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:
Jan. 14, 1992
Filed:
Nov. 21, 1989
Heinz Herrmann, Stuttgart, DE;
Dieter Rath, Esslingen, DE;
Werner & Pfleiderer, GmbH, , DE;
Abstract
The removal of impurities, for example monomeric low-molecular substances, solvents or the like, from polymeric synthetic plastics materials takes place by the admixture of extraction gas in a first extruder in a supercritical state. The mixture is transferred to a second extruder where, in a first separating zone, and by a counter-current method, it is cleansed of the major part of the extraction gas containing the impurities, this being passed through a discharge orifice. Separation of any residue takes place in a vacuum zone on the downstream side. The high pressure in the first extruder is maintained by a counter-pressure valve in the connecting pipe between the first and second extruders. By the separation of contaminated extraction gas from molten synthetic plastics material in a closed space, namely the second extruder, it is possible to achieve an ordered dissipation of extraction gas on the one hand and molten synthetic plastics material on the other hand.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile