Injection molding apparatus for molding multi-layered articles
US6322344A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 1998 |
| Grant date | Nov 27, 2001 |
| Priority date | — |
| Expiry date | Sep 22, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2949/3038
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An injection molding apparatus for injection molding a multi-layered article is disclosed. The apparatus comprises; (a) a mold having a cavity block provided with a cavity and a hot runner block, (b) at least a first injection cylinder and a second injection cylinder, (c) a first resin-flow-passage for connecting an inside of the first injection cylinder and the cavity, and (d) a second resin-flow-passage for connecting an inside of the second injection cylinder and the cavity. The injection molding apparatus has a structure in which those portions of the first and second resin-flow-passages which are located within the mold are provided in the hot runner block, and the first resin-flow-passage and the second resin-flow-passage meet with each other in a junction portion upstream to a gate portion opened to the cavity. The injection molding apparatus is provided with a back flow device for letting first molten resin in the first resin-flow-passage flow into the second resin-flow-passage after second molten resin is injected into the cavity through the second resin-flow-passage. The back flow device is operable in response to pressure which the first molten resin in the first resin-f…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.