Injection molding device and member used thereof and surface treatment method

Abstract

PURPOSE: An injection molding machine, a constituent member, and a surface treatment method are provided to secure a long service life span and to favorably increase molding efficiency. CONSTITUTION: In an injection molding machine, a portion of a surface contacting with molding resin of a base material(41) forming a resin passage is covered with a protective film(43) made of a diamond-like carbon containing fluorine. A base layer(42) is made of at least one of 4a, 4b, 5a, and 6a groups and formed between the base material and the protective film. A constituent member is a mold or at least one member of a needle, a sprue, a manifold, a heating cylinder, a screw, and a nozzle. The base layer and an intermediate film disposed between the base material and the protective film improve the bonding force of the base material and the protective film and ensure the effect of the protective film for a long time.

Description

technical field [0001] The present invention relates to various injection molding devices and components used thereon such as injection needles, molding dies, gates, manifolds, heating cylinders, screws, nozzles, etc. The injection molding device of the protective film and the components used on it and the surface treatment method are related. Background technique [0002] Since the injection needle is disposed inside the nozzle body that injects the molten resin into the mold, the pressure-fed molten resin can be injected into the mold from the front end of the nozzle body through the slit formed between the nozzle body and the injection needle. Then, after entering the holding pressure, the injection needle is moved a little to seal, and then the resin molded product is taken out from the injection molding device and assembled. [0003] In addition, examples relating to molding dies include Patent Document 1 (JP-A-1-234214). [0004] However, since the injection needle a...

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Problems solved by technology

[0004] However, since the injection needle and the nozzle body are made of ordinary steel, the detachability with the molding resin is not good.

Because, when sealing with such an injection needle, bubble-like protrusions, burrs, and mold release are likely to occur on the sealing part of the molded product.

In addition, since the detachability with the molding resin is poor, resin will adhere around the injection needle and inside the nozzle body at the end of molding, and the attached resin will be burnt and discolored during injection molding, and its ash will be removed from the mold. The injection needle and nozzle body come off and rush into the mold and mix into the molded product

As a result, there will be disadvantages such as lower product prices, and worse, poor molding quality and low utilization of raw materials in production.

[0005] In addition, since the fluidity of the molding resin on the surface of the molding die is not necessarily good, a resin with a relatively small molecular weight is used, so the mechanical strength of the molded product is not good.

In addition, in order to improve the fluidity of the resin, it is necessary to increase the molding temperature (heating temperature), so there are disadvantages such as increased power consumption.

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