PRODUCTION PROBLEMS AND SOLUTIONS(4)

Bubbles

In the production process of injection molded parts, when the plastic melt fills the cavity, the cavities of the multi-strand melt front wrapping stroke or the melt filling end can not be discharged due to the gas being wrapped by the melt, and the result is the formation of bubbles on the plastic part.
Therefore, the improvement measures for this defect are as follows

Increase back pressure or reduce material temperature

Fully dry the ingredients

Reduce screw speed or injection speed

Increase or enlarge the exhaust groove to improve the exhaust effect

Reduce the amount of molten material remaining in the barrel

Reduce the gate size or change the gate shape to allow gas to stay in the runner

Use plastic or toner with better thermal stability

Reduce the temperature of the unloading section and improve the degassing situation

Expand

In the production process of injection molded parts, after the product is demolded, the local volume becomes larger and swells in some specific positions. The bulging of the plastic part is because the plastic that has not completely cooled and hardened releases gas under the action of internal pressure, which causes the plastic part to expand.
Therefore, the improvement measures for this defect are as follows

Effective cooling. The method is to reduce the mold temperature, extend the mold opening time, and reduce the drying and plasticizing temperature of the plastic