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:
Aug. 22, 1978
Filed:
Mar. 23, 1976
Louis C Rubens, Midland, MI (US);
Willard E Alexander, Midland, MI (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
Shaped articles of organic polymer resins having cellular (foamed) structure are made from heat-expandable normally solid thermoplastic resin compositions in permeable molds particularly characterized by flooding the mold cavity and the expandable material therein with molten salt as heating medium. For example, a permeable mold, charged with pieces of polyethylene containing azobisformamide and crosslinked by electron irradiation, is immersed into a molten salt eutectic mixture of KNO.sub.3, NaNO.sub.2 and NaNO.sub.3 at about 264.degree. C, removed, cooled and washed with water, thereby forming a coherent, unitary cellular resin molded article completely filling the mold cavity.