July 26 4.30pm CEST. 'I'm a Material Engineer at Ultimaker for 3 years. AMA'.

[SandervG 1,521]

'Hi, I'm Tom (@TomHe). I'm a Material Engineer at Ultimaker, I started in 2015 as an intern to finish my Chemical Engineering Master from Eindhoven University of Technology.' ...

Tom has worked for Ultimaker for 3 years already and has played a role in many of the Ultimaker products we all use regularly. Tom started in 2015 working on PVA. His graduation project evolved around producing and 3D printing carbon nanotubes, and graphene filled materials (for electrical conductivity). Other responsibilities Tom joyfully carried; the first print profiles for the Ultimaker 3 and everything PVA related. Putting together 3D print profiles also include determining the best nozzle geometry, Cura features and supplying values for all settings used in Cura.'

Tom will start replying at 4.30pm CEST.

Edited July 26, 2017 by Guest

[SandervG 1,521]

The topic is open, if you already have some questions feel free to post them here! I have collected some over the last few days (a couple came in via Twitter) and I will also share them here at 4:30pm.

First question from @Didierklein, 'I have a question, i recently discussed with someone who is using PP at his work, he told me it's possible to weld PP parts together (like you do for metal). He was very interested in the new PP filament from UM, and asked me if it would be possible to do it with printed parts.

Also is it possible in the future to have different colors for PP ?'

[SandervG 1,521]

@kmanstudios, are you almost ready?

[ahoeben 1,948]

Hi Tom, which are your favorite and least favorite smelling printing materials?

[SandervG 1,521]

We can now also tag Tom via @TomHe

Edited July 26, 2017 by Guest

[le_avion 1]

Having hard time with printing PVA for support. What material does PVA bond with best?

[Swissengineer 25]

Hey Tom,

What happens when PVA is exposed to humidity? How does it affect the printing?

If a PVA spool got too much humidity, can I heat it up in the oven to remove the humidity?

[Tomhe 21]

The topic is open, if you already have some questions feel free to post them here! I have collected some over the last few days (a couple came in via Twitter) and I will also share them here at 4:30pm.

First question from @Didierklein, 'I have a question, i recently discussed with someone who is using PP at his work, he told me it's possible to weld PP parts together (like you do for metal). He was very interested in the new PP filament from UM, and asked me if it would be possible to do it with printed parts.

Also is it possible in the future to have different colors for PP ?'

Hey ho let's go

About welding PP:

PP is known to be very inert, so glueing the material is very hard. But it is possible to weld it! When I print flasks/vases/etc with PP and there is a tiny leak, I use a soldering iron at 200C to weld it close. Maybe a lower temperature would be better, but I can’t set it any lower. And please do this with air suction nearby, because a bit of plastic residue can stay on the iron and create some nasty smells. Clean the hot iron afterwards.

[Tomhe 21]

The topic is open, if you already have some questions feel free to post them here! I have collected some over the last few days (a couple came in via Twitter) and I will also share them here at 4:30pm.

First question from @Didierklein, 'I have a question, i recently discussed with someone who is using PP at his work, he told me it's possible to weld PP parts together (like you do for metal). He was very interested in the new PP filament from UM, and asked me if it would be possible to do it with printed parts.

Also is it possible in the future to have different colors for PP ?'

PP colors:

If there is a big market call for colors of PP, we can give it a try. I personally like it more when engineering materials are pure polymer, without pigments. For ABS and PLA I understand that people want a range of colors, do you think it’s important for other materials as well?

[Tomhe 21]

Hi Tom, which are your favorite and least favorite smelling printing materials?

My favorite is PLA, I like the sweet smell and it’s not very pungent. It does make me hungry sometimes, especially when combining it in a dual print with the sour-smelling PVA. My least favorite is PC. PC really has an unpleasant smell, especially if you print it too hot.

[Tomhe 21]

Having hard time with printing PVA for support. What material does PVA bond with best?

It seems to bond best to Nylon and TPU’s, but with Cura 2.6 bonding to PLA is much more reliable for me as well. CPE is possible as well now we have the Cura 2.6 new features. For me it works best if I first clean the nozzles (outside part), and do a good bed levelling and XY calibration before I do a long/challenging print.

[Tomhe 21]

Hey Tom,

What happens when PVA is exposed to humidity? How does it affect the printing?

If a PVA spool got too much humidity, can I heat it up in the oven to remove the humidity?

When PVA is exposed to humidity, water molecules slowly creep into the polymer structure. Because the water molecules are really attracted to the polymer chains, this happens faster with PVA than with our other materials. The 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 and the filament will melt together. Wet PVA prints with a lot of bubbles, and will look more cloudy. It prints less reliably as it can get stuck in the feeder.

If you dry the filament in time (before it’s too wet) you can easily print with it again. Drying should be done at ~50-55C for about 1.5 - 2 hours. I always put my spool in a cardboard box on top of a hot build plate. The box is just there to trap the heat. You shouldn’t use a household oven as those aren’t meant for these ‘low’ temperatures (and aren’t meant for heating plastics). If you heat it too hot, it can deform. And wait for the filament to cool down to room temperature before printing, otherwise the feeder could deform the PVA.

