Due to special functions, some thick-walled transparent injection parts are often encountered during injection molding. Because to performance reasons, these plastic parts use PC as the raw material, and the average wall thickness More than 6mm, the maximum wall thickness exceeds 12mm. For such plastic parts, two problems often occur during injection molding, one is the shrinkage of the appearance of the product, and the second is the occurrence of bubbles in the product. Because of the thicker wall, deformation is not the main problem.
1, Appearance shrinkage: The main reason is that the wall thickness is too thick and the product shrinks greatly. During this shrinking process, more melt must be replenished to prevent shrinkage, and a higher mold temperature is required to shrink the product as a whole (opaque products need to reduce the mold temperature without worrying about vacuum bubbles).
The measures to solve the appearance shrinkage are as follows:
- Increase the number of gates on the mold and increase the volume of the cold cavity;
- Slow down the injection speed, increase the back pressure and barrel temperature, increase the holding pressure and time, extend the cooling time, and increase the mold temperature.
2, Bubbles appear in the product: There are two reasons for the bubbles, one is the gas in the melt, and the other is the vacuum bubble generated by the shrinkage. Most of the gas in the melt is generated by the decomposition of air and a small amount of plastic. The solution is to fully dry the raw materials; while the vacuum bubble is a bit more tricky, it needs a mold and molding process to work together. The solution is the same asshrinkage.
To learn more about our manufacturing capabilities and discover what makes us different, please visit our website. If you’re ready to jump into your next project with us. No matter your need, contact us now and we not only meet your requirements, but we actively look for ways to improve on your product and thus save you money and time in today’s competitive marketplace.