K 2019 attendees interested in optimizing extrusion processes should make plans to visit the Sigma Engineering stand (B 31 in hall 13). The company based in Aachen, Germany, will share with visitors initial insights on adapting its Sigmasoft Virtual Molding simulation technology to extrusion dies.
Non-homogenous velocity distribution on melt results in deformation of extrudate.
Melt behavior inside an extrusion die is comparable to flow behavior inside a thermoplastic hot runner or elastomer cold runner, according to Sigma. In an extrusion die, internal temperature distribution as well as flow channel geometry also have a significant influence on flow behavior. Having managed countless thermoplastic and elastomer application projects over the years, Sigma said that it can rely on broad experience in the thermal and geometrical balancing of hot and cold runner systems. Applying its expertise to extrusion applications is a logical next step, added the company.
Simulation helps to identify dead spots, excessive dwelling time in the die and high pressure losses before the die is built. This reduces tool changing costs and trial-and-error runs to determine the optimal configuration.
First tests of the simulation software in extrusion applications reportedly show that SigmaSoft technology automatically optimizes flow channels in the extrusion die within hours and, thus, improves the quality of the extrudate. The software defines geometrical degrees of freedom for the extrusion die’s flow channels and then autonomously determines the ideal geometry for a dimensionally stable extrudate.
“Software currently on the market helps to calculate temperature distribution inside the extrusion dies,” said Chief Technical Officer Timo Gebauer. “However, with the help of our software and the included Virtual DoE, users will be able to automatically optimize their extrusion die, finding a geometry that allows for an extrusion with homogenous velocities." The optimized velocity profile in the extrusion die minimizes deformation of the extruded profile, Gebauer added.