Removal of residual acetaldehyde from polyester polymer particles
US7863405B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 2004 |
| Grant date | Jan 4, 2011 |
| Priority date | — |
| Expiry date | Dec 21, 2024 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29B2009/165
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
In one embodiment, there is provided a process comprising introducing polyester polymer particles containing residual acetaldehyde into a vessel at a temperature within a range of 130° C. to 195° C. to form a bed of particles within the vessel, flowing a gas through at least a portion of the particle bed, and withdrawing finished particles from the vessel having a reduced amount of residual acetaldehyde. In this process, it is not necessary to introduce a hot flow of gas at high flow rates otherwise required to heat up cool particles to a temperature sufficient to strip acetaldehyde. Rather, this process provides a benefit in that, if desired, gas introduced into the vessel at low flow rates and low temperatures can nevertheless effectively strip acetaldehyde in a reasonable time because the hot particles quickly heat a the gas to the particle temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.