13. CONNECT! Online

Moldflow Solver Research and Development Update

Franco Costa leads the Moldflow Solver Development Team. In this presentation, he will review recent work on improving the accuracy of predictions in the Moldflow solvers, particularly in the area of warp deflection predictions for 3D geometries, as well  as outline new features and capabilities being developed such as a new prediction of burn mark visual defects and the elimination of model size limits for 3D Warp analyses. A brief overview will also be given of ongoing external research collaborations.

If I only had known this before

When we talk to customers, we very often get asked for things that may have been in the software for a few years. We also see people using workflows that are based on state of the art 10 years ago and that can be hugely improved. During this presentation I will highlight a number of workflows and features that were introduced over the last years that may have been overlooked and you may not have benefitted from.

I will also give you a very early view into a new Fusion integration that is being developed and that we expect to make available in a Preview form towards the end of the summer. The intent here is not build a direct re-implementation of the products we’ve used for the last 20 years, but to build up functionality based on the current state of technology, and make it smarter. A lot of this is from the ground up foundational work that will allow us to address very costly, common and pervasive industry problems.

Challenges in the simulation of highly filled plastics for thick-walled components

The simulation of the processing of filled resins, e.g. glass-fibre reinforced polymers, is an absolute standard in the plastics industry. Despite the high penetration in the market as well as the continuous development of simulation methods, there are still fields in which the prediction accuracy of the known models does not reach the usual high quality. In the case of highly filled materials (filling levels above 40 %) in combination with thick-walled components, effects occur that still are challenging for the standard simulation methods today. This lecture will briefly discuss the effects of highly filled plastics in thick-walled components using an example and name possible methods for increasing the prediction quality.

Improvement in warpage prediction results through integrative simulation with Moldflow & Ultrasim^®

For plastic parts that are manufactured by injection molding process, it is mandatory nowadays to predict accurate warpage at a preliminary stage. However, the existing process simulation method with Moldlfow has some limitations and is based on several simplified assumptions, e.g. it ignores temperature dependent mechanical properties. To compensate for these limitations, BASF has introduced a new module for its Ultrasim^® tool which is based on an integrative simulation technology, using first Moldflow results for the filling and packing phase but then map those onto a FEM model using a more complex material model to simulate the cooling and shrinkage phase. This thermo-mechanical material model has been carefully developed by considering temperature dependent, non-linear mechanical properties and stress relaxation behavior. The model also considers time dependent description of the warpage starting from packing phase of the molding process, followed by actual cooling and ejection. In this study, Polybutylene terephthalate (PBT) polymer (unfilled – Ultradur® B4520 and 30% glass filled – Ultradur® B4300G6) and Polyamide (Ultramid® A3WG10 which is 50 % glass filled) materials have been considered for warpage correlation study. The accuracy of the prediction has been compared between the classical simulation approach with Moldflow, the new Ultrasim^®  approach and the actual experimental inspection results.

Virtual process signals for process monitoring in injection molding

Within the environment of process monitoring using AI/ML based methods, data generation for training of such meshes (NN, CNN, etc.) using simulation gets have been interesting.
In a first step it is evaluated how simulated results for process signals (pressure and temperature curves registered by in-mold cavity sensors) and part quality (dimensions, weight) match with measured data. Correlations with process parameters are determined and compared between virtual and experimental data. In a second step a decision is made whether such virtual data can be used and how to train AI/ML based methods for process monitoring.

Broaden the possibilities of Moldflow through the use of Python scripts

The Synergy Application Programming Interface (API) makes it possible to automate workflows in Moldflow. The ability to record macros in Moldflow is probably the most obvious example of this and is done in the Visual Basic Script (VBS) scripting language. Here, scripts are created by logging mouse and keyboard strokes within the GUI of Synergy. This process may be the fastest way for simple problems, but quickly reaches its limits for more complex challenges: On the one hand because not all functionalities of Moldflow can be captured this way and on the other hand because VBS seems very “rigid” and “cumbersome” compared to modern scripting languages like Python.
In the course of the presentation, a short Python script is developed line by line in which a process within Moldflow is automated. The audience can thus be convinced of the advantages of Python compared to VBS.
For Python and programming newcomers a way is shown how to start easily with that topic.

AuRhEO – Automated Rheological Efficient Optimization

SABIC and inpro have developed AuRhEO, a tool to optimize the rheological performance of complex (automotive) parts by applying different gate positions and injection sequences automatically, optimizing the part for different CYQ simultaneously.

In this presentation the objectives and the benefits of the tool are illustrated.

Reverse Engineering of Material Data for the Improvement of Pressure Prediction

With increasing standards in process monitoring, gaps between the pressure requirement predicted by simulation and the  actual pressure requirement of a process setting become apparent more often, especially with older material data sets. This can be caused by simplifications made on the model as well as by insufficiently measured data sets.
Accurate calculation of the pressure drop is the basis for accurate warpage calculation.The warpage of the component and the pressure requirement are probably the two most relevant variables for the degree of complexity of the injection mold and therefore also a decisive factor in cost calculation.
As a manufacturer of a wide-ranging product portfolio in a broad variety of geometries and shot weights, we at Gerresheimer are constantly involved in new developments for which reliable simulation results are a decisive basis. In this presentation we will show which requirements are necessary for a simulation model that is comparable with real results and how a material data set can be modified on the basis of such a model and process data from production.

Warpage calculation of carbon fiber skeleton components

In the study presented here, the warpage behavior of skeleton components was simulated using various material parameters. Skeleton components are components in which bars with carbon fibers are inserted for reinforcement. Of central importance is the influence of the coefficient of thermal expansion (CTE) of the inserts on the overall warpage of the skeleton component. Using micromechanical approaches to support Moldflow, a method was developed to better predict the warpage of the component through coupled computation. For validation, the simulation results were finally compared with optical measurements on the original component.

Surface defects in injection moulding caused by processing

High quality surface aesthetics, special for large components, is a very important topic in injection moulding. Surface defects such as pressure lines, flow and sink marks are well known by any component manufacturer. Where they are coming from and how they can be improved, is shown in case of an automotive exterior application made of polypropylene within this lecture.