Liao Yi-Ling, Tsai Hsi-Hsun
Department of Mechanical Engineering, Ming Chi University of Technology, New Taipei City 24301, Taiwan.
Polymers (Basel). 2022 Apr 18;14(8):1631. doi: 10.3390/polym14081631.
Many challenges are associated with the injection molding process for forming a rib-structured pallet (1100 mm × 1100 mm × 140 mm, length × width × height) because greater flowing resistance through the rib channels within the pallet can induce insufficient filling. Essentially, multi-gate filling involves a sequential valve gate system, which helps to spread the filling front with fewer weld lines. Based on the presetting of the sequential scheme of the valve gates, actual measurements of pallet flatness using the ATOS scan system were compared to numerical warpage measurements of a pallet derived by Moldex3D 2020. In this study, we propose a sequential scheme by actuating the valve gates to open once the flow front spreads towards them; then, actual warpage measurements of a pallet are compared with numerical measurements. The results show that the warpage of the top surface of the pallet is 5.144 mm in actual measurements and 5.729 mm in simulation. The results all indicated small warpage with respect to the pallet size. The simulation and actual measurements of flatness are in excellent agreement; the difference in top flatness between the simulated and actual pallet is 0.59 mm, while the bottom flatness difference is 0.035 mm. By adjusting the cooling water temperature, increasing the mold temperature, and decreasing the material temperature, overall flatness and warpage displacement can be reduced.
对于成型肋结构托盘（1100毫米×1100毫米×140毫米，长×宽×高）的注塑成型工艺而言，存在诸多挑战，因为托盘内肋通道的流动阻力较大，可能导致填充不足。本质上，多浇口填充涉及一个顺序阀浇口系统，这有助于使填充前沿展开，减少熔接线。基于阀浇口顺序方案的预设，使用ATOS扫描系统对托盘平整度进行的实际测量结果与通过Moldex3D 2020得出的托盘数值翘曲测量结果进行了比较。在本研究中，我们提出了一种顺序方案，即一旦流动前沿向阀浇口蔓延，就驱动阀浇口打开；然后，将托盘的实际翘曲测量结果与数值测量结果进行比较。结果表明，托盘顶面的实际翘曲为5.144毫米，模拟翘曲为5.729毫米。所有结果均表明，相对于托盘尺寸而言，翘曲较小。平整度的模拟结果与实际测量结果高度吻合；模拟托盘与实际托盘的顶面平整度差异为0.59毫米，底面平整度差异为0.035毫米。通过调节冷却水温度、提高模具温度和降低材料温度，可以降低整体平整度和翘曲位移。
