chemical resistance of the filaments

[Pepa 0]

We need to make some pieces for our laboratory that can be cleaned with organic solvents.
Where can I find truthful information about the resistance of the various filaments to these solvents?
The ideal would be in Nylon but we need to know if we can use other materials easier to print than Nylon.
We have printed on Nylon but it still gives us warping problems. We print it in the UM3Extended. It has a door and lid and we pre-dry the Nylon and the PVA in the stove at 60º.
During printing we cover the printer with a thermal blanket to avoid currents and temperature changes. Thanks in advance

[SandervG 1,521]

Hi @Pepa, thank you for your message and welcome to our community! 

Can you elaborate a bit on which organic solvents you want to use? Or will it vary a lot?

 

CPE and CPE+ are both chemically resistant. Have you considered any of these materials?

When you say you want to use other materials which are easier than Nylon, what is it about Nylon that you are having difficulties with?

Just warping? Do you use the active leveling? Do you have a clean build plate? Do you use Ultimaker Nylon or third party Nylon? 

 

Looking forward hearing from you!

[kmanstudios 1,120]

Covering the top with a thermal blanket seems like it would put undue pressure on the bowden tubes and create feed issues. Unless they are supported by some sort of structure; hanging or otherwise.

[Dim3nsioneer 557]

Unfortunately, Ultimaker could not provide specific information about chemical resistance (something like a list of acids etc.) until about two months ago. Maybe this has changed in the meantime.

For the PP it's pretty easy to find information just by Google. With Ultimaker Nylon and CPE/CPE+ it's more tricky as those materials are blends. So it would require information from the production partner.

 

I would recommend to get in touch with your Ultimaker reseller and ask for a few pieces of those materials so you can test it in your lab for your specific application. This is probably the safest way to find out if they are suitable for you or not.

[Pepa 0]

22 hours ago, SandervG said:

Hi @Pepa, thank you for your message and welcome to our community! 

Can you elaborate a bit on which organic solvents you want to use? Or will it vary a lot?

 

CPE and CPE+ are both chemically resistant. Have you considered any of these materials?

When you say you want to use other materials which are easier than Nylon, what is it about Nylon that you are having difficulties with?

Just warping? Do you use the active leveling? Do you have a clean build plate? Do you use Ultimaker Nylon or third party Nylon? 

 

Looking forward hearing from you!

Thanks for your reply. The Nylon we have used is from the ULTIMAKER brand. Our piece was a cell with an interior coil.
The printing lasted five days and was 100% filled
We print the same with Nylon and PVA, at the temperature of the printing plate and the extruder recommended by CURA.
We used automatic active leveling and the build plate was clean. Our printer is closed.
As we had problems with the warping, we reduced the speed of printing, turned off the ventilation and covered the printer with an emergency blanket used in the mountains to avoid fluctuations in temperature and humidity at night.
Preva to the impression we heat in stove in Nylon (to 60º, three minutes) and the PVA.
The result was acweptable but the piece was a size of 10x13x1.5 cm. It came out a little warped.
Regarding the solvents with which we have to work are preferably chloroform, ether, ethanol and acetone.
Just today we are testing the CPE. The CPE + is not valid because it does not support PVA. We hope you do not give us as many problems as Nylon.

[Pepa 0]

12 hours ago, kmanstudios said:

Covering the top with a thermal blanket seems like it would put undue pressure on the bowden tubes and create feed issues. Unless they are supported by some sort of structure; hanging or otherwise.

Thanks for your reply. The blanket we use is of negligible weight. It's made of aluminum, used by emergency teams and in the mountains

[gr5 2,167]

I recommend you stick with nylon.  PVA works better with Nylon than many other materials.  Nylon is a fantastic material once you learn all the tricks.  I think instead you should concentrate on fixing the "warping" problems.  When you say "warping" do you mean the bottom layer is lifting at the corners?  If this is the only issue left then this is easily fixed.  Please show a photo of the issue you mean - your "warping" issue.

 

You use the blanked *during* printing.  Right?  You want the air temperature to reach about 35C.  If you have a temperature probe you can check the temperature of the inner side of the printer.

 

But this is only one of about 5 things you need to do for Nylon to stick well.  The quick version is: brim, rounded corners, squish extra well, very very thin liquid PLA on the glass, fan very low or off (3% max), clean all grease and dust off glass once per month and clean off soap also, cover front and top to get air to 35C.  I can elaborate on these after I know what you are already doing and what you mean by "warping".

 

Photographs please!

[Pepa 0]

On ‎4‎/‎26‎/‎2018 at 7:57 AM, Dim3nsioneer said:

Unfortunately, Ultimaker could not provide specific information about chemical resistance (something like a list of acids etc.) until about two months ago. Maybe this has changed in the meantime.

For the PP it's pretty easy to find information just by Google. With Ultimaker Nylon and CPE/CPE+ it's more tricky as those materials are blends. So it would require information from the production partner.

 

I would recommend to get in touch with your Ultimaker reseller and ask for a few pieces of those materials so you can test it in your lab for your specific application. This is probably the safest way to find out if they are suitable for you or not.

Thanks for your reply. Now we are testing various materials in our laboratory. On the one hand filaments and on the other printed pieces, since we think that the chemical properties are evident that change after the printing process. We will report the results.

