Which filament to use for strength?  

  RSS
Roger
(@roger-4)
Active Member

I need to print durable mechanical parts, specifically I'm interested in high impact resistance and low deformation, even with thinner parts. The material needs to be printable safely with an MK3S.

 After doing some reading, it seems my options are PC and nylon. I also considered ASA/ABS, but it seems it's heat-resistant rather than mechanically strong. 

So, should I try PC or nylon? Is prusa PC blend as strong as regular PC? Is nylon really flexible or can thin (2-3mm) parts be rigid?  Is there a soluble filament that can be used as support when printing PC? Is there another option I'm not considering?

Also, I'm planning to build an enclosure and a humidity-controlled box for the filament, will that be enough or do I need something else?

Posted : 27/11/2020 7:09 pm
Lvet
 lvet
(@lvet)
Estimable Member

I didn't perform any accurate mechanical strength comparison, but PC beats totally Nylon in terms of ease of printing.

Nylon is even more hydrophilic than PC and in order to print with a decent quality you will need to place the spool in a filament dryer.

For both an enclosure for the printer will help greatly. 

I don't have any experience with PC and soluble supports. But I would be interested to know as well.

Posted : 27/11/2020 8:25 pm
Lvet
 lvet
(@lvet)
Estimable Member

Just to add. Have a look at these two tables:

https://www.simplify3d.com/support/materials-guide/properties-table/

https://help.prusa3d.com/en/materials

According to Simplify3d Nylon is easier to print than PolycaCbonate. In any case different additives that manufacturers add to the materials allow printing with lower temperatures. Note that Nylon's Coefficient of Thermal Expansion is pretty high making warping a constant problem.

Posted : 28/11/2020 4:16 am
jsw
 jsw
(@jsw)
Noble Member

I have never printed with nylon, but I have printed with Prusa's PC Blend and it's quite strong and relatively easy to print.  The only thing you really need to be sure of is to use a release agent.

I know that nylon will stretch, so I assume it will readily flex as well.

Posted : 28/11/2020 4:59 am
Swiss_Cheese
(@swiss_cheese)
Reputable Member

I believe lvet meant to say, " hygroscopic" and roger-4 you will definitely need a way to dry those filaments, a dry box will not dry wet filament, it will only keep the moisture at bay after the filament is dry, that's assuming you keep your desiccant fresh, it takes heat to release the moisture that the filament will absorb from the air.

Nylon isn't so much flexible as it is bendable, it's NOT like TPE's or TPU, (in general though it is considered flexible) it works great for gears and can be used structurally no problem, if you design well. as well their are versions on the market that have carbon fiber in them and also fiberglass, that does a very nice job of stiffening it up with very minimal loss of strength. I have printed both the Nylon X and the Nylon G and was not disappointed. Nylon is so strong we don't really consider the loss from the fiber impregnation. You will see a much stiffer part if printing with Nylon G or X or some product like it.

I have never printed Prusa PC Blend, but I keep hearing good things about it.

you might be surprised at what you can do with ABS and ASA they are very handy and cost effective plastics, don't write them off. 

Good luck and enjoy

Posted : 28/11/2020 7:23 am
Lvet
 lvet
(@lvet)
Estimable Member

Hi @swiss_cheese,

You are perfectly right, " hygroscopic" is the right term. "hydrophilic" has a different meaning (Nylon and many other polymers can be both hygroscopic and hydrophilic). 😉 

Posted : 28/11/2020 2:26 pm
karl-herbert
(@karl-herbert)
Famed Member
Posted by: @roger-4

I need to print durable mechanical parts, specifically I'm interested in high impact resistance and low deformation, even with thinner parts. The material needs to be printable safely with an MK3S.

 After doing some reading, it seems my options are PC and nylon. I also considered ASA/ABS, but it seems it's heat-resistant rather than mechanically strong. 

So, should I try PC or nylon? Is prusa PC blend as strong as regular PC? Is nylon really flexible or can thin (2-3mm) parts be rigid?  Is there a soluble filament that can be used as support when printing PC? Is there another option I'm not considering?

