<p>It's very difficult to get accurate internal sizing with 3D printing for this sort of application. It's also difficult to get it airtight without some sort of post-processing. My group wrote a <a href="https://threedmedprint.biomedcentral.com/articles/10.1186/s41205-021-00129-1" rel="noreferrer">paper on the flow dynamics of pressure restrictors made with 3D printing</a>. In short, I'd suggest you use a drill or mill to produce such parts. We were using pressures &lt; 0.1bar and still struggled to get them to seal without post-processing.</p>

CC BY-SA 4.0
2022-08-28T19:11:07.407Z
2022-08-28T19:11:07.407Z
fifteenforty
<p>This is going to be hard. Even holding a vacuum is hard (I've tried it and not succeeded). I'm not sure what the mechanism of air molecules getting thru the print is - whether it's defects in inter-layer bonding, defects at seams, imperfect mating with the fitting, or even permeability of the plastic itself. It might not actually be existing flaws in the print, but rather the high pressure being a stronger force than the bonded layers can withstand, essentially ripping the layers apart from the weakest point until the pressure can discharge through the opening produced.</p>
<p>If using ABS, you might try an acetone bath followed by a long period of trying or use of vacuum chamber to quickly remove the solvent, if you can stand some possible part deformation. This would tend to fill any gaps. Coating with low-viscosity CA glue (Loctite 420 or equivalent) might be a better version of this approach, as the solvent will both attack the ABS and deliver fill material.</p>
<p>In principle PET (maybe also PETG, but PET is preferable anyway if you can get it) should be a suitable material for pressure vessels, as it's what's used for soda bottles at comparable pressure, but those are blown from a single piece, not fused together with seams.</p>
<p>At some point I will attempt this again, and will update my answer if I have any findings that contribute to your question.</p>

CC BY-SA 4.0
2022-08-29T14:24:24.473Z
I also thought about PETG for my similar part, I discarded it because of possible deformation due to creep and resulting leakage. It could be interesting to try PET. Maybe PP too? it is said to have perfect layer adhesion
FarO
CC BY-SA 4.0
2022-08-30T13:45:07.853Z
I find PETG a lot more less prone to deformation than ABS,   ABS is absolutely a nightmare to print, if you do not have an enclosure, forget about ABS.   The key with PETG is to print with a bed of around 90 degrees will mitigate warping, and printer around 250 degrees for this particular application. Switch fan off.  It can also help when printing it fast.  XTC-3D epoxy treatment and heat treatment will help too.
Glenn Plas
CC BY-SA 4.0
2022-09-01T17:21:23.787Z
"a lot more less prone"? That's... confusing at best. Is it "a lot more prone" or "a lot less prone", or is there some specific meaning to "a lot more less prone" that I'm not familiar with?
FreeMan
CC BY-SA 4.0
2022-08-28T16:49:33.820Z
2022-08-28T16:49:33.820Z
R.. GitHub STOP HELPING ICE
<h2>Not without postprocessing</h2>
<p>FDM is pretty much welding plastic to plastic. Many many layers. Each of them is a potential breaking point, a corner for stress to arise and break the print.</p>
<h2>Easy with a hollow body</h2>
<p>Printing a hollow item that can be filled with resin is comparatively easy. Once filled with a monolithic curing resin (epoxy), that will take the pressure much better and seal it fully.</p>

CC BY-SA 4.0
2022-08-30T12:20:32.877Z
2022-08-30T12:20:32.877Z
Trish
<p>I want to make some prints of pressure resistants. I am currently trying to print a simple cylinder to find the best parameters to make my prints airtight (by airtight I mean, it needs to resist to 10 bar).</p>
<p>Here is the test model that I have made for this:</p>
<p><a href="https://i.sstatic.net/IQyNO.png" rel="nofollow noreferrer" title="Screenshot of a model for a pressure resistant"><img src="https://i.sstatic.net/IQyNO.png" alt="Screenshot of a model for a pressure resistant" title="Screenshot of a model for a pressure resistant" /></a></p>
<p>Here are the parameters that I have changed in Cura:</p>
<ul>
<li>layer height: 0.1 mm</li>
<li>infill : 100 %</li>
<li>print temp: 250 °C (high temp to make the layers stick between them)</li>
<li>wall line count: 5</li>
<li>infill overlap: 40 %</li>
<li>flow: 115 %</li>
</ul>
<p>But all these changes in Cura don't give good results for ABS. It's not even airtight at 2.5 bar:</p>
<p><a href="https://i.sstatic.net/rt0B8.jpg" rel="nofollow noreferrer" title="Photo of pressure resistant under water producing bubbles; not airtight"><img src="https://i.sstatic.net/rt0B8.jpg" alt="Photo of pressure resistant under water producing bubbles; not airtight" title="Photo of pressure resistant under water producing bubbles; not airtight" /></a></p>
<p>And here is a mid-cut of the print :</p>
<p><a href="https://i.sstatic.net/EkNP6.jpg" rel="nofollow noreferrer" title="Photo of pressure resistant cut in two to show internal structure"><img src="https://i.sstatic.net/EkNP6.jpg" alt="Photo of pressure resistant cut in two to show internal structure" title="Photo of pressure resistant cut in two to show internal structure" /></a></p>
<p>Do you have any ideas/suggestions to have better results? Can it be from the ABS itself? There is a sort of white powder between the layers, is this normal for ABS? Should I try using PETG? What could I change in my parameters?</p>

