Manufacturing of Next Generation Injection Molding Dies by Laminating Thin Sheets

本研究开发了一种制造塑料注射成型模具的新方法。在这种方法中，由于模具是由激光切割的金属薄片层合而成，与传统的模具制造方法相比，交货时间和成本都可以减少。此外，由于冷却水通道可以在模具内任意循环，因此可以实现更高的生产率和产品质量。采用扩散粘接技术对板材进行粘接，制造出了成形效率高、精度高的模具。本研究还开发了一种利用金属薄板层压模具进行塑料注射成型温度控制的新方法。在注射成型中，通常对模具进行冷却，以缩短成型周期时间。然而，从树脂流动性的角度来看，较高的模具温度在树脂填充期是可取的。因此，控制模具温度，以便在树脂填充期间加热芯，然后冷却，直到塑料部件从模具中弹出。金属板层压模具使这种加热和冷却循环，因为热水和冷水的通道可以均匀地循环在模具表面附近。采用金属薄板层压模具进行温度控制，具有成型周期快、树脂流动性好、可复制性好、注塑件精度高等优点。

This research developed a new method of making molds for injection molding of plastics. In this method, since molds are made by laminating metal sheets cut by laser, both delivery time and cost can be reduced compared with conventional die making methods. Furthermore, since channels for cooling water can be circulated arbitrarily inside the mold, higher production rate and quality of products can be achieved. Diffusion bonding was used to bond the sheets, and a mold with excellent forming efficiency and accuracy was manufactured. This research also developed a new method of temperature control for injection molding of plastics using the sheet metal laminated mold. In injection molding, the mold is normally cooled in order to shorten the forming cycle time. However, higher mold temperature is preferable during the resin filling period from the viewpoint of resin flowability. The mold temperature was thus controlled so that the core is heated during the resin filling period followed by cooling until the plastic part is ejected from the mold. The sheet metal laminated mold enables this heating and cooling cycle because channels for hot and cool water can be circulated uniformly adjacent to the mold surface. This temperature control using the sheet metal laminated mold has such advantages as high-cycle forming, improved flowability of resin, superior replicability, and high accuracy of the injection molded parts.