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Why Does the Injection Mold Appear Dark and Glossy?

During the production and processing of injection molds, the phenomenon of dark color and poor gloss is often encountered. So what is the reason for the dark color and poor gloss and how to solve it? In the normal injection mold production and processing process, the gloss of the mold surface is mainly determined by the type of plastic, colorant and the smoothness of the mold surface. The main reasons and solutions for the appearance of dark color and poor gloss are as follows.


1. Precautions for the use of injection molding molds


Plastic mould manufacturers in china create value in use, but also gradually lose their own value in use. Therefore, operators must attach great importance to the use of molds, and generally pay attention to the following issues.


(1) Before use, check whether there are impurities and dirt in each part of the mold. For the remaining plastic and impurities in the mold, use cotton yarn to scrub to remove, and use a copper knife to scrape off the sticky material with strong adhesion.


(2) Reasonable selection of the clamping force is based on the fact that no flash is generated when the product is formed. It cannot be assumed that the higher the better, which will increase the power consumption and easily damage the transmission parts.


(3) All transmission parts should be well lubricated, therefore, these parts must be kept lubricated.


(4) It is not allowed to hit any parts in the mold with heavy objects such as hammers, so as not to deform or even damage the China custom injection molding.


2. Analysis of the reasons for the dark gloss of the injection mold


(1) The finish of the injection mold is poor, the surface of the cavity has rust, etc., and the mold exhaust is not good.


(2) Too many recycled materials are used, the quality of plastics or colorants is poor, mixed with water vapor or other impurities, and the quality of lubricants used is poor.


(3) The gating system of the injection mold is defective, and the cold slug well should be enlarged, and the runner, the polishing main runner, the runner and the gate should be enlarged.


(4) The material temperature and mold temperature are low, if necessary, the local heating method of the gate can be used.


(5) The plastic of the plastic moulding supplies should be fully plasticized, but the degradation of the material should be prevented, the heating should be stable, and the cooling should be sufficient, especially for thick-walled ones.


(6) The clamping force should be sufficient during the manufacturing process of the injection molding mold design.


(7) The processing pressure of the injection mold is too low, the speed is too slow, the injection time is insufficient, and the back pressure is insufficient, resulting in poor compactness and a dark surface.


(8) Prevent cold material from entering the workpiece, and use self-locking springs or reduce nozzle temperature if necessary.


Doing the above 8 points can well avoid the phenomenon of dark color and poor gloss in the two shot injection molding process. Even if this phenomenon occurs in the production process, you can take good remedial measures to minimize the impact of the production progress of the enterprise and increase the production efficiency of enterprises.

Keyplast Injection Molding

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