CC BY-SA 4.0
2022-08-29T14:23:05.523Z
If it is ABS, have you tried acetone smoothing? I also cannot get plain ASA to be watertight at 2 bar...
FarO
CC BY-SA 4.0
2022-08-31T20:33:33.013Z
140psi is... it's a lot. Not that it will be impossible, but it might take a LOT of plastic.
Joel Coehoorn
CC BY-SA 4.0
2022-09-02T13:35:55.183Z
100% fill means no tolerance to overextruding. There is no hollow space to dispose of the overextruded filament.
Perry Webb
<creality-ender-3><abs>
Make a 3D print airtight 10 bar (140 psi)
Zylar
# Make a 3D print airtight 10 bar (140 psi)

(Asked by: username_0 on 2022-08-28)

I want to make some prints of pressure resistants. I am currently trying to print a simple cylinder to find the best parameters to make my prints airtight (by airtight I mean, it needs to resist to 10 bar).

Here is the test model that I have made for this:

[![Screenshot of a model for a pressure resistant](https://i.sstatic.net/IQyNO.png "Screenshot of a model for a pressure resistant")](https://i.sstatic.net/IQyNO.png "Screenshot of a model for a pressure resistant")

Here are the parameters that I have changed in Cura:

* layer height: 0.1 mm
* infill : 100 %
* print temp: 250 °C (high temp to make the layers stick between them)
* wall line count: 5
* infill overlap: 40 %
* flow: 115 %

But all these changes in Cura don't give good results for ABS. It's not even airtight at 2.5 bar:

[![Photo of pressure resistant under water producing bubbles; not airtight](https://i.sstatic.net/rt0B8.jpg "Photo of pressure resistant under water producing bubbles; not airtight")](https://i.sstatic.net/rt0B8.jpg "Photo of pressure resistant under water producing bubbles; not airtight")

And here is a mid-cut of the print :

[![Photo of pressure resistant cut in two to show internal structure](https://i.sstatic.net/EkNP6.jpg "Photo of pressure resistant cut in two to show internal structure")](https://i.sstatic.net/EkNP6.jpg "Photo of pressure resistant cut in two to show internal structure")

Do you have any ideas/suggestions to have better results? Can it be from the ABS itself? There is a sort of white powder between the layers, is this normal for ABS? Should I try using PETG? What could I change in my parameters?

**Tags:** creality-ender-3, abs
> **Comments:**
> **username_1**: If it is ABS, have you tried acetone smoothing? I also cannot get plain ASA to be watertight at 2 bar...  
> **username_2**: 140psi is... it's a lot. Not that it will be impossible, but it might take a LOT of plastic.  
> **username_3**: 100% fill means no tolerance to overextruding. There is no hollow space to dispose of the overextruded filament.  

---

## 3 answers

### Answer by username_4 on 2022-08-28. Score: 5

It's very difficult to get accurate internal sizing with 3D printing for this sort of application. It's also difficult to get it airtight without some sort of post-processing. My group wrote a [paper on the flow dynamics of pressure restrictors made with 3D printing](https://threedmedprint.biomedcentral.com/articles/10.1186/s41205-021-00129-1). In short, I'd suggest you use a drill or mill to produce such parts. We were using pressures < 0.1bar and still struggled to get them to seal without post-processing.


---

### Answer by username_5 on 2022-08-28. Score: 3

This is going to be hard. Even holding a vacuum is hard (I've tried it and not succeeded). I'm not sure what the mechanism of air molecules getting thru the print is - whether it's defects in inter-layer bonding, defects at seams, imperfect mating with the fitting, or even permeability of the plastic itself. It might not actually be existing flaws in the print, but rather the high pressure being a stronger force than the bonded layers can withstand, essentially ripping the layers apart from the weakest point until the pressure can discharge through the opening produced.

If using ABS, you might try an acetone bath followed by a long period of trying or use of vacuum chamber to quickly remove the solvent, if you can stand some possible part deformation. This would tend to fill any gaps. Coating with low-viscosity CA glue (Loctite 420 or equivalent) might be a better version of this approach, as the solvent will both attack the ABS and deliver fill material.

In principle PET (maybe also PETG, but PET is preferable anyway if you can get it) should be a suitable material for pressure vessels, as it's what's used for soda bottles at comparable pressure, but those are blown from a single piece, not fused together with seams.

At some point I will attempt this again, and will update my answer if I have any findings that contribute to your question.

> **Comments:**
> **username_1**: I also thought about PETG for my similar part, I discarded it because of possible deformation due to creep and resulting leakage. It could be interesting to try PET. Maybe PP too? it is said to have perfect layer adhesion  
> **username_6**: I find PETG a lot more less prone to deformation than ABS,   ABS is absolutely a nightmare to print, if you do not have an enclosure, forget about ABS.   The key with PETG is to print with a bed of around 90 degrees will mitigate warping, and printer around 250 degrees for this particular application. Switch fan off.  It can also help when printing it fast.  XTC-3D epoxy treatment and heat treatment will help too.  
> **username_7**: "a lot more less prone"? That's... confusing at best. Is it "a lot more prone" or "a lot less prone", or is there some specific meaning to "a lot more less prone" that I'm not familiar with?  

---

### Answer by username_8 on 2022-08-30. Score: 2

## Not without postprocessing

FDM is pretty much welding plastic to plastic. Many many layers. Each of them is a potential breaking point, a corner for stress to arise and break the print.

## Easy with a hollow body

Printing a hollow item that can be filled with resin is comparatively easy. Once filled with a monolithic curing resin (epoxy), that will take the pressure much better and seal it fully.


---

