The development of the inherent (internal) cooling stress
described in a highly comprehensible manner by Stitz's solidification model (13) is shown in Fig.
As powder is added on layer by layer, more heat is applied, which can create localized heating and cooling stresses
, leading to undesirable microstructures and, ultimately, suboptimal properties.
New Mold Deformation Analysis calculates the effects of filling pressure and cooling stresses
on the mold and the part.
The sharper the corner, the more subject it is to crack-like ruptures due to cooling stresses
or mechanical nicking, and, ultimately, failure in fatigue.
present only a part of the picture in the case of excessive wall thickness variations.
Therefore cooling stresses
contribute relatively stronger in BAPC.
Struik (7) discussed the formation of cooling stresses
in amorphous polymers and the importance of including the phase transformation as part of the simulation for the cooling induced stresses within injection molded parts.