas within the polymer, thereby forming an exposed polymeric article which is at least partially gas-saturated;
- (c) separating the exposed polymer article from the interleaved gas channelling means;
- and
- (d) heating the exposed polymer article sufficiently to initiate bubble nucleation and to achieve desired bubble growth.
Dependencies are inferred from the claim text.