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:
Sep. 25, 1990
Filed:
Sep. 22, 1988
Rudiger Dollhopf, Herbolzheim, DE;
Bernd Nandzik, Gundelfingen, DE;
Rhodia AG, Freiburg, DE;
Abstract
In the case of the extruder, the thread of the screw, or that of the screws, is partly left-handed and partly right-handed, so that one part of the material to be processed is conveyed in direction A, while the other part is conveyed in the opposite direction B. The process is a degasifying-extrusion-process and the extruder is a degasifying extruder. The apparatus includes a reverse-degasifying assembly (7,22) at the end (8,19) of the screw (1,16), or screws (1,16), if the material to be processed is carried away from this end, and/or a reverse-degasifying assembly (41,52) at the location between the threaded sections of the screw (1,16) or screws (1,16), so that the material to be processed is carried away in opposite directions B and A. According to the invention, continuous operation is possible, no dead areas and break-away edges are formed, the reverse-degasifying assembly (7,22,41,52) is easily sealed off against any entry of oxygen, products sensitive to heat and oxidation, such as polyamide-66, may also be produced, without damage, in continuous operation, for example by synthetic-fibre extrusion spinning.