1. The thickness of each part of the product is different
2. The internal pressure of the mold is insufficient
3. Insufficient cooling of mold
4. Deformation due to insufficient cooling time
In the process of producing products, dents are the most frequent undesirable phenomena. When the plastic injected into the household product mould is cooled, it shrinks in volume. The early cooling part, that is, the surface hardens first, and bubbles will be generated inside. The so-called dents mean that the slow cooling part produces a conspicuous concave surface in the direction of bubble contraction.
Materials with large shrinkage are also prone to dents. When changing molding conditions to eliminate dents, the setting conditions should be set in the direction of small shrinkage. That is, the mold temperature and barrel temperature decrease, and the injection pressure increases, but it should be noted that residual internal... less