[Nicolinux 288]

Hi Tom, here is my question I asked via Twitter:

Can I use PP for outdoor prints? Do you have some data on longterm effects (weather, UV)?

[SandervG 1,521]

We also got some questions via Twitter and other channels, I'll also share some of them here:

First one;

- @Tomhe; How do you like working at Ultimaker, and how big is the materials team?

Perhaps interesting to add; since when do we have a materials team, and actively have people working on 3D print materials?

Edited July 26, 2017 by Guest

[Dim3nsioneer 557]

Hi Tom, here is my question I asked via Twitter:

Can I use PP for outdoor prints? Do you have some data on longterm effects (weather, UV)?

And as also mentioned already on Twitter, can you maybe comment on the outdoor capabilities of some other UM materials too?

Edited July 26, 2017 by Guest

[SandervG 1,521]

Having hard time with printing PVA for support. What material does PVA bond with best?

It seems to bond best to Nylon and TPU’s, but with Cura 2.6 bonding to PLA is much more reliable for me as well. CPE is possible as well now we have the Cura 2.6 new features. For me it works best if I first clean the nozzles (outside part), and do a good bed levelling and XY calibration before I do a long/challenging print.

@Tomhe, Why is it important to clean the outside part of your nozzle, for material bonding?

[Tomhe 21]

Hi Tom, here is my question I asked via Twitter:

Can I use PP for outdoor prints? Do you have some data on longterm effects (weather, UV)?

No polymer is completely stable under strong UV light. PP is less stable than most, because of the ‘simple’ polymer chain that is easily broken up by UV radiation. So I wouldn’t use PP for an application where it must be durable and is exposed directly to sunlight. PP doesn’t react on other weathering conditions like moisture, so for those applications it would be a good material.

We don't have any data on longterm weather effects yet, it's a really new material!

[Tomhe 21]

Having hard time with printing PVA for support. What material does PVA bond with best?

It seems to bond best to Nylon and TPU’s, but with Cura 2.6 bonding to PLA is much more reliable for me as well. CPE is possible as well now we have the Cura 2.6 new features. For me it works best if I first clean the nozzles (outside part), and do a good bed levelling and XY calibration before I do a long/challenging print.

@Tomhe, Why is it important to clean the outside part of your nozzle, for material bonding?

Cleaning the outside of the nozzle is important for the automatic bed leveling. Better leveling leads to better adhesion.

[Tomhe 21]

We also got some questions via Twitter and other channels, I'll also share some of them here:

First one;

- @Tomhe; How do you like working at Ultimaker, and how big is the materials team?

Perhaps interesting to add; since when do we have a materials team, and actively have people working on 3D print materials?

It’s great to work in a multidisciplinary company like Ultimaker. I learn about software (I can write pretty much all the quality/variant/printer/etc files for Cura myself) and hardware, but I have to work with product management, marketing and support as well. I don’t think I can still call Ultimaker ‘small’, but I still have a lot more responsibilities than I would have a in a bigger company.

The materials team now consists of seven members: four chemists/physicists and three 3D printing experts. Only one in the team works here less than two years.

I believe the first material researcher at Ultimaker was @Nallath's dad, but I don't know exactly when he started working here.

Edited July 26, 2017 by SandervG

[Dim3nsioneer 557]

Cleaning the outside of the nozzle is important for the automatic bed leveling. Better leveling leads to better adhesion.

In addition to cleaning the outside, wouldn't it be better to avoid the nozzle dip into the PVA prime blob at the the beginning of the print?

Edited July 26, 2017 by Guest

[Tomhe 21]

Hi Tom, here is my question I asked via Twitter:

Can I use PP for outdoor prints? Do you have some data on longterm effects (weather, UV)?

And as also mentioned already on Twitter, can you maybe comment on the outdoor capabilities of some other UM materials too?

I think CPE, CPE+ and PC will be the most stable in outdoor conditions, but I don't have exact numbers available to prove it. The polymer chains aren't as 'simple' in these polymers as those of PLA, PP and Nylon, the aromatic groups could dissipate the UV energy easier (that's what I think/heard).

[SandervG 1,521]

@Tomhe, another question for you: How difficult was it to get PVA to work reliably, and what was the most difficult part of it? Speaking of difficult parts, what do you consider the most difficult part about your job?

[SandervG 1,521]

And I had a question from myself too

How far away are we from printing with conductive materials, what needs to happen for this to become widely available?

[Tomhe 21]

Cleaning the outside of the nozzle is important for the automatic bed leveling. Better leveling leads to better adhesion.

In addition to cleaning the outside, wouldn't it be better to avoid the nozzle dip into the PVA prime blob at the the beginning of the print?

I like the prime blob, for me it's an easy way to flush out degraded/other material quickly before a print. But I think there is more reasons why material builds up underneath the nozzle, you will also see it happening when printing overhangs and when the first layer isn't printed perfectly.

[nallath 1,120]

What's your favourite Cura setting? Why?