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. 15, 2008
Filed:
Aug. 10, 2004
Michel Florentine Jozef Berghmans, Calgary, CA;
Karel Cornelis Bleijenberg, Presto, PA (US);
Joachim Teubert, Blumberg, DE;
Alphonsus Catharina Gerardus Metsaars, Rijen, NL;
Michel Florentine Jozef Berghmans, Calgary, CA;
Karel Cornelis Bleijenberg, Presto, PA (US);
Joachim Teubert, Blumberg, DE;
Alphonsus Catharina Gerardus Metsaars, Rijen, NL;
NOVA Chemicals (International) S.A., Fribourg, CH;
Abstract
Process for processing expandable polymer particles e.g. polystyrene (EPS) that eliminates the maturing step between the pre-expander and molding steps. The expandable particles are first over pressurized with gas, e.g. air, carbon dioxide, nitrogen, and mixtures thereof, at a pressure between 500 and 8000 kPa and a temperature between −20° C. and 130° C. for 15 to 7200 minutes to create a gas pressure in the particles. Using the gas pressure in the particles, pre-expanding the particles with a heating medium, e.g. steam at a temperature between 100° C. and 120° C. and at a pressure ranging above atmospheric pressure and below the gas pressure in said particles, i.e. 50 to 200 kPa for 5 to 120 seconds. The pre-expanded particles are air dried in the pre-expander while holding a positive pressure in the particles; are optionally transferred to a pressure silo; and then are transferred to a molding machine where the gas pressure in the particles is used to form a foam article.