One of the keys to a quality plastic injection molded part is an accurate mold – one that produces consistent pieces time and time again. So how is that accomplished?
So, now you have a better idea of what goes into making a plastic injected molded part. But there's one secret weapon that Slideshare didn't talk about. It's a step that comes before you start making the tool, in fact this ingredient takes place during the design stage. Taking your mold from good to great is as simple as testing it via Mold Flow Analysis (MFA). This software simulates your mold conditions before opening your wallet to pay for tooling. The effect MFA has on the quality of the mold, the performance and appearance of your product makes it an indispensable component of any plastic injection molding design project. Note: MFA software is expensive, but the return on investment is substantial.
What is Mold Flow Analysis?
Mold flow analysis (MFA) software simulates the flow of plastic, which allows you to elevate part and mold design to create products of impeccable quality. Like other simulation software, MFA gives you a virtual sneak peek into how your material of choice will fill the mold's cavities and offers a head's up on potential problem spots. The benefit is obvious, right? Simulating the process digitally means you can make changes BEFORE A TOOL IS CUT. This one thing is a big cost savings, not to mention a time saver as well.
When Should Mold Flow Analysis be Used?
In case it wasn't clear, MFA is conducted before tooling production launches. (It wouldn't make much sense to use it afterward!) Using a selected gate location and material properties, the software is able to predict how the part will fill during molding. Different data points can be assessed, including pressure, fill time and melt temperature. Doing so allows for optimization of the process before tool manufacturing ever begins.
Is Analysis Necessary for Every Application?
The short answer: not necessarily. The following factors can help you decide whether MFA should be used for your application:
The more complex the product geometry, the more benefit you'll receive from MFA. Why? When the product's design is more intricate, the flow is less predictable. It's easier to predict how a simple mold design would fill, for example.
Tight tolerances are an anathema to plastic injection mold designers anyway. Software that can analyse and demonstrate whether a product will meet spec prior to cutting a tool is a godsend.
Clearly a project would have to meet certain financial requirements to warrant the investment of resources — time, software and talent — to run the tests.
Engineers know the fill patterns of standard materials but others — especially materials that include fillers — benefit from up-front analysis.
Here's a video from MFA software maker Solidworks demonstrating how the software works and why it can be an invaluable tool during the design process. There are other MFA software makers; you should look for the software that best suits your project's needs.
There are multiple benefits to MFA. They include:
- Resolution of wall thickness complications
- Gate location optimization
- Mold cavities fill consistently and uniformly
- Discover defects in design geometry
- Prevent expensive tooling errors and rework
- Enhance manufacturability
- Reduce time to market
- Boost efficiency and quality
- Reveals potential visual defects, including air traps, sink marks and weld lines
- Assess different material options, pre-production
- Provides data to support design changes
You'll find a variety of MFA software on the market. They all perform similar functions but are geared toward different users along the spectrum. We found this comprehensive article What Injection Molding Software Can Do For You on the Digital Engineering News website. Rather than rewrite the material, we recommend you read it to learn more about the different types of MFA software and how each is applied.
We also recommend that you work with a seasoned contract manufacturer, one that can guide you through the Design for Manufacturing (DFM) process from start to finish. Find a manufacturing partner who has the know-how and experience to handle the flow analysis for you.
- DFM Rules of Thumb for Making Accurate Plastic Injected Parts
- Material Selection in Manufacturing: Metal or Plastic
Check out our free webinar that features tips on manufacturing plastic injection molded parts more efficiently!