Combination thermoplastic and glass loaded thermosetting injection molding machine and method for operating same
US4280972A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 1, 1979 |
| Grant date | Jul 28, 1981 |
| Priority date | — |
| Expiry date | Oct 1, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2045/001
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An injection molding machine which is capable of injecting both thermoplastic compounds and glass loaded thermosetting polyester compounds, wherein the machine is capable of rapid conversion from its thermoplastic configuration to its thermosetting configuration, and vice versa. The machine comprises an elongated charge forming barrel having a rearward thermoplastic feed opening, which is customarily supplied by pelletized thermoplastic material from a vertical feed hopper, and a thermosetting material feed opening extending into the barrel at a position forwardly of the thermoplastics feed opening. When processing thermoplastics materials, a conventional, fully flighted plasticizing screw is installed in the barrel so that the pelletized material is conveyed forwardly from the rear feed opening, and plasticized for subsequent injection. During thermoplastics processing, the thermosetting feed opening is plugged. To convert the machine to process the aforementioned thermosetting materials, the second feed opening is unplugged, and the plasticizing screw is exchanged for a deeper flighted conveying screw having flights extending from the forward end thereof to just behind the unplug…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.