The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 08, 2003
Filed:
Sep. 28, 2001
Katsuya Maruyama, Hiratsuka, JP;
Takeshi Hara, Hiratsuka, JP;
Yoshihiro Terada, Tokyo, JP;
Takao Ota, Tokyo, JP;
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
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 second molten resin in the second resin-flow-passage.