Injection molded body, injection molding method, and injection molding die

Patent metadata

Field	Value
Publication number	US-10695965-B2
Application number	US-201414909076-A
Country	US
Kind code	B2
Filing date	Jul 28, 2014
Priority date	Jul 30, 2013
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

A method for making a synthetic resin injection molded body that is gate-cut by die opening after injection molding by means of a pinpoint gate 9 . A cavity 10 is filled with a molten resin, from a first sprue 6 that is provided coaxially with the injection direction of the molten resin, through a runner 7 that is provided in the perpendicular direction to the first sprue 6 , via a pinpoint gate 9 that is formed on a tip part of a second sprue 8 that is provided horizontally to the injection direction of the molten resin, from a gate port 9 a of the pinpoint gate 9 formed on a cavity plane that is in parallel with the die opening direction; after cooling, gate cutting is performed by means of die opening; and a molded body is taken out in an ejection step.

First claim

The invention claimed is:

1. A synthetic resin injection molded body that has been gate-cut by means of die opening after injection molding by means of a pinpoint gate, wherein the synthetic resin is a synthetic resin having a tensile elongation at break of 100% or more, wherein the injection molded body is an approximately-cylindrical molded body having a bearing part that constitutes a bearing hole, and a guide part, the bearing part and the guide part being connected to each other at a central portion of the injection molded body in an axis direction, wherein the injection molded body has a gate mark, the gate mark being located on an outer diameter surface of the bearing part, which is a surface parallel to the axis direction of the molded body, and facing the inner surface of the guide part, wherein the gate mark does not have a resin string resulting from a stretch of the synthetic resin.

2. The injection molded body according to claim 1 , wherein the injection molded body is a guide member for an electrophotographic device.

3. The injection molded body according to claim 1 , wherein the synthetic resin is at least one synthetic resin selected from a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, a tetrafluoroethylene-ethylene copolymer and a tetrafluoroethylene-hexafluoropropylene copolymer.

Assignees

• Ntn Toyo Bearing Co Ltd

Inventors

• Abe Hirohisa
• Fukuzawa Satoru

Classifications

• C08J5/00

  Manufacture of articles or shaped materials containing macromolecular substances (manufacture of semi-permeable membranes B01D67/00 - B01D71/00) · CPC title

• B29C45/2708

  Gates (B29C45/2703 takes precedence) · CPC title

• B29C45/38 Primary

  Cutting-off equipment for sprues or ingates · CPC title

• C08J2327/18

  Homopolymers or copolymers of tetrafluoroethylene · CPC title

• C08J2329/10

  Homopolymers or copolymers of unsaturated ethers (C08J2335/08 takes precedence) · CPC title