The constant/variable kinematics adjustment of the crosshead and the mold’s stability management in injection molding

Abstract During the clamping process in an injection-molding machine, the mold’s movement is directly driven by the velocity of the crosshead. The form of the adjustment on the crosshead’s kinematics can influence the final dynamics of the mold, which can contribute to the stability of the clamping duration further. This article is aimed at investigating the kinematics analysis and the stability management strategy of the mold in the early design stage for the clamping mechanism. The two different velocity-controlled forms of the crosshead, constant and variable kinematics adjustments, are applied and compared in the clamping analysis. Three factors of the crosshead, the maximum velocity, the acceleration/deceleration stage adjustment, and the multi acceleration/deceleration process, are validated for the stability control of the mold’s motion in the injection molding process. The results show an extra “fast” process is detected in the constant condition when compared to the variable crosshead’s kinematics adjustment. Furthermore, by the reasonable adjustment of the maximum velocity and two special positions of the crosshead during the acceleration and deceleration stages, the maximum acceleration fluctuation of the mold is decreased by more than 50%, allowing the mold to move more steadily.