Anyone tried TPU or TPE filaments?

[Oliveros 11]

Hey Guys,

 

I was talking to a co-worker about printing and different filaments and he mentioned he had some TPE and TPU filaments which are essentially polyurethane but one is more rigid than the other one. 

 

I got to thinking if printing gaskets would be possible and for what? It seems it's resistant to oil and fuel but I'm thinking more in terms of service temp, could I print my own 2" dialectric union gaskets when one is leaking and it's 2 AM and no one else has one? would it hold up to 140*F water? 

 

Could be cool to be able to make my own electrical enclosures and then make a gasket for them as well.

 

Anyone have any experience with these?

[geert_2 557]

I think they are going to be too stiff. And blobs, irregularities and print lines are not going to help making it water-tight. Unless you would squeeze it extremely hard between thick steel flanges. If you don't want to store gaskets, or originals can not be found anymore, I think you would be better off cutting new gaskets from a sheet, with a knife or a Dremel tool? Or use self-curing silicone or similar paste?

 

For comparison: transparent PVC tubing for aquariums is much softer than TPU. But when I tried to use that recently to make a seal for my water-cooled disk grinder, I had a lot of problems getting it water-tight. Even the slightest amount of corrosion and oxidation on the surface of the metal, caused leaks. So, even soft PVC is not flexible enough to follow these tiny irregularities and close the gaps.

 

But if you would try it anyway, let us know the result. It would be interesting to know.

 

[Oliveros 11]

Okay cool, good to know.

 

I'll probably give it a shot and see, after some googling it seems that it COULD work, but it might not work as you are describing. 

 

Perhaps it could work for making water tight gaskets for enclosures, maybe not for pressurized applications.

[Elfonerio 5]

I just tried a gasket with Ultimaker's TPU (BLACK) and it worked.  The material doesn't like to bridge all that well, but it printed really nice on the S5.  The gasket will be used for a junction box we use at work, which doesn't have to be an awesome seal, just enough for splashing.  I can't really test it underwater because the enclosure itself is full of holes.  But just from my experience I would say this would be water tight in an application where there is enough clamping force throughout the gasket surface (I light smear of silicone would also seal the deal).  The pliability of this stuff is great, it seams tough too, I am sure I will find new uses for this now that I have tried it.

 

Next print I will try "enable ironing"  for a smoother top layer.

 

-Jared

 

 

[Oliveros 11]

Awesome, thank you for sharing that.

 

I'm going to try to make a strain relief today for a cord and see how it works.

[Oliveros 11]

Well, 

 

I ended up using Ninjatek Armadillo since the Ninjaflex wouldn't feed.

 

Turned out okay, not as flexible as I wanted but probably enough.

[jbearpark 0]

I've printed some parts in TPU-95a recently and the key thing I would say is make sure it is robust design and limit thinner sections. It has a hard rubbery feel which is nice but doesn't offer a huge amount of strength. I also found it can come out a bit messy but tidies up well. Definitely has a niche use (I made the outside of a handle from it, but it needed a rigid piece inside to keep its shape. 

Despite UM saying it is experimentally compatible with PVA, I had no issues printing support structure. If you have dual extrusion it works really well and is pretty easy to separate without having to dissolve the most of the PVA.

[AndersK 59]

Yesterday I printed a sealing plate where the seal is  tpu  and the shell carbon fiber reinforced PETG. Pressure tested up to 5 MPa hydraulic pressure. I was surprised how well it worked.

 

The PETG and TPU bonded really strong.

Edited January 16, 2020 by AndersK
bloody autocorrect....

[Oliveros 11]

Cool. So I guess it's possible to print gaskets.

 

So you printed the seal or gasket out of TPU correct?

[AndersK 59]

Yes

Not the best finnish , still learning and trying settings for TPU.

 

[P3D 46]

About TPU printing quality/finish... we learned the hard way that TPU is quite hygroscopic and won't print well when wet. (Hard way == Ultimaker having had rubbish packaging, putting the TPU in shrinkwrap with lots of holes instead of a proper vacuum packaging). So if you're not satisfied with TPU print results, try drying the filament and see if that helps.

[Oliveros 11]

Wow, that looks good.

 

What's the temp rating of TPU in general? Any good for hot water?

[AndersK 59]

Thank you.

Continuous working temp is 110°C so hot water should be ok. Guess it will soften a fair bit so pressure need to be at moderate level.

[Oliveros 11]

Very cool.

 

My Monoprice Ultimate 2 wouldn't print ninjaflex since I guess the filament just wrapped up inside the gear so I'll have to mod it if I want to be able to do TPU.

[AndersK 59]

On 1/21/2020 at 9:13 AM, P3D said:

About TPU printing quality/finish... we learned the hard way that TPU is quite hygroscopic and won't print well when wet. (Hard way == Ultimaker having had rubbish packaging, putting the TPU in shrinkwrap with lots of holes instead of a proper vacuum packaging). So if you're not satisfied with TPU print results, try drying the filament and see if that helps.

 

Good point. Learned that, also the hard way, when starting with Nylon. The sound of frying bacon makes you hungry 😉

 

Currently Im lucky having about 30-35% humidity so should be ok.

Also my material comes in vacuum sealed bags and it was fresh when I printed my parts.

Next time I'll  run two pieces and dry the material between prints to se if theres a difference.