Title:
BLOWING AGENT INTRODUCTION SYSTEMS AND METHODS
Document Type and Number:
WIPO Patent Application WO2004039552
Kind Code:
A3
Abstract:
The present invention provides blowing agent introduction systems (10) and methods for introducing blowing agent into polymeric foam processing systems. The methods may involve introducing one or more doses of blowing agent into polymeric material in an extruder (12) during a plastication period of a molding cycle. Prior to introduction, a dose is confined in an accumulator (20) which, for example, has a volume defined between an inlet valve (28) and an outlet valve (30). A control system (29) may receive inputs related to system parameters (e.g., pressure of polymeric material in extruder, axial position of screw in barrel, whether screw (34) is rotating, and the like) and based on the inputs coordinates operation of the valves to confine and introduce the blowing agent dose(s). The introduction systems may be used in discontinuous plasticating processes, such as injection molding and blow molding, and can be particularly useful in processes that use precise quantities of blowing agent.
Inventors:
KIM ROLAND
Application Number:
PCT/US2003/034216
Publication Date:
September 16, 2004
Filing Date:
October 28, 2003
Export Citation:
Assignee:
TREXEL INC (US)
International Classes:
B29C44/34; B29C44/60; B29C48/92; (IPC1-7): B29C44/34; B29C44/60
Domestic Patent References:
| WO2002014044A1 | 2002-02-21 |
Foreign References:
| EP0574051A1 | 1993-12-15 | |||
| US4613471A | 1986-09-23 |
Download PDF:
Previous Patent: PROCESS AND APPARATUS FOR MICROREPLICATION
Next Patent: LITHOGRAPHIC METHOD FOR FORMING MOLD INSERTS AND MOLDS
Next Patent: LITHOGRAPHIC METHOD FOR FORMING MOLD INSERTS AND MOLDS