Blend composition containing recycled polycarbonate and recycled polymethylmethacrylate
US5569713A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 5, 1995 |
| Grant date | Oct 29, 1996 |
| Priority date | — |
| Expiry date | Jun 5, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/046
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A close loop thermoplastic recycling process includes the step of testing particulated processed plastic material to determine the properties thereof. The tested properties are compared with targeted near virgin properties of the processed plastic material to determine any difference(s) therebetween. Additives based on the property differences determined during testing are admixed with the particulates in a twin screw extruder. During extruding, volatile constituents are simultaneously withdrawn from the fused particulates. The twin screws of the extruder are provided with a number of screw sections, each having a thread with predetermined degrees of chamfer and pitch length. Kneading blocks are mounted on certain screw sections prior to a vacuum vent port disposed along the feed path of the melt stream in the extruder. The extruded material is tested to determine if any property differences exist. If no unacceptable tested differences are found, the extruded material is prepared for reuse in place of or in conjunction with virgin plastic material having the same properties and characteristics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.