The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 10, 1979
Filed:
Jun. 18, 1975
Walter H Smarook, Somerville, NJ (US);
Union Carbide Corporation, New York, NY (US);
Abstract
A low pressure process for expanding the cross-section of a blank of thermoformable material between a pair of mold plates having perforation means therein, with the perforation means of one plate being selectively out of alignment with the perforation means in the second plate, the expansion leading to the formation of one or more voids having a partial vacuum or reduced pressure within the cross-section of the blank, which comprises venting the voids during the expansion of the cross-section so as to equilibrate the level of pressure within the voids with the level of pressure without the blank so as to thereby regulate the uniformity and integrity of the resulting cross-sectional geometry of the expanded blank. Products having an expanded cross-section are formed by such process.