Volumetric shrinkage result shows the distribution of part volume change percentage as the part is cooled from high temperature and high pressure at current time step to ambient temperature and ambient pressure. This calculation is based on PVT relationship of the plastic material.
Positive value represents volume shrinkage while negative value represents volume expansion. In optimized condition, uniform volumetric shrinkage is desired.
You should focus on the uniformity rather than the magnitude of the volumetric shrinkage.
Non-uniform volumetric shrinkage is caused by two reasons:
•Non-uniform pressure distribution.
•Non-uniform temperature distribution.
Non-uniform volumetric shrinkage can lead to two results:
•Warpage after the part is ejected.
•Thermal induced residual stress if the stress did not transform into deformation.