Nylon printing.

So I've been trying to print with taulman 618 nylon and have gotten some less than stellar results and I wanted to hear from someone who has more experience printing with this material. First off, I'm using blue painter tape on a cold printbed which the nylon sticks to just fine as long as I make my bed height low enough so that isn't my issue (yet). My issues are:

• Excessive moisture (like wow, I can't believe how much mosture this stuff absorbs when in a sealed plastic bag)
• Retraction is almost useless, I've actually taken to just turning retraction off and that seems to have helped, but oh damn the stringies.
• The final print has a "musty" smell to it which the original filament does not have. It's unpleasant to say the least.
• Black, burnt blotches appear in the print (could be gunk picked up from my nozzle, but I don't think so)
• Final print breaks apart easily, unlike the strength this material is supposed to have

I'm printing with an E3D hotend at 245C and I've been printing ABS and PLA with this hotend for some time now without issue. Would drying the filament solve most of my issues? I've read that the moisture has no affect on the final print, but after seeing my results I'm not so sure. Any opinions from someone more experienced with this materal would be welcome.

I have tried trimmer line, not taulman's nylon, but most of the results are similar to what you see.


Lots of stringing (it seems nylon is very liquid when melted).
Tons of puffing due to moisture - I have let that filament in a sealed box with a couple of kilogrammes of rice for more than 2 months and it still hasn't dried perfectly, I might try drying in an owen next.
The smell while extruding is reminding me of lemon, but more the artificial junk food sweets smell - somewhat chemical. The printed part keep that smell, only less intense.
Warps a lot - really a lot. Seems to warp less after drying in rice, so removing moisture might help here. Successful adhesion achieved on kapton covered heated bed (110 °C) with an application of UHU (Elmer's glue for US people I believe) stick glue.


On the other hand my prints are very strong, it's impossible to make the layer detach. I've read somewhere on the forums that thinner layer heights improve layer adhesion for nylon.

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

Nylon of any sort is highly hygroscopic, far more so than most plastics. You can do a lot of damage to a nylon bolt by drying it out. I suspect that you will need an oven to get it dry enough to print with.

Do you know if it's safe to put the plastic spool it comes wrapped on in the oven? I'll probably bake it and then put it in a sealed tupperware container with some damp rid. I've heard others say that the moisture doesn't negatively affect the final print quality, but I'm not so sure.

You don't want to get any of this stuff really hot. 100 C is hotter than you should need to go. If you go to high, the filament will soften and you will have a fun time getting it off the spool. A 75C oven for 4 to 8 hours should dry things out pretty well (unless you live in a swamp ... ). Try the process with a couple feet of filament first. The stuff will gets quite stiff and brittle when it's fully dried out.

Edited 1 time(s). Last edit at 12/18/2013 09:11PM by uncle_bob.

>unless you live in a swamp

Well, I live in Florida so that's not too far off. Anyway, I have a bit of it (not the whole spool) in the oven now at 180F (82C). The oven now has that faint musty smell of printed nylon (although the nylon hasn't melted, it's warm but not melted or sticking). I'm hoping that smell will go away once the moisture is driven off. We'll see.

How did things turn out?

I've printed some bushings to replace the LM8UUs on the Z axis of a couple of machines. The seem to work nicely, even though the nylon had not been tried out.

BTW, I never trust the temperature readings on the common variety ovens, they can be off quite a bit.

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Yvan

Singularity Machine

One "interesting" approach to drying - haunt the garage sales looking for electric powered meat smokers. They will run at the right sort of temperatures and are set up for outdoor use. They have plenty of racks for filament in them and nice adjustable vents .....

@uncle_bob, you gave me an idea, try using a crock pot, or a table top roaster.



If you have some coin to spend this would be the ultimate:
($1100,00 used) VWR Shell -Lab 1410 Tabletop Vacuum Chamber Oven

Edited 1 time(s). Last edit at 12/19/2013 06:53PM by A2.

Does the vacuum chambre help a lot? I've been searching for years for an excuse to build one....

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Yvan

Singularity Machine

@Yvan,

A tabletop vacuum chamber oven would be uber geeky cool.
Yes, a vacuum + heat will pull out the moisture faster.

It would be interesting to place a 3d plastic filament printer inside of it,
and then pump in some argon or nitrogen gas

I think you could do a pretty good job on the vacuum with a simple diaphragm pump like the HIVAC guys use. Don't worry about the fancy gas backfill. Just warm it up and pump it down. Anything that's reasonably tight and big enough should work as a container. We used to do that sort of stuff in paint buckets. They looked just like the containers they use on paint shakers at Home Depot. Weather they were the same or not - no idea.

I find that nylon must be dry to get any good results, and you have to pretty much dry it every day if your print with it everyday and leave the stuff out like me, here in Australia-QLD seems to be a lot of moisture in the air, wish I lived in a dry climate

I would not waste the electricity/filament printing when it has not been dried,

- it looks bad and is brittle as hell from poor bonding layers


I actually dry small amounts in the oven for about 2 hours at close to 100c, if you dry it to high of a temp, it will also discolour.. I did once purposely do this for a bone print, gave it an authentic look of an aged fossil..
I wont print if I see any steam coming from the hotend anymore.. like maybe a tiny but less is better..

