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:
Nov. 13, 2001
Filed:
Nov. 05, 1999
Gefinex Polymerschaeume GmbH, Steinhagen, DE;
Abstract
A method for producing a foamed granulate, wherein a thermoplastic synthetic material is placed in an extruder, the synthetic material is melted, a pressurized expanding agent is fed through one or several injection nozzles, the molten material enriched with the expanding medium is foamed as it exits through a perforated plate arranged at the outlet of the extruder and is granulated by a cutting device arranged behind the perforated plate. Also disclosed is a device for implementing the method and the foamed granulate. The invention is characterized in that the molten material is cooled in a controlled manner as it comes out of the perforated plate and exits directly into a flowing cooling medium, in that the temperature of the molten material and the temperature and pressure of the cooling medium are regulated in such a way that once the molten material exits the perforated plate, the surface of the molten material is directly hardened into a closed film with a smooth surface having a thickness that ranges from 10 to 500 &mgr;m, preferably 20 to 200 &mgr;m, whereupon the molten material is foamed and a granulate with a rounded surface and a bulk density of 10 to 600 g/l is formed. A semi-spherical granulate with a smooth surface is thus obtained.