Manufacturing of Next Generation Injection Molding Dies by Laminating Thin Sheets

本研究开发了一种新的塑料注射成型模具制造方法。在该方法中，由于通过层压由激光切割的金属板来制造模具，因此与传统的模具制造方法相比，可以减少交付时间和成本。此外，由于冷却水的通道可以在模具内任意循环，所以可以实现更高的生产率和产品质量。使用扩散接合来接合片材，并且制造具有优异成形效率和精度的模具。本研究也发展出一种新的塑胶射出成型温度控制方法。在注塑成型中，模具通常被冷却，以缩短成型周期时间。然而，从树脂流动性的观点出发，在树脂填充期间，较高的模具温度是优选的。因此，控制模具温度，使得在树脂填充期间加热型芯，然后冷却，直到塑料部件从模具中排出。金属板层压模具能够实现这种加热和冷却循环，因为用于热水和冷水的通道可以在模具表面附近均匀地循环。这种使用金属薄板叠层模具的温度控制具有这样的优点，例如高循环成形、改善的树脂流动性、上级可复制性和注射模制部件的高精度。

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.