Abstract: This paper provide a nonlinear mathematical model for the prediction of shrinkage of thin-well plastic cylindrical parts based on design of experiments（DOE）.Four most influential parameters were screened by using fractional factorial design（FFD）：mold temperature, pack time, pack press, and melt temperature. For the four principal processing parameters, a mathematical model was formulated by using central composite design（CCD）of experiments and FE simulation. Finally, the results of statistical analysis were collected from software Moldflow, and engineering tests ware also used. The results suggested that the mathematical model could be used to predict shrinkage with reasonable accuracy.

Key words: cylindrical thin-walled part, injection molding, fractional factorial design, central composite design, shrinkage