Causes and Measures of Bubble in Injection Molding
- Author:liuweiqiong
- Source:liuweiqiong
- Release on:2017-10-25
The mold is mainly the tool for the development of the workpiece, the injection molding process in the workpiece, we will find some bubbles in the formation of injection molding bubbles easily lead to workpiece melting marks, and lead to the phenomenon of the reasons As well as the settlement measures, the Chinese standard parts network for a detailed introduction.
As a result, when the wall thickness of the product is large, the outer surface cooling rate is faster than that of the central portion. Therefore, as the cooling progresses, the resin at the center portion expands toward the surface and causes the filling of the central portion to be insufficient. This is called vacuum bubbles.
The main measures are:
1, according to the wall thickness, to determine a reasonable gate, runner size. General gate height should be 50% to 60% of the wall thickness of the product.
2, to the gate seal so far, leaving a certain amount of injection material injection.
3, the injection time should be slightly longer than the gate sealing time.
4, reduce the injection speed, increase the injection pressure.
5, the use of high melt viscosity grade material.
Cause two: due to the generation of volatile gases caused by the bubble.
The main measures are:
1, fully pre-drying.
2, reduce the resin temperature, to avoid decomposition of gas.
3, poor mobility caused by the bubble, can improve the temperature of the resin and mold, to improve the injection rate to be resolved.
As a result, when the wall thickness of the product is large, the outer surface cooling rate is faster than that of the central portion. Therefore, as the cooling progresses, the resin at the center portion expands toward the surface and causes the filling of the central portion to be insufficient. This is called vacuum bubbles.
The main measures are:
1, according to the wall thickness, to determine a reasonable gate, runner size. General gate height should be 50% to 60% of the wall thickness of the product.
2, to the gate seal so far, leaving a certain amount of injection material injection.
3, the injection time should be slightly longer than the gate sealing time.
4, reduce the injection speed, increase the injection pressure.
5, the use of high melt viscosity grade material.
Cause two: due to the generation of volatile gases caused by the bubble.
The main measures are:
1, fully pre-drying.
2, reduce the resin temperature, to avoid decomposition of gas.
3, poor mobility caused by the bubble, can improve the temperature of the resin and mold, to improve the injection rate to be resolved.