Process for forming thermoplastic material from granular scrap material
US4970043A · kind A · utility
Inventors
Key dates
| Filing date | Feb 27, 1989 |
| Grant date | Nov 13, 1990 |
| Priority date | — |
| Expiry date | Feb 27, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S264/912
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process forming a moldable material from a granular scrap material such as a high grade reground rubber and a thermoplastic polymer such as a butadiene-styrene block copolymer sold under the trademark Kraton-D-3202 by Shell Chemical Company. A substantially uniformly distributed mixture of the reground rubber and the cohesive base material in a ratio of at least about 1:1 is processed under sufficient pressure and temperature to form a semi-stable moldable product. The semi-stable moldable product is then subjected or maintained under sufficient pressure to form a stable moldable product. The ratio of reground rubber to cohesive base material may be 7:3 or higher, while pressure on the semi-stable product may generally be in the range of 1800 psi or higher. The moldable product may be subsequently molded, preferably with high fill velocities and maximum venting.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.