As there is often a certain deviation between actual process conditions and the ideal conditions

after shaping the product there are usually some unavoidable defects

and the residual stress is the most common one. Residual stresses of injection products are the still remained inner stresses even though the outer restrictions have been removed

easily causing warpage

deformation or even crack that will mainly do harm to the parts in many cases when the products get used. So it is important to pay attention to the influence of residual stresses when designing plastic products. This article is mainly to give a relatively detailed introduction to residual stresses

surrounding by their generating

measuring

and decreasing as well as computer simulating.