Extrusion process for preparing orientated polyolefins
US4948545A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 1989 |
| Grant date | Aug 14, 1990 |
| Priority date | — |
| Expiry date | Oct 6, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2023/00
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An orientated polyolefin composition comprising an olefin (co)polymer having a weight average molecular weight (Mw) from 30,000 to 1,000,000 and a high molecular weight tail extending to molelcular weights above 1,000,000, and has a microstructure which is substantially parallel chain extended cores of the component polymer(s) and associated lamellar overgrowths extending in planes normal to the cores in which the lamellar overgrowths on adjacent cores intermesh and are capable of sustaining a haul off tension of at least 10 MPa without breaking during its extrusion, is produced by extruding an olefin copolymer through a die under a pressure of about 5-10 MPa, at a temperature above the self-blocking temperature thereof and by hauling off the extrudate at a tension of at least 10 MPa without breaking. The extrudates so produced have a high modulus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.