Vieten Tobias, Zanin Davide, Knöller Andrea, Litwin Thomas, Eberhardt Wolfgang, Zimmermann André
University of Stuttgart, Faculty for Engineering Design, Production Engineering and Automotive Engineering, Institute for Micro Integration (IFM), Allmandring 9b, 70569 Stuttgart, Germany.
Hahn-Schickard, Allmandring 9b, 70569 Stuttgart, Germany.
Micromachines (Basel). 2021 Apr 17;12(4):454. doi: 10.3390/mi12040454.
In order to economize injection molded prototypes, additive manufacturing of, e.g., curable plastics based tools, can be employed, which is known as soft tooling. However, one disadvantage of such tools is that the variothermal process, which is needed to produce polymeric parts with small features, can lead to a shorter lifespan of the tooling due to its thermally impaired material properties. Here, a novel concept is proposed, which allows to locally heat the mold cavity via induction to circumvent the thermal impairment of the tooling material. The developed fabrication process consists of additive manufacturing of the tooling, PVD coating the mold cavity with an adhesion promoting layer and a seed layer, electroplating of a ferromagnetic metal layer, and finally patterning the metal layer via laser ablation to enhance the quality and efficiency of the energy transfer as well as the longevity by geometric measures. This process chain is investigated on 2D test specimens to find suitable fabrication parameters, backed by adhesion tests as well as environmental and induction tests. The results of these investigations serve as proof of concept and form the base for the investigation of such induction layers in actual soft tooling cavities.
为了节省注塑成型原型的成本，可以采用增材制造，例如基于可固化塑料的模具，这被称为软成型。然而，这种模具的一个缺点是，生产具有微小特征的聚合物零件所需的变温工艺，由于其热损伤的材料性能，可能会导致模具寿命缩短。在此，提出了一种新颖的概念，即通过感应局部加热模具型腔，以规避模具材料的热损伤。所开发的制造工艺包括模具的增材制造、用附着力促进层和籽晶层对模具型腔进行物理气相沉积（PVD）涂层、电镀铁磁金属层，最后通过激光烧蚀对金属层进行图案化处理，以通过几何措施提高能量传输的质量和效率以及延长使用寿命。在二维测试样本上对这个工艺链进行研究，以找到合适的制造参数，并通过附着力测试以及环境和感应测试提供支持。这些研究结果作为概念验证，并为在实际软成型型腔中研究这种感应层奠定基础。
