FDM printing Nitrile (Buna-N) rubber?

[Scott_Curtis]

3D printing newbie here; please be gentle as I ask stupid questions…

Has anyone tried printing Nitrile rubber (Buna-N) through a FDM printer? I’m using an Airwolf Axiom Dual head. Haven’t tried it yet, but my boss has asked if it is possible. I don’t want to totally much up the print head “experimenting”, so thought I’d ask here. Basically, what I’m wondering is whether or not it’s possible to feed Buna-N o-ring cord stock, i.e. will it melt properly, etc.

Thanks in advance!

[Robert_57]

Never tried, but it would be great for printing O-rings in place. Maybe try heating up the hot end and touching some to the outside of the heater block? If it melts and flows great, if it doesn’t or burns, experiment over

I’d be interested to hear how you go though.

Rob.

[Garyg]

Hi

Buna-N material is very low cost and most common used sealing rubber.

It does have problems depending on the application.

If you take a look at specifications for Buna-N and NinjaFlex 3D printing material you might find it interesting.

NinjaFlex material is a bit peculiar to print, but lately I’ve been quite impressed with it.

I’ve had trouble with sunlight degrading Buna-N material.

My NinjaFlex parts appear to be holding up with large exposure to sunlight.

I’ve had trouble with Buna-N material getting brittle when exposed to gasoline fumes.

So far, my latest small project with Ninjaflex has held up to gasoline fumes - the test is ongoing and only 8 weeks running.

I know that this is not the answer to your question, but I could not resist chiming in.

I’m for sure on a quest to eliminate my Buna-N problems.

I hope this helps you in some manner.

[federico3]

@Airwolf3D might you be able to help @Scott_Curtis?

Federico

[Scott_Curtis]

Thanks Gary! As I mentioned in my initial post, we’re just getting our feet under us on the road to being 3D printing proficient, so I appreciate any wisdom you can impart!

Our situation with the Buna-N requirement is unique in that we are a contract manufacturer, so we (for the most part) have to use the materials of construction specified by our customers. I had taken note of the NinjaFlex material, but could not tell how closely it’s material properties aligned with the Buna-N. Sounds like it would be worth blowing a few buck on a spool of filament to give it a try though.

[Scott_Curtis]

I’m chasing that rabbit down it’s hole as well; most of the printer manufacturers tend to be reluctant about providing guidance on print materials they are unfamiliar with. I guess that’s fair though; they don’t want to take a chance on being blamed for either damage to a printer, or loss caused by a printed part that failed.

I will post whatever feedback I receive from Airwolf here for others to share.

[Enza3D]

Hey Scott!

As a fellow Axiom owner, printing anything flexible with the Axiom is a bit of a pain. Because of the way the printer is designed the filament has to be pushed through a decent amount of tubing before it reaches the hot end, and that path is difficult for filaments that flex to traverse. It’s a problem that plagues all Bowden style printers, but it isn’t insurmountable.

I haven’t tried Ninjaflex in mine yet, but I’ve yet to get a successful print with the TPU from Airwolf (which is similar to NinjaFlex in terms of plastic behavior). It took 5 or so tries to get the filament properly loaded (it kept trying to fold over itself in the feed tube). As for the actual printing, I’ve gotten close to a successful print by turning off all retraction and printing at around 15 mm/s, but the nozzle got clogged about 90% of the way throug the print. Anything faster than that is causing clogs and stripped filament in the extruder. So don’t get frustrated if you have a lot of problems with flexible filaments, it’s really common with the Bowden style printers!