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. 07, 2009
Filed:
Oct. 11, 2002
Detlef Gneuss, D-32545 Bad Oeynhausen, DE;
Wieslaw Walach, D-53842 Troisdorf, DE;
Detlef Gneuss, D-32545 Bad Oeynhausen, DE;
Wieslaw Walach, D-53842 Troisdorf, DE;
Other;
Abstract
The invention concerns an extruder for producing molted plastic materials from plastic granules available on the market, by heating and mixing granules, with heated single- or double-screw extruders, and for carrying out polycondensation or polymerization using part of a multiple-screw extruder and by means of vacuum chambers for removing the constituents of low molecular weight and/or foaming agents or the like, for obtaining larger molecules and hence a higher viscosity, and for increasing the mechanical strength of plastic materials produced from said molten material. The invention aims at designing said extruder such that the molten material can be processed in thin layers enabling exposure of large surfaces in contact with the vacuum, and hence a molten plastic material ensuring desired levels of degassing and polymerization using simple means. Therefor, the envelopes of the stems of the screws () are mutually spaced apart at least in the polycondensation zone of said extruder part with multiple screws (), relative to the extruder screw () or its shaft section () and relative to cylindrical zones enclosing them, by a distance not less than zero (≧0).