Swell reducing extrusion die
US5874034A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 1997 |
| Grant date | Feb 23, 1999 |
| Priority date | — |
| Expiry date | Apr 14, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C48/305
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The present invention includes a method and apparatus for extruding viscoelastic polymers. Specifically, the invention is directed to an extrusion die for manufacturing viscoelastic and similar polymers while reducing or eliminating die swell. These polymers typically exhibit Deborah numbers that are in the range of 20 to 30 as compared to 1 to 5 of styrene butadiene, as well as high elasticity or elastic modulus. The method and apparatus can be used to manufacture xerographic toner that has a relatively low melting temperature, which can cause a reduction in the power consumption of a printer or copier, and can increase the life of some of the fuser components contained within the machine. More importantly, use of toner particles created using the present invention can reduce or eliminate the phenomenon known as "vinyl off set," which causes the transfer of a hard copy image onto a vinyl material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.