The importance of precise boundary conditions for the simulation of micro-injection molding
The filling process of a micro spiral was simulated by considering the pressure dependency of the viscosity and using adjusted heat transfer coefficients. The later one was determined by reverse engineering based on the relationship between the injection pressure and the filling degree obtained by producing short shots on an accurately controlled micro-injection molding machine. It can be shown that the actual flow rate of the melt in a micro cavity of high aspect ratio can be substantially influenced by the degree of the melt compressibility in the barrel of the plastification unit. Moreover, with different cavity thicknesses and processing conditions the heat transfer coefficient between the polymer and the mold wall varies over a wide range, even during the filling stage, which could be an indication for the dependence of the heat transfer coefficient on the cavity pressure.
pdf-file, 25 Pages, 1.1 MB
The Journal of Plastics Technology is a peer reviewed internet periodical published under the auspices of the Scientific Alliance of Polymer Technology (WAK)
International Polymer Processing, the journal of the Polymer Processing Society, is a discussion forum for the world-wide community of engineers and scientists in the field of polymer processing.
The journal covers research and industrial application in the very specific areas of designing polymer products, processes, processing machinery and equipment.
The Journal of Plastics Technology is indexed in SCOPUS, the largest abstract and citation database of peer-reviewed literature.