Determination of ejection temperature and cooling time in injection molding

Estimation of cooling time for a given injection molding part is becoming increasingly important, especially when a large number of parts are produced. In order to calculate the cooling time, the ejection temperature should be known. However, to date, there is no easy way to obtain the ejection temperature even though the material selected and part thickness are known. This study uses a combination of experimental, analytical, and statistical means to establish equations for calculating ejection temperature according to material properties, part thickness, and molding conditions such as injection and mold temperatures. Therefore the cooling time of a given injection molding part can be estimated in its early design stage.