Our automated, interactive ProtoQuotes with real-time pricing information and free design for manufacturability (DFM) analysis are one of the most valuable tools you can get at Proto Labs. You can upload a 3D CAD model online at any time to receive a quote within hours.
The DFM analysis helps eliminate potential problems like sink, challenging undercuts or walls that are too thin or thick. Once a part design is ready and a quote approved, production begins almost immediately.
See how easy it is to navigate ProtoQuote with our quick video.
Last week we discussed wall thickness by resin types, where we learned the importance of uniform wall thickness and provided a guideline on thickness based on your material selection. Another very useful resource in selecting materials is a mold flow simulator, which tests different resins and how they fill using accurate molding pressure.
Melt Flow Index
All materials have a different melt flow index (MFI), but what does this exactly mean? MFI is a measurement taken on how well a material flows at a high temperature through a specified diameter during a 10 minute test. This measurement for MFI is calculated into grams per 10 mins. Typically, higher numbers mean you have a much better flowing material that can fill thin wall geometry easier. But that doesn’t tell the entire story as a higher MFI doesn’t always mean that you won’t encounter any issues on thin part geometries. All materials have varying melting temperatures, so compare MFI between different families of materials such as polyethylenes and polypropylenes, which have about a 40° difference in testing temperatures.
Knowing the Material
Work with Proto Labs’ customer service engineers (CSEs) as soon as you begin quoting your parts and tell them what material you are considering having the parts produced in. Having this information early allows them to properly analyze part geometry for appropriate wall thickness using the MFI of the selected material. Often times, a part that is too large or has features that are too thin for a selected material will require an increase in wall thickness or an alternative material to be chosen.
How does a mold manufacturer know the selected material will work? This is where the software takes over. Proto Labs uses a proprietary ProtoFlow® fill analysis program that is truly unique to our molding technique. We have several available materials that can be tested using a resin’s MFI and your CAD geometry.
The ProtoFlow simulation shows the resin fill of a part through a single gate location at the end of the part and the color represents the part filling through to completion.
After your CAD model has been uploaded, gate location and quantity of gates are selected based on your part’s geometry and material. A simulation is then run by our mold designers to review:
- gate location
- knit lines
- incomplete fill
- balanced fill
- and most importantly, fill pressure
Design for manufacturing (DFM) analysis provides information to not only improve the design of your injection-molded part at Proto Labs, but suggests improvements that can be applied regardless of your manufacturer.
Once you upload your 3D CAD model, you’ll receive an email inside of 24 hours — typically, within only a few hours — that contains a link to your quote. Quotes are generally defined as an estimated cost for a particular service, but arguably, the most valuable information that you receive in your Proto Labs quote is our automated DFM feedback.
The manufacturability feedback addresses considerations like:
- Wall thickness
- Undercut regions
- Thin and thick sections
- Material flow
- Design complexity
- Areas that cannot be manufactured
- Gating and ejection
Proto Labs specifically uses this information to explain wall thickness and draft based on our manufacturing capabilities to machine an aluminum mold through three-axis CNC milling. These are unique to our manufacturing process, but are great guidelines to improving your part design in general.
Customers often times will begin designing a part with no draft or wall thickness concern and bring this design to our quoting software for a quick review at the end of the day. In many cases, by the time you arrive back at work, you may have your DFM analysis waiting. You can then apply those changes, or speak with one of our experienced customer service engineers who can help explain how to simplify your design or discuss why we have capability issues with how your part is intended.