What are the basic methods to solve the shrinkage defect of flat plastic parts？
Flat injection parts have a large surface that is easy to cause shrinkage problems, and the reason is the molecular orientation of large-scale injection products is serious. Coupled with improper cooling of the mold, the shrinkage rate of each part of the injection molded part will be different, which will further cause the deformation and distortion of the plastic products.
The deformation of big flat products has always been one of the problems in the injection molding industry. Based on long-term experience accumulation, injection mold engineers have summarized some effective methods to ease these defects.
1. Adjust the mold structure to a multi-point waterway(three-plate mold), and it can reduce the degree of molecular orientation and reduce the gap of inconsistent shrinkage.
2. Properly increase the mold temperature, such as ABS molding, the mold temperature should keep at 60℃ above. The purpose is to reduce the cooling time of the products and reduce the deformation phenomenon caused by the excessive temperature difference and reduce the degree of molecular orientation.
3. Reduce shrinkage and effectively improve product quality by increase the injection or holding pressure and extend the injection and holding time. Extending the period of injection and holding is currently the best way to solve the deformation defect.
4. If the above three methods are not available, you can consider a related jig to shape the product into the actual dimensions.
