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:
Dec. 12, 1995
Filed:
Mar. 01, 1994
Chung P Park, Pickerington, OH (US);
Gerald A Garcia, Newark, OH (US);
Roby G Watson, Newark, OH (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
A low density foam having a density less than 15 pounds per cubic foot (240 kg/m.sup.3) is formed from an amorphous polyethylene terephthalate polymer. An expandable resin composition is also disclosed, comprising an amorphous polyethylene terephthalate polymer and a blowing agent mixture comprising a low permeability blowing agent and a high solubility blowing agent. Unexpanded and partially expanded foam particles, impregnated with the blowing agent mixture are disclosed. Numerous methods are disclosed for producing lightweight foams from amorphous polyethylene terephthalate polymers. One such method utilizes an Accumulating Extrusion Expansion System which avoids problems experienced with the prior art when attempting to extrusion expand polyesters.