Experimental Characterization and simulative Modelling of Block Shear Fow during Mound Filling of highly filled Thermoset Injection Molding Compounds

• Applicant: Professor Dr.-Ing. Andreas Seefried
• Subject Area: Plastics Engineering
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 563322635

In the mold filling behavior of highly filled thermoset injection molding compounds, a strong wall slip occurs at the interface between the thermoset melt and the mold surface, which is not the case for thermoplastic materials. The degree of wall slip of highly filled thermoset injection molding compounds which results in block shear flow depends strongly on the amount of filler, the injection speed, the mold temperature and the surface roughness. In spite of having a strong slip between the thermoset melt and wall surface, fiber in the flow direction is still oriented under the surface of the molded parts. The thickness of the surface layer with oriented fibers decreases towards the end of the flow path and is inversely proportional to the degree of wall slip. These lead to challenges in the field of calculation, analysis and simulation of the influence of wall slip in dependence of filler content and processing conditions on the formation of fiber orientation during mold filling of highly filled thermoset injection molding compounds. Therefore, this proposal project focuses on two main scientific objectives. The first objective is the investigation and development of a method for measuring the frictional coefficient and the wall slip behavior of highly filled thermoset injection molding compounds in mold filling behavior. The second objective is to calculate, analyze and simulate the fiber orientation of the injection molded part, which depends strongly on the viscosity models and the frictional coefficients. The fiber orientation in the mold filling has a great effect on the structural properties (stress, strain and deformation) and the dimensions (shrinkage and warpage) of the final injection molded part. The expected results of this project will therefore increase the quality of the development process of complex parts made of highly filled thermoset molding compounds in the injection molding process and improve the overall comprehension of the complex processes. It helps users to shorten development cycles, predict possible mistakes and optimize their products.

• DFG Programme: Research Grants