András Suplicz

Thermally conductive polymer compounds for injection moulding: The synergetic effect of hexagonal boron-nitride and talc

The aim of the research project was to investigate and maximize the thermal conductivity of polymer compounds with low filler content (<30 vol%). The study focused on the effect of the matrix material, the filler type, the processing method and the interaction of the fillers. It was concluded that compression-moulded samples have higher thermal conductivity than injection-moulded samples due to the segregation effect and the orientation of the anisotropic fillers. Conductivity can be improved by adding fillers with higher thermal conductivity, and also by combining, or hybridizing the fillers. A synergetic behaviour between hexagonal boron-nitride and talc which improved thermal conductivity was found.

Development of Thermally Conductive Polymer Materials and their Investigation

In the recent years a remarkable development can be observed in the electronics. New products of electronic industry generate more and more heat. To dissipate this heat, thermally conductive polymers offer new possibilities. The goal of this work was to develop a novel polymer based material, which has a good thermal conduction. The main purpose during the development was that this material can be processed easily with injection molding. To eliminate the weaknesses of the traditional conductive composites low-melting-point alloy was applied as filler. Furthermore in this work the effect of the filler content on thermal conductivity, on structure and on mechanical properties was investigated.

Enhanced Injection Molding Simulation of Advanced Injection Molds

The most time-consuming phase of the injection molding cycle is cooling. Cooling efficiency can be enhanced with the application of conformal cooling systems or high thermal conductivity copper molds. The conformal cooling channels are placed along the geometry of the injection-molded product, and thus they can extract more heat and heat removal is more uniform than in the case of conventional cooling systems. In the case of copper mold inserts, cooling channels are made by drilling and heat removal is facilitated by the high thermal conductivity coefficient of copper, which is several times that of steel. Designing optimal cooling systems is a complex process; a proper design requires injection molding simulations, but the accuracy of calculations depends on how precise the input parameters and boundary conditions are. In this study, three cooling circuit designs and three mold materials (Ampcoloy 940, 1.2311 (P20) steel, and MS1 steel) were used and compared using numerical methods. The effect of different mold designs and materials on cooling efficiency were examined using calculated and measured results. The simulation model was adjusted to the measurement results by considering the joint gap between the mold inserts.