Improvement of warpage prediction through integrative simulation approach for thermoplastic material

In the injection-molded parts, prediction of accurate warpage at initial level becomes mandatory to avoid iterative work of mold modifications. Simulation teams of many organizations are using existing commercial programs for process simulations. Material models in existing simulation technologies are having certain limitations and assumptions, which can regularly result in up to 50% variation of warpage results as compared to the actual physical warpage measurement. The commonly used Moldflow simulation model, for example, ignores temperature-dependent mechanical properties and the stress relaxation spectrum for viscoelastic materials. These assumptions affect the accuracy of the warpage prediction results significantly. To decrease these kinds of variations, BASF extended its Ultrasim® tool which is based on integrative simulation technology. Recently, a newly developed thermomechanical material model with temperature-dependent nonlinear mechanical properties and stress relaxation behavior was added in the Ultrasim. This model has been used in this work to consider the complete transient description of the warpage, which starts at packing phase of the part inside the mold, followed by actual cooling and ejection. In this article, unreinforced semicrystalline polybutylene terephthalate polymer material (Ultradur® B4520) is considered for warpage correlational study. The accuracy of the warpage prediction is compared between the integrative simulation approach, existing warpage simulation method, and the actual experimental inspection results. The result exhibits that the accuracy of the integrative simulation (Ultrasim)-based warpage simulation is relatively better than existing simulation technologies and closer to the actual measurement.

Numerical Simulation Analysis of Wood/PP Composites for Injection-Moulded Car Battery Trays

This research focused on the simulation analysis of wood polymer composites (WPCs) based on polypropylene (PP) for the injection moulding of automotive parts, namely car battery trays (CBTs). A plastic CBT, which is commonly used to support the battery in a car engine, is manufactured completely through the injection moulding process. The conventional design method is clearly unable to satisfy production requirements; however, with the application of the Moldflow software rational production process parameters, the filling time, injection pressure, clamping force, and others, can be formulated. A moulded CBT was designed using a computer-aided design tool, namely CatiaV5R20, before being imported to the finite element analysis tool, Moldflow. The use of the Moldflow software enabled a full analysis to be conducted of the material flow inside the mould cavity for the moulded CBT. Two types of gates, namely, the sprue and pinpoint gates, were used, through which the analyses were carried out by the Moldflow software to check the filling time, injection pressure, clamping force and warpage, by simulation in the sequential trials. The data on the wood fibre/PP composite, where 40 wt% of wood fibre loading was used. Finally, the use of the Moldflow simulation software was presented.

Application of Moldflow Simulation in Injection Molding of Plastic Tank

This article presents an application of moldflow simulation to optimize the injection molding process of charge air cooler plastic tank. The work shows the advantages of this kind of simulation software and information that it can provide. It also explains how big role today play simulation softwares and how they can improve product and reduce development cost.

3D Scanning Techniques Complements Predictive Engineering for Mold Flow Analysis

This study is an attempt to close the loop between simulation and reality. Many industries are of the opinion that a simulation does not really predict the actual process and is only a colorful plot for presentation. An accurate simulation can save cost by a multitude of ways like material savings, process optimization, cycle time reduction, improved quality of parts and so on. A validation of the simulation in a real time scenario will instil necessary confidence in the accuracy of the simulation study thereby closing the loop between simulation and reality In the present study, the mold flow analysis is conducted for the back plate of LED emergency light with the help of Autodesk moldflow simulation software to generate the gate location, feed system building, cooling channel wizard, fill time and to check warpage and then the result is verified by superimposing the scan data of the physical part which is scanned in Steinbichler Blue Light 3D Scanner and CAD model in Geomagic verify.

Moldflow simulation of an exposed pad leaded package

A study has been conducted for epoxy mold compound filling for a 48 lead exposed pad package. The leadframe design contains a small gap feature where it is critical to evaluate void estimates. A modeling method is being discussed to accurately predict the flow front behavior and make void percentage estimates. With improved design, void percentage significantly goes down as predicted by models. The paper contains detailed methodology for creation of CAD model with standard leadframe drawing and final analysis using a defined gate area. Fill time contours shows significant improvement comparing two designs with 35 μm and 65 μm gap feature.

Runner Balance Design of Soap Box Compounding Cavity Based on Moldflow

Filling unbalance is a critical defect for injection mould. When the upper and lower covers of soap plastic box are produced by injection mold at the same time, filling unbalance in injection would appear because of the different dimensions of the two parts. For advancing the quality of the soap plastic box, the runner system is optimized with the filling analysis module and flow runner balance module of moldflow simulation software. The three-dimensional geometrical models of the two covers are constructed using Pro/e software. In moldflow the runner balance optimization of the soap box compounding cavity is analysis. The results indicate the optimized cross section of the runners can reduce the flow unbalance ratio from 3.38% to 0.73%, and the filling time and pressure can satisfy the demands. According to the analysis results moldflow is appropriate for runner balance design of the plastic products.