Extruder screws
US4015832A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 31, 1975 |
| Grant date | Apr 5, 1977 |
| Priority date | — |
| Expiry date | Jan 31, 1995 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C48/03
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A plasticating extruder screw is provided with a wave section in which the depth of the material conveying channel varies cyclically over a plurality of cycles. The wave section as a whole provides good pumping performance for metering the extrudate at a uniform rate. The deep valley portions of the wave section minimize heat inputs to the material being fed, and the shallow ridge portions of the wave section assure repeated intensive mixing of the material for providing high quality polymer melts. The minimum channel depth portions are in a balanced relationship about the axis of the screw to avoid lateral thrust problems. Such balance may be achieved in successive cycles of a single channel or as between adjacent channels of a multiple channel screw. The wave may be in the metering section of a single stage screw or in any of the pumping sections of a multiple stage screw.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.