Method and apparatus for making crystalline polymeric pellets and granules
US8361364B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 24, 2006 |
| Grant date | Jan 29, 2013 |
| Priority date | — |
| Expiry date | Dec 26, 2027 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2067/046
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method and apparatus for underwater pelletizing and subsequent drying of crystallizing polymers to crystallize the polymer pellets without subsequent heating is shown in FIG. 5. High velocity air or other inert gas is injected into the water and pellet slurry line (120) toward the dryer near the pelletizer exit (102) at a flow rate of from about 100 to about 175 m3/hour, or more. Such high-speed air movement forms a vapor mist with the water and significantly increases the speed of the pellets into and out of the dryer such that the polymer pellets leave the dryer with sufficient latent heat to cause self-crystallization within the pellets. A valve mechanism in the slurry line (150) after the gas injection further regulates the pellet residence time and a vibrating conveyor after the dryer helps the pellets to achieve the desired level of crystallinity and to avoid agglomeration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.