Also, I'm planning to build an enclosure and a humidity-controlled box for the filament, will that be enough or do I need something else?

This material has good mechanical properties, is more heat resistant than ABS or ASA after tempering and is easy to print (260/90):

https://3dk.berlin/de/3dktop-hitzebestandig/195-3dktop-schwarz-hitzebestandig-bis-230c.html

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen....
Posted : 28/11/2020 2:38 pm
cwbullet
(@cwbullet)
Famed Member

I have printed a few rolls of3DXTech’s Nylon CF.  It is pretty tough stuff.  

--------------------
Chuck H
3D Printer Review Blog...
Posted : 28/11/2020 6:01 pm
karl-herbert
(@karl-herbert)
Famed Member

@cwbullet

I often use it, but a print with a nozzle smaller than 0.40mm has not yet succeeded. Therefore I use this material rather for medium to large parts. The printed parts are extremely tough and resistant.
The best results are achieved by printing with my favorite TC 👍 

 
This post was modified 2 months ago 2 times by karl-herbert
Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen....
Posted : 28/11/2020 7:20 pm
cwbullet
(@cwbullet)
Famed Member

@karl-herbert

Good point.  I have used 0.8 and I think 0.6mm.  I forgot to add that.  

--------------------
Chuck H
3D Printer Review Blog...
Posted : 28/11/2020 9:13 pm
Roger
(@roger-4)
Active Member

Thanks all for the info!

Posted by: @lvet

Just to add. Have a look at these two tables:

https://www.simplify3d.com/support/materials-guide/properties-table/

https://help.prusa3d.com/en/materials

According to Simplify3d Nylon is easier to print than PolycaCbonate. In any case different additives that manufacturers add to the materials allow printing with lower temperatures. Note that Nylon's Coefficient of Thermal Expansion is pretty high making warping a constant problem.

It seems regular PC is even more difficult to print than nylon, but prusa pc blend is easier?

 This is why I stopped considering ASA/ABS: according to the figures PLA and PETG are stronger than them, but I can easily break objects made of either.

 

 Well, I have even more options now, I'm gonna have to think about it. I wish we could get samples, a couple of meters, so we can test materials. I can't really buy 4 or 5 40-50€ rolls just for testing.

Posted : 28/11/2020 10:22 pm
karl-herbert
(@karl-herbert)
Famed Member

@roger-4

Maybe you will find something suitable here: https://www.matterhackers.com/3d-printer-filament-compare

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen....
Posted : 28/11/2020 11:46 pm
Swiss_Cheese
(@swiss_cheese)
Reputable Member

PLA is quite strong and stiff if it wasn't for it's poor thermal properties (it has a low vicat temp) and inability to keep its shape under prolonged stress it would be much more useful. PLA does not break easily. (Note some PLA's preform better then others)

PETG on the other hand will shatter into pieces under even low impacts even though it is more bendable and it tends to break across the layers and not with them it has great layer adhesion, it has an Ok vicat for things like gears and is good in non impact applications like ras Pi cases. (Note some PETG's preformed better then others, but they all shattered) 

ASA and ABS have reasonable, completely usable qualities from a mechanical, structural and thermal point of view, as I said before don't count them out, they are very useful plastics. (Note some ABS's & ASA's preform better then others) <--are you starting to see a recurring thyme?

If your making bicycle parts, skateboard trucks or parts for off road use, then IMHO just go straight for the nylon products, no matter what you choose your are going to have to learn how to print it, so don't let folks saying it deforms or its hard to print scare you away from a product, try it for yourself and learn.

Just before I typed this post I jumped on line and ordered more ASA and I ordered a roll of the Prusa orange PC Blend,  I'll let you know how it goes, the only polycarb I've worked with to date was cut by us or ordered to suit, this will be my first time printing it, however I'm not expecting a problem, and I will be testing its properties.

Also as a general rule good filaments aren't cheap, just keep that in the back of your mind.

This post was modified 2 months ago 2 times by Swiss_Cheese
Posted : 29/11/2020 12:42 am
Share:

Please Login or Register