Methods for processing polymers
US5190711A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 18, 1991 |
| Grant date | Mar 2, 1993 |
| Priority date | — |
| Expiry date | Apr 18, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2793/0063
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Method and apparatus for fabricating multiple layer sheet materials while minimizing the time during which a sensitive polymeric melt stream is in contact with metal. The method comprises encapsulating the sensitive melt stream with a second polymeric melt stream, preferably of a lower viscosity, at the outlet of the apparatus which produces the sensitive melt stream. When the encapsulating melt stream has a lower viscosity than the sensitive melt stream, a transport means is preferably employed between the encapsulating means and the die, whereby thickness variations about the circumference of the encapsulating melt stream are reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.