Screw-type extruder for polyvinylidene fluoride filaments
US4280802A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 1980 |
| Grant date | Jul 28, 1981 |
| Priority date | — |
| Expiry date | Feb 22, 2000 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C48/05
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An apparatus for the continuous manufacture of filaments from polyvinylidene fluoride includes a screw extruder with a single-spindle screw surrounded by a coaxial barrel with a feed zone, a compression zone, a metering zone, and a mixing head zone for the plasticizing of the polyvinyldene fluoride and with a die outlet tool for shaping the filaments. The compression ratio of the screw is 1:1.2 to 1:2.5, and the screw is provided with single-flight and double-flight sections of identical pitch in alternating succession in the region of the compression zone. The mixing head zone is fashioned as alternatingly successive mixing zones and shear zones, of which there are provided, respectively, two to four zones and preferably three zones.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.