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:
Oct. 31, 1995
Filed:
Jul. 13, 1994
George A Serad, Charlotte, NC (US);
Theodore S Thornburg, Rock Hill, SC (US);
Hoechst Celanese Corporation, Somerville, NJ (US);
Abstract
A method for separating co-mingled polymeric materials, in particular polyethylene terephthalate (PET) and polyvinyl chloride (PVC) is described. The process involves selectively dissolving a supercritical fluid into one of the materials at the appropriate temperature and pressure. Upon rapid reduction of the system pressure, the selected material foams providing a change in density. Under ambient conditions, the polymeric materials having a large density difference can be separated by means of aqueous separation and flotation. The preferred supercritical fluid for the process is carbon dioxide, and PVC is the material into which the supercritical fluid is preferentially dissolved.