Screw machine for the continuous degradation of plastics
US4136967A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 1977 |
| Grant date | Jan 30, 1979 |
| Priority date | — |
| Expiry date | Jul 18, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/62
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An apparatus for hydrolytic degradation of plastics in which plastic material is deposited into a tubular housing via a feed hopper. An elongated screw shaft has a first section in the form of a high pitch screw thread disposed below the feed hopper to receive and advance the material to a second section. The second section of the screw shaft is in the form of a lower pitch thread for compressing the plastic material and transferring it to a longer, third section in the form of kneading discs, from which material passes through an outlet nozzle section to a cyclone separator where trapped gases and liquid may be withdrawn. The tubular housing is vented upstream of the feed hopper and a water inlet pipe is disposed adjacent to the second section of the screw shaft, downstream of the feed hopper. The outlet nozzle section is provided with pressure measuring and regulating means and a liquid level measuring and regulating device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.