How to dissolve PLA?

[CaseyScalf 1]

I have really be excited about the Olsson block. It has allowed much more creative control. I am swapping them out all the time.

However, that has led to them getting clogged.

How do we dissolve it best? I am talking single solution from Amazon* that everyone can use as a standard?

This stuff happens. We need a dialed fix. For instance, take JimC's words:

i cleaned my hot end the other day and am kicking myself for not taking a pic of this but i soaked it as usually in my paint stripper bucket. It loosened all the plastic in the nozzle and brass tube as usual but this time I didn't let it sit too long and i was able to actually pull the plastic out of the tube in one piece. it was kinda like a plastic straw lining the brass. i set this on the work bench and let it harden back up a bit then i took my Exacto knife and sliced the end off. in the cross section you could actually see the rainbow layers of each color i had printed with over the past 3 weeks or so. this was the first actual hard evidence i found that many plastics dont intermix welll and each time you switch you are left with a thin film that stays in there cooking and it gets harder and harder making the hot end tighter. http://3dprintboard.com/archive/index.php/t-3088.html

Anyways, as you can see it happens. Now how to deal with it?

I found this blog post from 2012 which explored quite a few solutions in nice scientific fashion, 2 out of the 10 worked. Both were hard to find. http://www.vinland.com/blog/?p=68

What is the current state of affairs regarding dissolving PLA from brass hot ends?

[IRobertI 521]

I'm afraid we're still at the nasty chemicals like chloroform stage when it comes to PLA and solvents.

Some people have had good success with burning it out and then rinsing in alcohol. I believe korneel made a tutorial on that a while back. I don't have the link handy right now but I'm sure someone else does.

You could also experiment with atomics with other materials like XT or Nylon, both will sometimes remove stuff that straight PLA wont.

[CaseyScalf 1]

Great to know! Thank you for the status report Robert.

I feel this would be a handy solution to have - no pun intended.

What is the major obstacle?

Is the chemistry really difficult or challenging? Or have just not enough experiments been done?

It seems like there are plenty of solutions for the ABS side of things - which I understand is a different composition - but it would be very handy to clean out these tips with multiple steps or serious rare/dangerous chemicals.

[CaseyScalf 1]

Any leads on this?

I can't imagine with all the makers engaging with PLA we haven't come up with a simple way to dissolve this?

I feel everyone has that hot swappable Olsson Block nozzle setup by now. Why can't we have a jar of fluid that we put them in to clean them out.

I have noticed that the printer performs so, so, so much better with a clean nozzle. Even switching one color of filament builds up deposits that accrue and accrue.

Best,

[tommyph1208 55]

Any leads on this?

I can't imagine with all the makers engaging with PLA we haven't come up with a simple way to dissolve this?

I feel everyone has that hot swappable Olsson Block nozzle setup by now. Why can't we have a jar of fluid that we put them in to clean them out.

I have noticed that the printer performs so, so, so much better with a clean nozzle. Even switching one color of filament builds up deposits that accrue and accrue.

Best,

 

You could buy some cleaning filament like the one from eSun mentioned in this old post, and run some through your hotend every time you switch filament...:

https://ultimaker.com/en/community/9405-quick-review-of-the-esun-cleaning-filament

I have some and push 10 cm. through the hotend from time to time... It is kind of like an abrasive that will scrape little filament leftovers along with it... so far it has worked out nicely for me.

Of course you can't use it once the damege is done and your hotend has clogged completely... think of it more as a "preventive step".

Edited July 15, 2016 by Guest

[tommyph1208 55]

Btw... I don't recognize the feeding errors mentioned in the post when I try mine (I have the |Robert| UM2 feeder on my Ultimaker Original with an E3Dv6 hotend)... I think he makes it sound harder than it is... I just load it in like regular filament, heat up the hotend and feed 10 cm.

Edited July 15, 2016 by Guest

[CaseyScalf 1]

Is there a consensus that the cleanliness and clean throughput of a nozzle degrades over time as a result of PLA (or other) filament build up?

If so, this must be a relevant pursuit.

It would be wonderful if there was a simple solution, or process, to apply to the nozzles to get them cleaned out.

Imagine a fresh nozzle each time...

[Baseline 30]

You could use IPS Weld On #3 found here on Amazon https://www.amazon.com/Acrylic-Plastic-Cement-Applicator-Bottle/dp/B0149IG548/ref=sr_1_1?ie=UTF8&qid=1470760033&sr=8-1&keywords=ips+weld+on+3

IPS Weld On #3 can be used to make a slurry just like using acetone on ABS and it is a far superior way to bond PLA compared to superglue.

[evenlu 0]

I had a clogged nozzle and recently tested different fluids for cleaning it. I found terrace cleaner being really effective removing stained PLA both from the inside and outside of the nozzle.

I used a small ultrasonic bath with the cleaner filled just above the nozzle. I tried both settings on the bath (35 and 60 kHz), but I am unsure whether it was the ultrasound that did the trick. Terrace cleaner contains all sorts of acids and the one I used had <5 % sodium hydroxide, <5% nitrilotriacetic acid (NTA), <5% amphoteric tenside and <5% sodium gluconate. My nozzle was full of residue and was more or less free of any after about half an hour in the bath.

[geert_2 558]

In my experience, when printing only in PLA, then atomic pulls do work reasonably well if done regularly, every week or so. Then, inside the nozzle, it burns into a dull brittle layer, but does not really build-up.

But PET seems to build-up more, especially in the corners of the nozzle, and is more difficult to remove. It becomes a sort of hard coating. And it takes a lot more atomic pulls to get that cleaned out.

Would be nice if we could just heat up the nozzle with its own heater to burn out the residu. Remove filament and bowden tube, heat-up nozzle, burn residu away, brush ashes off, blow dust off, and ready to go.

A bit similar to how exhaust filters in a diesel car engine are cleaned, just by increasing temp (in this case by injecting diesel fuel into the exaust, so it burns in the filter).

[Kakrofoon 0]

I just had a base layer roll up and melt over my whole hot end; I wound up having to use a knife get the element screw loose. I happened across this thread hoping to find a solvent that would work, and it looks like only break parts cleaner would even kind of work. I also read that PLA has a thermal degradation mechanism, and considering the hot end was a lost cause I pulled out a propane heater gun and tried heating it. The PLA basically wetted into the aluminum and brass and boiled off, and the residue appeared to be just pigment and cleaned up with alcohol. I did overheat the aluminum a bit (the surface got rough), but the nozzle and block still work OK. My setup is maybe 10 bucks, and made the nozzle look brand new - I've put another 20 hours on it since, with no issues.

[Wilhelm Lehmann 0]

Simple Solution to Dissolve PLA is THF (Tetrahydrofuran) whose preferred IUPAC name was changed in 2013 to oxolane. It is used in the Pool industry, as well as in 3D Printing, and vinyl printing (like Vehicle wrapping)

 

See https://en.wikipedia.org/wiki/Tetrahydrofuran