Prior to the injection of the molten plastic into the mold, the two halves of the mold must first be securely closed by the clamping unit. When the mold is attached to the injection molding machine, each half is fixed to a large plate, called a platen.
The front half of the mold, called the mold cavity, is mounted to a stationary platen and aligns with the nozzle of the injection unit. The rear half of the mold, called the mold core, is mounted to a movable platen, which slides along the tie bars.
The hydraulically powered clamping motor actuates clamping bars that push the moveable platen towards the stationary platen and exert sufficient force to keep the mold securely closed while the material is injected and subsequently cools. After the required cooling time, the mold is then opened by the clamping motor. An ejection system, which is attached to the rear half of the mold, is actuated by the ejector bar and pushes the solidified part out of the open cavity.
The clamping mechanism is one of the most critical factors when producing high-quality products through injection molding. In fact, the clamping mechanism of the five-point double-toggle is more commonly used in high-speed plastics injection molding machines.
Multi-body dynamics analysis, this research aims to improve the performance of a five-point double-toggle clamping mechanism. This work also provides instructions and a clear knowledge for developing the clamping system in an injection molding machine that may apply various clamping forces.
According to this investigation, the theoretical calculation was addressed first, followed by the validation of the computational model. In addition, clamping forces affect the primary dimensions, such as the thickness of the movable and fixed plate, the diameter of the tie-bar, and the average cross-section of the link, which have been explored theoretically and numerically.
Moreover, according to the findings, the ideal design makes achieving a high force amplified ratio possible. The resulting mechanism has good kinematic performance and operates stably with reduced energy consumption and a cheaper cost than the preliminary design.
Additionally, the results reveal that the optimal design allows for a higher force-amplified ratio. In addition, the work has discovered the correlations between the various parameters, such as the ratio of force amplification, the critical angles of the double-toggle clamping mechanism, and the stroke of the moveable mold.
The enhanced parameters will generate relevant knowledge that individuals can apply in designing and manufacturing the clamping mechanism of the microinjection molding machine.