What is Flow simulation?

Flow simulation is an essential tool in the design and development of injection molds for plastics, enabling the prediction of how molten material will behave inside the cavity before the mold is physically built. This type of computational analysis is based on fluid dynamics and thermal modeling algorithms and is crucial for avoiding errors, reducing development time, and improving final product quality. In industry, it is referred to as flow simulation in injection molds, and it is standard practice in advanced engineering projects.

Through predictive mold filling analysis, engineers can visualize how the polymer flows through runners, gates, and cavities. This makes it possible to detect potential issues in advance, such as weld lines, air traps, short shots, pressure imbalances, overheating zones, or premature solidification. With this information, designers can adjust part geometry, gate positions, cooling channels, or injection parameters—without needing a physical prototype.

One of the key benefits of flow simulation in injection molds is the reduction of costs associated with late-stage modifications. By anticipating and correcting potential problems during the design phase, manufacturers avoid producing faulty molds or carrying out costly rework. Additionally, it helps optimize cycle times, improve thermal distribution, and ensure uniform filling in multi-cavity molds, leading to more efficient and stable processes.

Advanced simulation tools such as Moldflow, Sigmasoft, or Moldex3D offer features that go beyond basic filling analysis. They can simulate packing, volumetric shrinkage, and warpage of the final part. These platforms also model heat transfer, material behavior based on rheology, and the effects of the cooling system—providing a comprehensive overview of the process.

Plastic part design optimization through simulation is particularly valuable for parts with complex geometries or made from specialty materials like mineral-filled, glass fiber-reinforced, or high-viscosity engineering plastics. In these cases, poor flow distribution can directly impact the part’s functionality, dimensional stability, or surface finish.

At companies like Plásticos Lezo, specialists in technical injection molding, flow simulation is incorporated from the early stages of each project. It helps assess not only how the plastic fills the mold, but also how it affects the entire process—from mold design to injection and cooling parameter selection. This proactive approach ensures product quality and production efficiency for the client.

Moreover, flow simulation in injection molds serves as a powerful tool for training and communication. It provides intuitive visualizations of what happens inside the mold, helping multidisciplinary teams make better technical decisions and reducing miscommunication between design, manufacturing, and production departments.

In summary, flow simulation is a strategic element in predictive mold filling analysis and plastic part design optimization. Its use improves product quality, shortens development timelines, and reduces overall project costs—making it an indispensable practice in mold engineering and plastic processing.