Thermoforming of thermally conductive plastics with multimodal fillers

在热成型中，扁平半成品被成形成三维部件。通常，热成型用于生产包装物品或大面积技术部件。在技术部件的生产中，它经常与注塑成型竞争。热成型的优点是能够生产特别大面积的零件，可以达到最小的壁厚和表面质量，以及机器和模具的低投资成本。然而，热成型的低投资成本被组件性能对平板半成品的加工性能的增加的依赖所抵消。用于热成型的新材料的开发也可以打开以前未开发的应用可能性。然而，随着热成型材料功能化程度的提高，例如通过添加添加剂，成型行为的复杂性也增加了。目前，较高的填料含量和不同的填料组合对热成形性能的影响，以及热成形对所得填料取向和部件导热系数的影响还没有深入的研究。在本研究项目中，使用多模填充热成型半成品的目的是进一步提高导热系数，同时确保良好的加工性。通过这种方式，可以通过巧妙地选择填料成分来开发定制的热成型半成品。不同的填料几何形状组合在一起，通过它们的相互作用，对材料性能产生积极影响。例如，不同的颗粒大小有利于热传导路径的形成，因此较小的颗粒可以在较大的颗粒之间沉降并建立额外的接触。然而，在多填料系统中，可能会发生其他相互作用，需要更详细地描述。特别是，在热成型过程中，填料的相互作用及其对成型的影响还没有被研究过。

In thermoforming, flat semi-finished products are formed into three-dimensional components. Typically, thermoforming is used for the production of packaging articles or large-area technical components. In the production of technical components, it often competes with injection molding. The advantages of thermoforming are the ability to produce particularly large-area components, the minimum wall thickness and surface quality that can be achieved, and the low investment costs for machine and mold. However, the low investment costs for thermoforming are offset by an in-creased dependence of the component properties on the processing properties of the flat semi-finished products. The development of new materials for thermoforming can also open up previous-ly untapped application possibilities. However, as the functionalization of thermoforming materials increases, for example through the addition of additives, the complexity of the forming behavior also increases. Currently, the influence of high filler contents and different filler combinations on thermoformability and the influence of thermoforming on the resulting filler orientation and thus the thermal conductivity of the components have not yet been researched in depth. Within this research project, the use of multimodal filled thermoforming semifinished products is intended to further increase the thermal conductivity while at the same time ensuring good processability. In this way, customized thermoforming semifinished products can be developed by a clever choice of filler composition. The different filler geometries are combined and, through their interaction, positively influence the material properties. For example, the formation of heat conduction paths is favored by different particle sizes, so that smaller particles can settle between larger ones and establish additional contact. In multi-filler systems, however, other interactions can occur which need to be described in more detail. In particular, the filler interaction and its effect on forming in the thermoforming process has not yet been investigated.