Design for Manufacturing (DFM) in mold production means that mold designers evaluate the manufacturability of the molds in the early stage of mold manufacturing by collecting all the relevant information and applying it in the mold designs. They also have to consider many other factors including flow balance, structural stress, and assembly tolerance in order to ensure a successful mold production. DFM enables mold designers to accomplish mold design changes and optimization in the early stage of the injection molding process and further achieve production goals such as cost reduction, lightweight design and carbon emission reduction.

In traditional mold design process, mold designers would have to decide the total amount of the gates and their locations first, and then draw up a complete runner system in the initial stage of a mold design. Next, they would utilize mold filling simulation software to analyze if the melt delivery system could achieve flow balance. After completing all of the above tasks, they would arrange the cooling channel layout, ejection system and other mold base design. Thus, a flow balance analysis is a critical focus in DFM process.

In order to fulfill the demands for an initial evaluation of the product design in the early stage, Moldex3D has introduced a new feature that offers an efficient solution for attaining quick simulation results with higher computing speed and efficiency. The accuracy of the flow balance analysis has also been greatly improved. Furthermore, in the latest Moldex3D R13, users can run a simulation analysis without importing a complete runner system. They only have to specify the gate locations, and the simulation accuracy can be at the same level as that of a project with a complete runner system.

This solution is based on the same 3D numerical simulation as the analysis project with a complete runner system. It follows the given melt delivery conditions and the law of conservation of energy among the gates when the flow is balanced. In the filling analysis, it also has dynamic adjustments in order to achieve the same analysis accuracy as the one with a complete runner system. Therefore, users can reduce the analysis time spent on a runner system and quickly determine the gate amount and gate locations. The iterative design time after the runner system is added can be further reduced.

Take a cell phone shell product (Fig.1) as an example to compare the results of the traditional analysis process and Moldex3D enhanced solution.

Fig. 1  The gate locations and the thickness distribution of the product

In the traditional analysis process (Fig. 2-left), mold designers would have to create a complete runner system based on the gate locations. In the analysis process of Moldex3D enhanced solution (Fig. 2-right), users can directly proceed with the simulation analysis without creating a runner system. As shown in the figures below, the simulation accuracy of both gate contribution analysis results is almost the same.

                                               Integrated Runner Layout                                                  Quick Design without Runner Layout
Fig. 2  The comparison of the simulation results of the traditional analysis process (left)
and Moldex3D enhanced solution (right)

In addition, Moldex3D enhanced solution can also improve the gate design efficiency. Take a car interior product as another example (Fig. 3). With Moldex3D enhanced solution, users can study the history of the flow rate changes in each gate area and identify the gates with poor flow efficiency to further adjust the gate locations and optimize the flow balance.

Fig. 3  Moldex3D enhanced solution displays the history of the flow rate changes in each gate area

Simulation analyses enable users to understand the melt flow behavior inside the molds and predict potential molding issues to prevent product defects and deformation. It also facilitates a quick validation on design changes and helps users optimize part design and processing parameters with ease. Moldex3D enhanced solution can further spare users’ time that would normally be spent on building a runner system in the traditional simulation process while still being able to achieve high analysis accuracy. Especially when users have to change gate locations, Moldex3D enhanced solution is an ideal aid that can efficiently and rapidly help optimize mold design and significantly reduce the simulation time. Moreover, Moldex3D’s enhanced calculation capability can provide a quicker, more efficient and reliable simulation analysis which allows users to speed up the product and development process to maximize their competitiveness in this rapidly-changing global market.