Screw plastifying and conveying device of an injection molding machine for plastics
US4648827A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 1984 |
| Grant date | Mar 10, 1987 |
| Priority date | — |
| Expiry date | Sep 21, 2004 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C48/53
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A screw plastifying and conveying device includes a screw (5) which has a pull-in zone (I) of constant pitch volume (V.sub.0), a first compression zone (II), and adjacent thereto, i.e. in the injection side, a second compression zone (III). The compression ratio (V.sub.1 :V.sub.0) of the second compression zone (III) is between 1:1.0 and 1.2, while that of the first compression zone is between 1:1.6 and 1:4. This makes it possible, by underdosing, to reduce the melt volume in the second compression zone, thereby achieving stable conveying action over a wide operating range. Molded parts with minimal internal tensions and e.g. also molded parts of glass-clear material with unobjectionable optical properties can thus be produced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.