Method of injection molding multi-layered articles
US6544459B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 2001 |
| Grant date | Apr 8, 2003 |
| Priority date | — |
| Expiry date | Oct 16, 2021 |
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, which 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 having 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 being provided with back flow means 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 means being operable with a pressure which the first molten resin in the first resin-flow-passage exerts on se…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.