Causes and solutions of bubbles in injection molding

In the process of injection molding, bubble is a very common phenomenon, light is harmless, heavy directly affects the actual quality of injection molding products.


1、 Causes of bubbles in injection molding

In the process of injection molding, when the wall thickness of the product is large, the cooling speed of the outer surface is faster than that of the central part. Therefore, with the cooling process, the resin in the central part shrinks and expands to the surface, resulting in insufficient filling in the central part, which is called vacuum bubble.

2、 The main solutions to bubbles in injection molding are as follows:

1. According to the wall thickness, determine the reasonable gate, runner size. Generally, the gate height should be 50% ~ 60% of the wall thickness of the product.

2. Until the gate is sealed, there is a certain amount of supplementary injection material.

3. The injection time should be slightly longer than the gate sealing time.

4. Reduce the injection speed and increase the injection pressure,

5. The material with high melt viscosity grade is adopted.

6. The main solutions are as follows

7. Fully pre dry.

8. Reduce the temperature of resin to avoid decomposition gas.

9. The bubbles caused by poor fluidity can be solved by increasing the temperature of resin and mold and increasing the injection speed.


About JasonMould Industrial Company Limited

Jasonmould is a China mold maker of plastic molds- injection mold, die casting moulds, plastic blow molding, rotational molding, medical plastic injection molding, two shot plastic injection molding, insert molding, overmolding, metal injection molding, micro injection molding, powder injection molding, ceramic injection molding, liquid injection molding, husky injection molding, household mold, casting mold, die mold tool, custom molds, china moulds, rapid prototyping tooling, plastic prototyping tooling, punch press tooling, die and tooling for mobile/ cell phone parts, automotive parts, vacuum cleaners, rechargeable tools, telephones, copiers, computers, multimedia speakers, and many other electronic products and household appliances. And also a plastic product manufacturer, mold manufacturer China– plastic parts, plastic water tank, plastic balls, plastic containers, plastic buckle, plastic anchor, plastic hanger, plastic spoon, plastic pipe fitting, plastic tumble, plastic tableware, plastic cups, plastic bottles, plastic tray, plastic cosmetic container, plastic case, plastic food container, plastic chairs, plastic caps, plastic cap closure, plastic tubes, plastic water pipes, plastic knobs, plastic tubing, plastic utility boxes, plastic racks and so on.

Person: James Yuan
Company: JasonMould Industrial Company Limited
Add:  LongGang Village,LongXi Town,BoLuo County,HuiZhou City,GuangDong Province, China
Tel: 86-752-6682869
Email: [email protected]


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