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#077 Solutions for Molding Defects (Gloss Defect)

Category : Molding Defect Countermeasures
April22, 2011

Although it is ideal that the surface of the molded product is a copy of the surface of the cavity and has a beautiful shape and gloss, some times the surface gloss may become clouded, or there may be variations in the gloss.

Particularly in the case of products with decorative surfaces in which the external appearance quality is very important, gloss defect can become a very serious defect.

The following methods can be thought of as the countermeasures for solving the problem of gloss defects.

(1) Countermeasures related to molds

1. There are no air vents or they are insufficient.
2. The gate is small.
3. The sprue and runners are thin.
4. The electroplating condition of the cavity surface is not good.
5. The polishing condition of the cavity surface is not good.
6. There are some deposits (soot) adhered to the cavity surface.

(2) Countermeasures related to the injection molding conditions

1. The charge quantity is insufficient.
2. The cushion position is too short
3. The holding pressure is too low.
4. The pressure holding time is too short.
5. The cavity surface temperature is low.
6. The preliminary drying of the molding material is insufficient.

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