Sigma Plastic Services, Inc. recently presented Sigmasoft - The Virtual Process and Mold Development software designed for injection molding processes at the NPE 2012, North/South Hall, Booth 65027 including the latest functionality improvements of Sigmasoft. As a standard practice, simulation tools are used during the development of injection molded parts. These simulation tools, which are based on empirical values and mathematical models, predict the filling of the mold, the post-pressure and cooling stages up to the ejection of the part, as well as the final deformation of the part. However, accurate and reliable simulations can only be achieved if, besides the CAD geometries, all relevant factors such as mold, hot runner systems and process parameters are integrated into the simulation with all required physical data.
The high level of complexity required during modeling and the simplifications that are apparent in conventional injection molding simulation software are not able to achieve this integration. However, the "Finite-Volume-Method" used by Sigmasoft makes it possible to easily and quickly integrate all available geometry and process-related information at every stage during the product development cycle. The meshing of the simulation model is completely automatic and does not require additional rework, a unique feature which offers a clear advantage in productivity and expands the benefits of process simulation from the part design engineer to the quality-responsible personnel in production. Never before has this been possible.
With the CAD files loaded and automatic mesh generated, the process is defined to incorporate the actual production process values. Subsequently, a single-cycle thermal analysis of the part and mold is conducted to identify hot and cold spots in the part and mold. Part orientation and cooling line location and temperature are all optimized to minimize the cycle time while reducing thermal gradients which negatively influence part distortion. Consequently, it is possible to evaluate the efficiency of the tempering system based on the energy consumption. Furthermore it is possible to predict the correct ejection forces and the influence of post-molding tempering processes, such as painting, galvanization, or annealing on the stress distribution on the part and the resulting dimensional stability. Removal of part material during machining operations and the redistribution of stresses can also be considered.
The injection molding simulation with Sigmasoft is therefore not limited to the evaluation of part designs, but can also support all subsequent development phases with detailed information. Sigmasoft is used throughout the complete process to make critical decisions about part and mold design, preproduction sampling, identification of processing windows and production trouble-shooting.