Polymer foam thermoformation process and apparatus therefor
AssigneeMobil Oil Corporation
InventorsCharles M. Krutchen, Wen-Pao Wu
Life of this patent
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Abstract
A method of thermoforming comprising providing a continuous sheet of thermoplastic polymeric foam, transporting said sheet through an atmosphere of at least predominantly steam at a temperature of at least 215.degree. F. maintaining said sheet in said atmosphere for a time sufficient to cause a decrease in the density thereof; thereafter while under the influence of said temperature, deforming at least a portion of said sheet to a predetermined shape and while so deformed, cooling the same to cause retention of said shape and a system for carrying out said method.
Claims7
A method of thermoforming comprising:
- (a) providing a continuous sheet of thermoplastic polymeric foam;
- (b) transporting said sheet thru an atmosphere of at least predominantly steam at a temperature of at least 215.degree. F., any non-steam component being composed of air;
- (c) maintaining said sheet in said atmosphere for a time sufficient to cause a decrease in its density;
- (d) thereafter while under the influence of said temperature, deforming at least a portion of said sheet to a predetermined shape;
- and
- (e) while so-deformed, cooling the same to cause retention of said shape.
A system for thermoforming a continuous sheet of thermoplastic foam comprising in combination:
- (a) means for transporting said foam in single layer form;
- (b) means for treating said foam, during its transport in single layer form, with an atmosphere of predominantly steam at a temperature of at least 215.degree. F., any non-steam component being composed of air;
- and
- (c) means in association therewith for receiving said sheet in thermoformable condition, for deforming at least a portion of said sheet to a predetermined shape and for cooling the same to retain said shape.
Dependencies are inferred from the claim text.