At Beaumont, we deal with all aspects of Autodesk® Moldflow® simulation software. We are the only company in the world that offers material characterization, software training, simulation analysis, and software sales all under one roof.
This article focuses on just one aspect of Moldflow: simulation. We have asked the Beaumont Engineering Team to dive into the steps they take to ensure every simulation is successful.
Beaumont’s Steps to a Successful Moldflow Simulation
The Beaumont Team takes a holistic approach to injection molding optimization using Autodesk Moldflow simulation software. Our team of plastics engineers (yes – all of our simulation analysts have degrees in plastics engineering) communicates with our customers every step of the way, and can help optimize new parts before the mold build or troubleshoot existing parts that are causing headaches on the mold floor.
Every simulation project begins the same way, with an initial evaluation of the part geometry.
Initial Part Geometry
Preliminary simulation analyses are performed to investigate underlying part geometry issues, such as: locally thin vs. thick regions, non-optimal rib and boss thicknesses, poor radii dimensions, and other similar concerns. For the analyses, careful consideration is given to which mesh type is most applicable to the geometry.
Part design recommendations are discussed with the customer, and any revisions are re-simulated and evaluated. Once the part geometry is optimized, the simulation process moves on to gate location optimization stage.
Gate Locations
The selection of the gate location(s) within an injection mold is critical to the final part quality. The Beaumont team reviews every aspect of part filling and packing analyses when determining the optimal gate location(s).
The orientation of the polymer can significantly influence part shrinkage, warpage, and strength, and filled polymers further exacerbate these orientation effects during the molding process.
Balancing end-of-fill conditions within the mold cavity is generally preferred because it minimizes filling pressure requirements and provides the most balanced intra-cavity molding conditions. The positioning of weld lines is also critical to part quality, as these can often serve as failure points during final part application.
Wall thicknesses also influence the gate location(s). Gating into thicker regions allows for the most desired filling and packing conditions, minimizing sink, void, and warpage potential.
Once the optimal location(s) have been determined, the feed system can be optimized.
Feed System
Optimization of the feed system is a balancing act between injection pressure requirements, packing ability, rheological balance, runner design / type, and runner volume. Our engineers use the customer-supplied injection pressure requirements to determine the minimum runner volume required to produce high quality parts while minimizing scrap costs.
Once the runner system has been optimized, our engineers may or may not recommend implementing Meltflipper™ technology. In the majority of applications, this can greatly reduce or eliminate potential issues at the injection molding machine.
After the feed system is optimized, our team moves on to their evaluation of the mold cooling system.
Cooling Optimization
Cooling optimization begins by analyzing the preliminary cooling design to identify problem areas like hot spots, excessive circuit temperatures, circuit pressures, turbulence, etc. Our team then makes modifications and adjustments to the circuits to eliminate these potential issues.
Typical modifications include adjusting the spacing between the cooling lines and spacing from the lines to the part surfaces, adding additional cooling lines, utilizing the mold’s steel components with higher thermal conductivity to gain additional heat extraction, and implementing larger diameter channels.
Once the Beaumont Team and the customer are satisfied with the cooling results, the final stages of the simulation process begin: part warpage reduction and final process optimization.
Warpage Optimization
The objective of a warpage optimization study is to determine the root cause of warp, then adjust accordingly.
There are three main types of warpage that our team works to identify and eliminate:
• Variation in shrinkage from region to region (differential shrinkage)
• Temperature differences from one side of the mold to the other (differential cooling)
• Variations in the magnitude of shrinkage in directions parallel and perpendicular to the material orientation direction (orientation effects)
After the causes of warpage are identified and a solution is established, our team can recommend adjustments to further improve part quality and warpage-related issues.
Final Process Optimization
The final phase of a complete analysis package involves a series of process optimization studies. These studies include, but are not limited to: fill time optimization, pressure and clamp tonnage reduction, part strength optimization (i.e. weld line strength), and warpage reduction.
Our engineering team uses every tool at their disposal to ensure an optimized final process that can be plugged directly into our customer’s injection molding machine during initial processing.
DOE (Design of Experiments) studies are typically performed to determine which process variables are having the most significant impact on part quality, while providing the widest processing window.
Communication
Our engineering team includes one key component in every step of their simulation analyses: communication. Our customers receive as much or as little guidance and feedback as they want, and our team includes comprehensive reports and live web meetings with each step of the process.
Our customers are never kept in the dark, and our team answers as many questions as necessary to make sure they understand the reasoning behind every recommendation.
Our engineering team prioritizes one thing above all else during their simulation analyses: customer satisfaction. Our team goes above and beyond to help our customers produce in-spec parts as efficiently as possible, beginning with first samples.
If you haven’t tried Beaumont for your Moldflow® simulation analyses, what are you waiting for?