[Pepa 0]

17 hours ago, gr5 said:

I recommend you stick with nylon.  PVA works better with Nylon than many other materials.  Nylon is a fantastic material once you learn all the tricks.  I think instead you should concentrate on fixing the "warping" problems.  When you say "warping" do you mean the bottom layer is lifting at the corners?  If this is the only issue left then this is easily fixed.  Please show a photo of the issue you mean - your "warping" issue.

 

You use the blanked *during* printing.  Right?  You want the air temperature to reach about 35C.  If you have a temperature probe you can check the temperature of the inner side of the printer.

 

But this is only one of about 5 things you need to do for Nylon to stick well.  The quick version is: brim, rounded corners, squish extra well, very very thin liquid PLA on the glass, fan very low or off (3% max), clean all grease and dust off glass once per month and clean off soap also, cover front and top to get air to 35C.  I can elaborate on these after I know what you are already doing and what you mean by "warping".

 

Photographs please!

Thank you for your response and for the indications you give us. Part of them we already tested, and we had not thought about the fine thin layer of PLA that suggests us. We have adhesion sheets but we are afraid not to be able to detach them from the glass afterwards. I attach the photos requested.

This is our piece. Inside has a coil where a fluid is going to circulate.

Here you can see the warping at the base of the piece,  and we need the piece to be totally flat. In the final model we solved it by passing it through a milling machine, since the warping was small. But it is evident that it is not always possible to do this.

[kmanstudios 1,120]

Do you have a copy of the file you could share? And for testing to make sure it is as comparable as possible, what specific material are you using?

 

[Pepa 0]

I will ask the user if it is possible to share the model. Regarding the material we use Nylo and PVA from Ultimaker

[geert_2 557]

Nylon for 3D-printing contains additives too. For example the UM-nylon becomes weak and gets a sort of "snot" feeling when put in water for some time. After drying it hardens again to its normal strong properties. I believe this is due to additives, since this is not standard nylon behaviour. Also, UM-nylon is transparent, while pure nylon usually is milky white. Usually it requires a lot of additives to turn non-transparent plastic into transparent.

 

You also have to keep in mind that 3D-printed models have little holes where the product will creep deeply into the material, and may affect long-term characteristics. (This is also true for bacteria and enzymes: they also get deep into the models, which may make cleaning and desinfecting difficult or impossible.)

 

So I think the only reliable way will be thorough testing indeed. Fill glass jars with your cleaners/desinfectants of choice, and put some complex testprints in it, with lots of little holes. Shake, and let them sit for a couple of weeks. Preferably at a slightly elevated temperature (just below softening temp of the plastic). And regularly inspect for damage.

 

Aceton is guaranteed to damage most plastics or additives. Xylene also (=commonly used in laboratories for parafine removal). But maybe isopropyl alcohol won't do too much damage? This is a standard hospital desinfectant, and a good grease remover.

 

ABS and polystyrene are going to be damaged by most solvents.

 

Pure PLA (without additives) seems to be more resistant to solvents than most other materials, and it is easy to print. At least I don't see any damage when cleaning with isopropyl alcohol and degreasers. Maybe PET and polyesters would also work (e.g.: colorFabb NGEN or similar)? These are all very easy to print without warping, and are reasonably strong and have good layer-bonding. So I would try them first.

 

PE and PP are most resistant, but difficult to print. But I have no idea if PE or PP filament for 3D-printing is pure without additives?

 

Depending on the "cleanness" you need, another option might be to redesign the part so that the majority of the part needs no cleaning at all, like any clamps and the base plate or so. And only a little part that comes into contact with samples needs cleaning or replacement. And then just print a new piece for each test. If this is just a thin plate or thin cup to insert into the rest, it takes very little material and time to print. This might be the cleanest way, if you handle the replacement parts with a tweezer (pincette) to avoid fingerprints. When freshly printed, they are desinfected by the +200°C nozzle temperature anyway.

 

Edit: your post with pictures crossed my one. So my last remark may be no longer valid. I wrote that with small biological samples in mind, like I have seen at my collegues' research.

 

Edited April 27, 2018 by geert_2

[kmanstudios 1,120]

55 minutes ago, geert_2 said:

For example the UM-nylon becomes weak and gets a sort of "snot" feeling when put in water for some time

I have actually annealed UM Nylon and it gets really tough when that is done. It was a very nontechnical experiment as I just threw it in the oven, but I am looking to do more controlled Experiments. UM Nylon, so far is my favorite nylon.

 

1 hour ago, Pepa said:

I will ask the user if it is possible to share the model

Fingers crossed :)

[Brulti 177]

Personal experience with UM-Nylon shows that it does tends to soften when put in water, did that quite a lot to get rid of PVA support on pieces I printed, but it usually gets back in shape and hardens once dry, without loosing it's mechanical properties.

 

As said aboive, brim or raft are mandatory for Nylon, the glass must be squeaky clean, and some glue can help, depending on the size and shape of the pice, as well as the print time. I haven't seen much of a difference with using a closed door or not though.

[geert_2 557]

It is hard to see the canals on the photo. But if I had to make such a thing for production runs, I would probably have it machined from solid blocks of nylon, PE, or PP, whatever is most appropriate for your application. This will be much stronger, easier to clean, have a smoother finish, and have a longer life. And then you can use known engineering materials. Sealing of multiple parts could be done by making a seal from solvent-resistant automotive silicone, if you design a canal in the edge where the silicone can go, prior to closing the halves. And design holes for screws and nuts. Most research labs and universities have access to a workshop with CNC machines and qualified operators. Then I would just use 3D-printing to test the concept, prior to having it machined.