Aug 9, 2017
We know that our community always has burning questions about the world of 3D printing. That’s why we hosted our first Ask Me Anything (AMA) session, with our 3D printing materials expert, Tom Heijmans! It was a great chance for us to share the knowledge that we’ve acquired over the years, and for you to find out everything you ever wanted to know about our materials.
If you're new to the concept, AMA is a type of live forum made popular by online communities such as Reddit and LiveJournal. In an AMA session, people can ask anything about a particular topic to a particular person for a limited time.
In our first Ultimaker AMA, the spotlight was on our Materials Engineer Tom Heijmans, whose task was to answer all the questions that the eager Ultimaker community had lined up.
"It’s great to work in a multidisciplinary company like Ultimaker. I can learn about software and hardware, but I get to work with product management, marketing and support as well. I don’t think I can call Ultimaker ‘small’, but I still have a lot more responsibilities than I would have in a bigger company." - Tom Heijmans
Over the course of 1.5 hours, Tom answered questions posted on our forum and on Twitter (using the hashtag #UltimakerAMA). Thanks to everyone who asked a question, Tom had a lot of fun answering them. You can read the whole AMA session here. In the meantime, here’s a summary of the best topics that came up in conversation.
Welding, smells and humidity
Our newly released material PP was a popular topic among participants. DiderKlein asked Tom if it's possible to weld PP parts together, as you can for metal. Tom answered that because PP is very inert, it is difficult stick parts together using adhesives. He added that it is possible to weld PP using a soldering iron, although as it can create fumes, using an air extractor is highly recommended.
Another PP question came from Nicolinux, who asked if PP can survive outdoor applications. According to Tom, no polymer is completely stable under strong UV light---and PP is less stable than most because its 'simple' polymer chains are easily broken up by UV radiation. However, PP is very good at resisting moisture and other weathering conditions, so as long as it is not exposed to direct sunlight, it can be good for these purposes.
Anyone familiar with 3D printing knows that using different materials can create a variety of pleasant and not-so-pleasant smells. Ahoeben asked Tom what his favorite smelling material is. Tom replied that so far, his favorite smelling material is PLA, because it has a sweet smell that is not very pungent. He added that when combined with a dual print material such as PVA, it can even make him hungry!
On the topic of PVA, Swissengineer asked what happens when PVA is exposed to humidity and how it affects printing.
Tom replied that when PVA is exposed to humidity, water molecules slowly creep into the polymer structure. Because water molecules are really attracted to polymer chains, this happens faster with PVA than with other materials. Water molecules actually push the polymer chains apart, decreasing the effective glass temperature of the material. When too much water is absorbed, the material becomes moldable at room temperature, causing filament to melt together. Wet PVA prints with a lot of bubbles and will look more cloudy. When PVA has absorbed too much moisture from the ambient environment, it will print less reliably as it can get stuck in the feeder.
How does a materials department work?
Aside from materials, Tom also received questions about Ultimaker's materials department and how it functions. Dim3nsioneer was curious about the materials team’s workflow when developing a new Cura profile, and the tests and results that are required before it is ready to distribute to users.
Tom explained that first, the team will start by finding the processing temperature by printing and measuring the extruded part using calipers and scales. After this, they will try and find fan settings at which the strongest layer bonds are achieved, as well as a suitable bed temperature that won’t warp the material. Before a profile is distributed to users, it will be thoroughly tested at Ultimaker by the testing team, as well as by beta testers outside of Ultimaker. Their feedback will decide whether a profile or material can be successfully launched.
These were just a few highlights of our AMA session. If you want to know what else was asked, like if we use ISO standards while testing layer bonding, the percentage of beards in the materials team, and the next new 3D printing material Tom would like to see, you can see the full discussion here.
You can also find Tom's Ultimaker profile here.
Got a burning question?
We'll be running more AMA sessions in the coming months, so stay tuned and get involved! Would you like to talk to one of our hardware engineers or software experts? We invite you to influence who will be our next AMA candidate, so let us know who you’d like to talk to.
If you’ve got any other questions in the meantime, just get in touch, or join the conversation in our lively community.