Numerische Simulation und experimentelle Validierung der Temperatur- und Druckverhältnisse eines mehrkanaligen Thermoplastdruckkopfes

Abstract

Fused Deposition Modeling has been in constant development since its launch in 1991 by Stratasys and represents a key technology in additive manufacturing today. High process stability is needed to apply this technology on an industrial scale. However, understanding of the complex extrusion process in the extrusion process is limited. As a result, within this work, heat transfer and flow simulations are performed on a newly developed multimaterial printhead to predict the temperature and pressure distribution inside the printing head as a function of critical process parameters. The printhead is capable of processing continuous carbon fiber rovings and up to three thermoplastic filaments. The simulations are calibrated and validated by means of experimental tests in order to provide a realistic insight into the temperature and pressure distribution within the printhead. On this basis, key process parame-ters, such as the feed rate of the filament, in relation to the flow behavior of the thermoplastic melt and the resulting pressure distribution in the printhead are analyzed and evaluated. In addition, the influence of the process parameters on the impregnation of the carbon fiber roving is shown. Subsequently, the influence of alternative materials on the temperature distribution inside the print head is examined within a design analysis. In addition, geometric and thermal changes are made to the nozzle to discuss the effect on pressure distribution in the printhead.