Julliette Combe is a mechanical engineer. She began working on 3D printing during her master thesis on nano 3D printing. When she joined Formlabs, she first went into the business development team for product partnership and worked on custom products for key accounts.

She moved into application engineering and has been there for the past two years. She conducts research on applications–use cases in particular–for the manufacturing industry. She typically does research on how to use 3D printing for common manufacturing processes in injection modeling. Then she creates technical content for her research.

JC: The 3D printing technology is largely accepted by engineers. Something around three out of four engineers are using 3D printing at the moment, and probably half of them are using it in-house.

What is interesting to see is why it’s being used, and this is exactly what I’m researching. The first application that we look at is obviously prototyping. This is the first application that comes to mind for 3D printing. And what is interesting is to try to expand that beyond prototyping. And in particular, I’m looking into how to use 3D printing for rapid tooling. This is a very exciting topic actually. Maybe it doesn’t sound so attractive because it’s rapid tooling. It’s a very, let’s say, old industry, but it’s very interesting what can be done with 3D printing.

MPF: My sense is that rapid tooling is actually probably more used. It’s just not covered as much by the media because it’s just not as sexy as some other topics.

JC: Yeah, exactly. We are really looking into what can be done for mass customization and for limited series of end parts; what actually can be done on the factory floor is really interesting. But not only on the factory floor, but also just how a product designer can use 3D printing from the beginning of the product design cycle with very early prototyping, all the way to production with using 3D printing for tools at some point in the design.

MPF: What are some of the trends you’re seeing in tool development using 3D printing? What are some of the key benefits of using 3D printing in this way?

JC: Yeah, there are two types of tools, let’s say. First, there are what we call manufacturing aids. This will be some sort of jigs, fixtures, and measuring devices. All types of work work-holding devices that can be used on the factory floor. At a different stage of the production and assembly process, there’s quality control. And those are very simple parts, but they are important to increase efficiency. So because they need to be customized for assembly to every different part that is being produced, the fact that you can actually print it in a few hours and customize your device is huge for time and cost-saving. That will be the first aspect.

And there is a second aspect that will be what I call rapid tooling, that in general will be for producing molds, dies, forms, and all sort of what we commonly call tools for manufacturing process like injection molding, but also thermoforming, composite manufacturing as well, such as, for example, some form for hand lamination as well as using in the pre-break process. Vacuum bagging in an autoclave is also something that we are studying right now, and even sheet metal forming as well. Printing dies forming sheet metal. That’s also quite exciting.

MPF: Let’s go into materials a little bit. Are there enough materials for the designer to work with when it comes to developing tooling either for the machine tool or for injection molding?

JC: This is definitely at the core of the question because this is the different type of material that will expand the possibility in use cases. What is interesting actually, with resin-based 3D printing, is that you have a lot of different materials with a lot of different mechanical properties but also thermal properties. At Formlabs, we have, for example, two materials that have a high thermal resistance, and specifically, one is called rigid 10 K material. And this is a very rigid material, very stiff, and also very resistant to high temperatures. So this is great for injection molding. We’ve seen this application developing a lot since we released this material, and this is opening a lot of capabilities, but we also have material that’s not necessarily with high terminal resistance, but more, some flexibility, some may be good elongation. So that’s for example, that can be used in achieving the fixture.

MPF: You mentioned, did I hear you say, sheet steel? How is this sheet steel used in 3D printing? Are people printing with that to create molds?

JC: So, we’ve been exploring the concept of using 3D printed dies to press sheet metal. Obviously, that will be quite thin sheet metal. It is really interesting to see that with dies that are 3D printed with poly material. This is a plastic material that you can actually properly band metal sheets and actually at very good resolution, really good accuracy. So that’s also interesting just for prototyping your parts in sheet metal to be able to produce the tooling that you will require for your process. You can produce it in 3D printing material.

MPF: Since you’re doing a lot in research, can you go into a little bit about what you’re looking into? What are some of the trends that engineers can expect to see out of 3D printing in the next few years?

JC: I see a trend that we are exploring more, where we are developing more material with new mechanical and thermal properties. We can actually tackle and produce tools that are able to handle high, intensive processes. And I will be able to produce high-performance parts. This is an industry that has high requirements. Producing composites is intensive and the composite material itself is high-end material. So it doesn’t come to mind that easily that you can actually produce it with 3D printed polymeric tools, but as we develop more and more functional material, we will be able to produce that more easily.

MPF: Now, where would you like to see 3D printing going in the next few years?

JC: I would like to see every designer using 3D printing, not only for prototyping but also for tooling. Typically, I start to see that with product designers that will be using 3D printing, direct 3D printing for prototyping first, and then after that, they will print their tool so that they can prototype series. So low volume series of typically injection molding for like hundreds of units, they could also do it with thermoforming, for example. And then this is what we call bridging the gap between prototyping and production. Actually, a lot of people refer to that saying how rapid tooling is really the great tool to fill this gap that we see between prototyping capabilities and all those manufacturing methods that are really suitable only for high volume production. So yeah, this is really what I would like to see in the future, how all product designers will be able to bridge this gap.

