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 Article Title 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.

In situ flow state characterization of molten resin at the inner mold in injection molding

“…Injection molding is demonstrated to be the most efficient way to fabricate components with complex shapes and high-quality surface features. 19,20 The polymer compound that can be used as a raw material for processing plastic products is called a resin. Polypropylene (PP), polycarbonate (PC), nylon (NYLON), polyether ether ketone (PEEK), and polyether sulfone (PES) are the most common resins used in injection molding, with strong plasticity, good decoration, and durability, and widely used in the aerospace field, optical and optoelectronic field, automotive industry, medicine, and so on.…”

“…Furthermore, the structure of the channel and the development of the quasi-two-dimensional model in the injection molding process make it possible for the in situ viscosity to be identified. By introducing pressure sensors, displacement sensors, or/and temperature sensors 20,23 for measuring polymer melt behavior, some works have been done successfully by using dies embedded into either the barrel/nozzle (plasticizing process) or mold (filling process) to test the material rheology. 24,25 The detection of in situ viscosity in a plasticizing unit can monitor the melt flow behavior, investigate the quality of components, and further suppress process fluctuations.…”

“…Injection molding is demonstrated to be the most efficient way to fabricate components with complex shapes and high‐quality surface features 19,20 . The polymer compound that can be used as a raw material for processing plastic products is called a resin.…”