The development of plastics molding simulation technology started with the plastics filling simulation, and then extended to the gate, runner, and cooling system simulation. In this simulation, the effects of inserts and even the entire moldbase were taken into account. In today’s highly competitive market, the demand for true mold simulations is increasing, as the quality of moldbase design (for example, the layout of the cooling system) can greatly influence the product yield rate.
If the temperature distribution on the mold plate is uneven, mold deformation could occur, leading to flash. As a result, the yield rate will reduce. Another issue is air trap. Luckily, air trap locations can now be predicted using plastics filling simulations. With suitable mold designs including parting surfaces, parting lines, slides, and ejectors placed near the possible air trap locations, decent venting spaces can be included to prevent air traps as well as burn marks.
Advanced users require very detailed analysis results, making the comprehensive mold mesh necessary. However, for experienced users, it took considerable time and effort in the field of mesh building to create matching solid meshes in every component. Consequently, there were only a few successful cases of true mold analysis.
In the simulation analysis process, the Moldex3D Pre-processor enables users to import the geometry model of a whole mold, and build detailed mesh elements for every mold component. Moldex3D R14.0 supports continuous simulation of the non-matching mesh between the part and part insert. It allows users to save both time and effort in matching the mesh. Moldex3D R15.0 even extends non-matching mesh simulation capabilities to the solid mesh generation among the moldbase, part, and part insert.
In the most recent version, Moldex3D R16, non-matching mesh simulation is further comprised of the mold insert and also new mold plate attributes, such as movable and fixed mold plates. The solid mesh of the entire mold system can then be automatically generated with the help of the non-matching mesh technology.
A case of utilizing non-matching mesh in simulating a complete mold system is explained below.
- Simplifying the complete mold model: mold designs are typically comprised of many small components that do not have much of an effect on mold simulation analysis. Therefore, in order to decrease the analysis time and mesh elements, users can now simplify the model by either removing the screws or filling the screw holes in the CAD models first.
- Import the simplified model to Moldex3D Designer BLM and set attributes: set the attributes of the part, runner, cooling channels and mold inserts correspondingly, and apply the new mold plate attributes to set the movable and fixed mold plates. It can hide or show the items with set attributes (Figure 1).
Figure 1. The settings of the complete mold and mold plate attributes.
- Node seeding: set node seeding from the cavity, mold insert to mold plate. The capability of the new node seeding can automatically bring the node seeding data of the cavity or mold insert edges to the adjacent edges of the mold plate and mold insert. This function improves the node seeding efficiency of a complete mold with various components and decreases size gaps of the node seeding density between the adjacent components (Figure 2).
Figure 2. The three-step node seeding data will be brought to the analysis of the next item.
- Build solid mesh: Click the button for creating a solid mesh, and the solid mesh of the complete mold model will be automatically produced.
Figure 3. The solid mesh section of the complete mold model.
- Export MFE file: The software will automatically check the mesh model prior to saving it as a file. If mesh cell intersections are detected, a warning will pop out even though non-matching mesh technology permits a small amount of mesh cell intersections. If the intersection amount is too large, there might be such issue as the non-hollowed tunnels, which has to be altered to prevent analysis issues (Figure 4).
Figure 4. Mesh cell intersection check before mesh export.
- Mold filling analysis: The mold plate material, in this case, is M315 EXTRA and the part material is PC. The default mold temperature and melt temperature are 105 °C and 290 °C, respectively. Users can find good temperature continuity of the non-matching mesh model by observing the mold temperature of the movable and fixed mold plates. It is possible to deliver heat between different mold plates (Figure 5).
Figure 5. The temperature distribution of the mold inserts and mold plates.
The complete mold analysis with the Moldex3D R16 takes into account the true mold design data of the entire mold model analysis. The latest mold plate attribute function allows users to set attributes of movable and fixed plates, and the state-of-the-art non-matching mesh technology enables rapid solid mesh generation of the entire mold system. The detailed mold analysis results provide customers with extra simulation data for mold design, as required. As a result, they are able to improve product yield rate, reduce mold trial times, and efficiently accelerate mold development.
This information has been sourced, reviewed and adapted from materials provided by Moldex3D.
For more information on this source, please visit Moldex3D.