Methods for controlling polymer chain scission
US10471641B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 20, 2016 |
| Grant date | Nov 12, 2019 |
| Priority date | — |
| Expiry date | Aug 10, 2036 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P70/10
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Methods for extrusion of polyolefins (110) that utilize melt temperature to control molecular weight and also reduce gels. Disclosed herein is an example method for controlling polymer chain scission in an extrusion system (100), comprising: melting a polyolefin resin (110) in extruder (102) at a first melt temperature to form a first melt (112); passing the first melt (112) through a screen pack (106); forming the first melt 112) into a first polyolefin product (116, 118); melting additional polyolefin resin (110) of the same grade in the extruder (102) at a second melt temperature to form a second melt (112), wherein the second melt temperature differs from the first melt temperature by 5° C. or more to control chain scission in the extruder (102); passing the second melt (112) through the screen pack (106); and forming the second melt (112) into a second polyolefin product (116, 118).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.