Oil In Print When Using Nylon

[Sbanman 0]

We have recently purchased a 3 Extended to run one of our production parts on. The part we are running is a two color part. We are using black nylon(most of the part is made from this) for one of the colors and white PLA for the other. In the last week or so we have all of the sudden been having issues with he part sticking to the print plate. Ever time i would pull it up i would notice something that looked like oil on the plate. I would clean it and reset it and then try again. But today when I noticed the print had failed There was just a puddle of oil where the nylon purge should be and another one were the print normally starts. See Pictures. The parts are big and take about a half a spool to do and about 2 days to run and we have been running them pretty much non stop for a month. I'm printing it at 255c and the build plate is set to 60c. Is this just a common issue after so many prints? Do i need to adjust my printing temps? Do I just need to clean it? Any input would be helpful.

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[kmanstudios 1,120]

Maybe a bad spool of material? I have not had this happen and my printer has been running for 7 months, almost non stop. While I do not use nylon all the time, it does get used.

Are you cleaning it properly and regularly?

[Labern 774]

Nylon absorbs a lot of water and quite quickly from humidity in the air. This when heated in the nozzle comes out like this oily looking stuff that you have noticed. In dryer climates this moisture takes longer to absorb into the filament compared to high humidity wet climates.

This can happen to me in a matter of days.

You need to dry the material. Keep it in a warm dry place. I seal mine in a container with desiccant to keep it dry. You can also heat it in an oven for 30min to 1 hour to dry it more quickly but don't heat it too much or the spool will deform.

[tomnagel 126]

I recently tried to dry a spool of Ultimaker Nylon in my oven set at 65 degC (checked with meat temperature sensor). It sat in the oven for 3 h, but it didn't help in getting the material to print well.

A colleague told me that part of this water can be chemically bonded. Then, drying is impossible.

This is all not scientifically proven, but my take was that it is really important to keep this stuff in a dry environment, similar to PVA.

Are you using Ultimaker Nylon? That is more resistant to ambient moisture than most available brands of Nylon filament. Up to 50-ish % I guess. Above that, things go south.

[Labern 774]

I have been able to get the moisture out of one roll 3 times but this was not using the oven method.

I actually dried PVA so much that it became really brittle and would break while trying to put it into the feeder.

But yes it can get to a point of no return.

[kmanstudios 1,120]

I have been able to get the moisture out of one roll 3 times but this was not using the oven method.

I actually dried PVA so much that it became really brittle and would break while trying to put it into the feeder.

But yes it can get to a point of no return.

 

So far, I have been lucky in that I have just been able to put it back into a drybox and let the desiccant do its job.

On a side note, I just finished a 5 day print job with tons of PVA. You can actually see the change in the PVA as time went on.

And, I had to really clean it out when done because of all the cooked moisture charring things up, inside and out.

Edited July 13, 2017 by Guest

[geert_2 557]

Normally nylon can easily be dried in an oven.

But I have the impression (this is a guess, not necessarily correct!) that nylon for 3D-printing sometimes contains modifiers to reduce moisture absorption, or to chemically bond it, or to mechanically bond it in the molecular structure (like the gels in pampers)? Maybe this could cause this?

Anyway, store all filament in a closed box, with a huge bag of disseccant (the sort with color indicator: blue=dry, pink=moist) that is also used to dry car interiors, and that can be dried in a microwave. For really sensitive materials, keep them in such a box while printing: make a spool holder in the box, drill a small exit hole for the filament, and place that closed box behind your printer.

[Sbanman 0]

Nylon absorbs a lot of water and quite quickly from humidity in the air. This when heated in the nozzle comes out like this oily looking stuff that you have noticed. In dryer climates this moisture takes longer to absorb into the filament compared to high humidity wet climates.

This can happen to me in a matter of days.

You need to dry the material. Keep it in a warm dry place. I seal mine in a container with desiccant to keep it dry. You can also heat it in an oven for 30min to 1 hour to dry it more quickly but don't heat it too much or the spool will deform.

 

I have the material that is open stored in a dry box with descant. But the material i am using to do these prints is straight out of the box and their vacuum sealed packs. I pull them out and put them right on the printer and start printing with it.

[Sbanman 0]

Maybe a bad spool of material? I have not had this happen and my printer has been running for 7 months, almost non stop. While I do not use nylon all the time, it does get used.

Are you cleaning it properly and regularly?

It has been happening with the last 3 spools. I Have a hard time believeing that I got 3 bad spools in a row. As for the cleaning is there really any way to clean it for this issue? I looked at how to clean the printer cores and its all for if they are clogged.

[Labern 774]

I have had a new roll with too much moisture and had to dry it before. I'm not saying it's the same in your case but it can still be an issue.

Are you using default temps and speeds?

[kmanstudios 1,120]

Maybe a bad spool of material? I have not had this happen and my printer has been running for 7 months, almost non stop. While I do not use nylon all the time, it does get used.

Are you cleaning it properly and regularly?

It has been happening with the last 3 spools. I Have a hard time believeing that I got 3 bad spools in a row. As for the cleaning is there really any way to clean it for this issue? I looked at how to clean the printer cores and its all for if they are clogged.

Depending on where you are in the US, there could have been a great increase of humidity. I know I am running into that issue here in Brooklyn. Even with my A/C running 24/7 it is having a hard time keeping the humidity down a bit. Like I said before, I just finished running a 5 day print and you can see the change in the PVA structure quite easily as the days wore on.

From what I understand, Nylon and PVA are pretty much the same level of being hygroscopic.