Process for producing polyester articles having low acetaldehyde content
US5597891A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 1, 1995 |
| Grant date | Jan 28, 1997 |
| Priority date | — |
| Expiry date | Aug 1, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2105/0002
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Disclosed is a process for removing acetaldehyde from polyester which comprises the steps of PA1 a) transporting molten polyester to a vented, continuous screw conveyor having a polymer compression zone, PA1 b) rotating the screw of said conveyor so as to compress and convey through the extruder the molten polymer for a time of less than 15 minutes and at a temperature of less than 300.degree. C., PA1 c) simultaneously with step b), flowing a purge agent into and out of said extruder to thereby remove volatile impurities and avoid appreciable build-up of acetaldehyde, and PA1 d) conveying the devolatized polymer melt to a mold wherein an article of manufacture is formed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.