High precision micro components by the use of dynamically tempered injection molding

该项目的目的是研究非晶热塑性塑料的时间-温度-压力条件，以实现具有最佳表面形状和最小化方向和残余应力的微型部件，同时在整个部件几何形状上实现最高可能的尺寸精度。这种新型工艺组合——动态回火注射冲压，结合了动态回火注射成型工艺和注射冲压工艺的优点。动态回火注射成型允许高表面长宽比，而注射冲压允许最高的尺寸稳定性在整个结构长度。在应用方面，其目标是优化表面复制、尺寸稳定性以及最小化残余应力和定向，同时考虑到经济周期时间。该研究项目的基础是了解动态回火注塑成型和注塑冲压工艺的各种工艺特性。在传统的动态回火注塑成型的情况下，体积收缩是由在保压阶段发生的熔体注射来补偿的，由于流动路径上的压力分布不均匀，导致尺寸公差有限。注射冲压通常在低于材料玻璃化转变温度的温度下进行。由于靠近零件边缘的快速凝固，这限制了精细表面结构的形成。通过结合两种制造工艺，这两种工艺的优势不仅可以协同用于动态回火注塑冲压，而且通过使用与工艺相关的材料参数和与温度和压力相关的工艺模拟，可以最大限度地利用部件性能。

The aim of the project is the investigation of the time-temperature-pressure conditions for amorphous thermoplastics for the realization of micro components with optimal surface shaping and minimized orientations and residual stresses, while achieving the highest possible dimensional accuracy over the entire component geometry at the same time. The novel process combination, the dynamically tempered injection stamping, combines the advantages of the dynamically tempered injection molding process and injection stamping. Dynamically tempered injection molding allows high surface aspect ratios while injection stamping allows highest dimensional stability over the entire constructional length. On the application side, it is the aim to optimize surface replication, the dimensional stability as well as to minimize residual stresses and orientations taking into account an economic cycle time.Basis of the research project is the knowledge about the various process-specific properties of the dynamically tempered injection molding and the injection stamping process. In the case of conventional dynamically tempered injection molding, volume shrinkage is compensated by melt injection taking place during the holding-pressure phase, resulting in limited dimensional tolerances due to inhomogeneous pressure distributions over the flow path. Injection stamping normally takes place at temperatures below the glass transition temperature of the material. Because of the fast solidification close to the edge of the part, this results in limitations in the shaping of fine surface structures. By combining both manufacturing processes, the advantages of the processes are not only to be used synergistically for the dynamically tempered injection stamping, but by means of the use of process-relevant material parameters and a temperature- and pressure-dependent process simulation, a maximum utilization of the component properties is to be achieved.