On the influence of mold temperature during dynamic temperature-controlled injection molding of semi-crystalline micro- and thin-walled components
The micro- and thin-wall injection molding process is one of the most important manufacturing processes for the production of small-sized semi-crystalline components. In some cases, the use of dynamic mold temperature control has been established, which leads to a reduction in the material cooling behavior due to an increased mold temperature during the injection phase. In addition to a better molding of fine structures, it is known that influencing internal properties and, therefore, resulting component properties is possible. There are currently various limitations for understanding the properties of small-sized semi-crystalline components. On the one hand, there is no detailed knowledge of the process-based crystallization behavior with high cooling conditions and isothermal holding steps during cooling, which complicates the process parameter design and the interpretation of resulting component properties, which are influenced by the crystallization process. On the other hand, existing knowledge of injection-molded components is mainly limited to local component positions, although it cannot be assumed that there is a homogenous component behavior over the entire component geometry. In the context of this work, the influence of the mold temperature in the dynamically tempered injection molding process on the process-based crystallization behavior as well as on the formation of internal properties and physical component properties will be investigated using PA12. For this purpose, the thermally induced crystallization behavior at a process-based temperature profile is investigated analytically and experimentally. Furthermore, thin-walled plates are injection-molded by means of dynamic temperature control with variation of the mold temperature conditions and characterized in terms of their internal properties and physical component properties. With the help of this knowledge, the basis for the production of semi-crystalline thin-walled components with a defined property profile and high component performance is to be created.