MPF: So what needs to happen in order for the designer to help bridge that gap?

JC: Well basically we need to really try, so make the test experiments to see that the 3D printed tool works. To some extent, obviously, we cannot use a 3D printing model to produce hundreds of thousands of units. This is not possible. And it’s also not the goal obviously. But it’s just not being afraid to use 3D printed polymeric tool in a very intensive process and try it and see the benefit of just having hundreds of parts being made with this process.

MPF: Do you think that maybe there’s an issue with the development time required to make tooling with 3D printing? That may be one of the inhibitions in experimenting with 3D printing or is it more just familiarity? People just need to just play with it, get familiar with it, and get comfortable with it?

JC: I think actually first is a problem of conception. Just as I say, having the idea of having a plastic tool, a polymeric tool to work with an intensive process is not really something we have in mind, but also just disrupting processes that are in place is not always that easy. Especially if we look at companies that have established processes on how they will move to production. Just taking the risk of trying something like new technology and seeing how it works. Yeah.

MPF: Do you have any design tips that would make the entire process easier with developing tooling using 3D printing?

JC: Yeah. If I think about it more in terms of the injection molding idea because this is the one I’ve studied the most lately, but I think this applies also to every mold-making process. When designing a metal mold, if you have experience in designing a metal mold, they won’t be much trouble designing a 3D printing mold. Actually, I’ve been working with a customer at a technical college in the US, and we’ve done design classes with him that you can find online. And he’s teaching how to design metal injection molding molds. It’s really his class. And to teach his students, he’s actually teaching them to 3D print it first. So they first design the mold for 3D printing it, and they 3D print it, and they inject from the 3D printing mold, but this is a class for designing a metal mold.

In his opinion, there is really not much to adjust. However, you really have to keep in mind. So that would be my advice. That a polymer 3D printed tool is more fragile than a metal tool. Obviously, it’s more fragile. It’s also less accurate. So when you’re thinking about designing a mold that will be handling high pressure and high temperature, you should think about designing it to make the least effort as possible on that mold. There are some tips like that. For example, having a large gate, having large vents, this will really decrease the pressure inside the cavity of the mold. If you always keep in mind, I want to protect my mold against this high pressure and try to make it live as long as possible, you will think about exactly having large gate, large vents, having that very and not too deep of design for your cavity. Things like that are really important.

MPF: So it sounds like the kind of design requirements or something that you would use for metal are very similar to what you would use in 3D printing. Is that correct?

JC: Yes. You can also accommodate similar with a structure of the mold. So if again, I think about injection molds, then you can have side action mold the same way. And actually, if you think about… If you don’t have any knowledge in designing molds, we have actually a lot of users that don’t have any knowledge and want to start doing this application, 3D printable would be easier to design because you might not need any cooling channels, for example. You might not need any ejector pins. That would also simplify the design, but you can add them if you want. It’s just something you can add, but usually, it’s not necessary.

MPF: The great thing about 3D printing is it’s easy to experiment.

JC: Exactly. Yeah. And that’s also the second thing to keep in mind is it costs nothing to add more holes or more design complexity. Actually, it’s just something you’re going to add in the design card, but it’s not something that’s going to be more complex to manufacture, which is not the same for machining with a CNC machine.

MPF: So, basically good basic injection molding design tips that you would normally do, you can absolutely apply to 3D printing. Plus you can add additional complexity depending on what you need to do.

JC: Exactly. And also, for example, for a thermoforming mold, I’ve had customers that told me that their thermoforming mold needs a lot of holes to have to air circulating and they actually can add as many holes as they want to the 3D printing mold. So that’s also really a great way to use the freedom of design from 3D printing and the fact of having more holes and more air vents actually increases the quality of the air pressure on your mold. Then you will have a better surface.

MPF: Any final words that you would like to say?

JC: Yeah, this is really one thing I really want to, how do you say, keep open is that they are so much that can be done with tooling, with 3D printed tools. And that’s, as I said again, is something that needs to be tried. So I really recommend to product designers and engineers don’t hesitate to try a tool with 3D printing. It really might work, might be of great use, and a great help.

And you can just keep your design and then improve it. This is really the advantage for product design and developing a design with the help of 3D printing is that you can iterate as much as you can in a very quick way. So I was just actually chatting with a customer recently that told me using 3D printing, fully printed injection mold, they managed to produce the project in five weeks instead of a year. So that was really… That was really a shortcut.

MPF: That’s quite a time-saving.

JC: Definitely.

MPF: Well, I appreciate you being here with me today, Julliette. Thank you so much for your time.

JC: Thank you very much. It was a pleasure.