If your using trimmer line, it wont smell as bad once its dried as well I found.


Been using a cold bed, Spraying contact adhesive " kwik grip" letting it dry for 20 mins and then printing it... found I can print on that surface about 3 or 4 times b4 I need to reapply, but it works well to stop the warping when using a brim, but still get small warp... " make sure you don't get this on the rods, it will cause you a headachee"




an example I had was when I was building my quad copter, I had printed arms, printed them with non dried nylon, they broke on 10+ meter crashes, not all the time but some of the time, Since drying it, I have crashed 100's of times and no breaks, I have a hard time breaking them in my hands as well...

Edited 1 time(s). Last edit at 12/20/2013 04:31AM by nechaus.

Steam in the plastic can (but may not) generate bubbles. Those are not going to help anything at all....

To answer some of my original questions in case anyone else is interested:

Yes, pre-baking/drying the filament before printing helps

No, it isn't safe to bake your filament on the plastic spool it comes on.

Nylon 6 Unreinforced:
Drying Temp/Time, varies depending on the type of Nylon.
Your millage may vary!

Drying Temperature:
Range: 65°C to 130°C, (149ºF to 266ºF)
Average: 84°C, (183ºF ).

Dry time:
Range: 2 to 16 hours.
Average: 5.65 hours.


Printing parameters:
Substrate, and Enclosure temperatures should be below your Glass-transition temperature.

Glass-transition temp:
Range: 42°C to 142°C.
Average: 111°C, (232ºF ).
Wikipedia: 47°C.

Begin your testing around this temp:
Substrate temperature: 47°C, (117ºF ).
Enclosure temperature: 47°C, (117ºF ).

another thing i tried the other day was chopping a small piece of nylon, put it in mineral oil at like 150c, if it has lots of moisture you will hear it pop as the moisture leaves the piece.


iv been drying this trimmer line heaps lately, its summer in australia, been getting some aluminium foil, getting a small spool and puting it in my oven at 100c
every 2 hours or so, id let it cool, you can see the steam coming off it when you first pull it out, i dry it a couple of times.
iv got 2.7mm trimmer line, when its un dried its close to 2.9mm.

I can really tell the difference when its dried on how stiff the nylon is as well, almost feels like PLA when fully dry

Drying filament in a vacuum chamber:

Werner Berry

I think I need to do this with my nylon.

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Yvan

Singularity Machine

Great video, tks for pointing it out!

I have finished printing with 1kg of trimmer line, 3mm, dried It heaps, all printed at 250c-260c pushing the hotend to the limits.. still going strong now ..
anyway, I wasted lots of plastic but had some fun, I printed many things, extruder gears, vases, higher temp parts, parts, lots and lots of bushings..

No heated bed
used adhesive spray to hold the part down to prevent warping
10-15mm brim
20mm's print speeds
.5mm nozzle

found that .3 layer height worked the best.

the colour started off as a deep red, but once drying It for hours and hours in the oven that is a piece of crap and does not know what 80c means it losses its colour.

still prefer using pla until I get an e3d all metal badboy

Edited 1 time(s). Last edit at 01/06/2014 08:58AM by nechaus.

wow those look amazing. i had stopped printing nylon because it was giving me headaches, but now that ive got my carbon filtration setup on my rig ill give it a go again, the stuff is dirt cheap and the pieces that actually came out looked amazing.

I decided to give it a go as well, and just purchased a 3lbs spool of 2.7mm dia for less than 30$. I'm sure i could have found it cheaper than that if i spent more time searching, but still real cheap!
Also i noticed you can get these with reinforcements already in place, good for extra sturdy parts!

I intend to print bushings for cars eventually, so it's good to know the layer adhesion is very good and this stuff is real cheap.
Only drying will be an issue, but i'm certain i'll come up with a solution to that as well

at harbor freight they sell a dehydrator for 25 bucks, the chamber is round and would be perfect for drying coils of filament.

Hmmm - I wonder if I could get my food dehydrator to work for this.

Nylon is my next thing to attempt filament wise.

What is a good source and price in the US?

filtration on the printer sounds good, I need to get some dehydrators as well, one for food and one for filament..
this is for 3mm setup and it actually about 2.5mm-2.7mm
I was setting first layer to 300% layer width under advanced setting in slicer

This is the filament [www.amazon.com]


Maxpower 333605 Residential Grade Round .105-Inch Trimmer Line 690-Foot Length


List Price: $23.99
Price: $23.14 & FREE Shipping on orders over $35. Details

•.105-inch Diameter Trimmer Line
•690-Foot Length; Approx. 3 lb. spool of line
•46 refills
•Red color, round shaped line made from sturdy nylon components
•Made in the USA