wet to dry filament

[B Stott]

I think I've some wet filament.

The printed part is crystalline looking, odd textured and brittle. No, I don't have a stash of desiccant packets. To think for all those years I've been wanting to save those little satchels. If I had - I'd go, with a smile, to my box and be set with cozy dry filament. Oh well....

Has anyone dried their ABS plastic in the oven? I'm turning my oven to 200F (~93C) for ??? an hour?

[Whosawhatsis]

Dry (uncooked) rice makes a decent desiccant. As for the oven idea, I
would consider that a last resort. Ovens don't a great job of
maintaining steady and consistent temperature, especially at the
bottom of their temperature range. You're going to have temperature
fluctuations and hot spots, either of which might get hot enough to
deform the filament enough to prevent it from feeding properly or at a
predictable rate.

Now, if you had a food dehydrator you could put it in, that might be
worth trying.

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[B Stott]

Yeah, I changed my mind about the 200F temperature. I've lowered it to 170F (~77C). That is safe for wild fluctuations. I've a baking stone to even out hot spots so the tender target won't be on bare metal.

Foodstuffs - rice - seem kinda expensive. How much rice do you use?

[Whosawhatsis]

Never tried it on filament, but in theory, the more contact area, the better.

Actually, I don't think the oven will have much affect on the moisture
content at any temperature. If the filament is dripping wet, you may
be able to get some water to evaporate, but then it just turns to
steam in the air until it re-condenses (probably on the filament).
Even a convection oven will just recirculate the same damp air.

What you need to do is spread the filament out and blow warm, dry air
over it, as is done in a food dehydrator.

[B Stott]

Oh, forgot to mention - I'd read that plastic processors put their pellets into the oven to dry before they process. Thought is - good enough for the 'big' maker - good enough for the 'little' maker.

[Whosawhatsis]

Go ahead and try it if you want, but I think they oven they're talking
about is probably better-equipped for drying things out than the one
you're likely to have.

[B Stott]

hmm. You are right.

But, neither do we know enough about the replication processes that maybe we shouldn't be hackin with this stuff. ;-)

[B Stott]

Say Whosa...

Check out my pictures - two parts - same plastic. One from humidity, one from oven.

Did you ever make beef jerky? Did you ever dry apples? W/O a dehydrator? We did - we used the oven. When I bake bread (yepir - do that too... :-)) and I want a crispy crust I have to put in a pan of water, spray the oven and block the vent. Most ovens have vents to let out the moisture. Otherwise, you'd not be able to see in when you bake.... 

Anyway, guess what? We have another method to use. I printed with some natural ABS this morning and the print - a bearing - was Terrible. The surface was crystalized and mottled and the filament did not behave right. The raft and part were very brittle. Well, I took that very same plastic and put it in the oven at 170F for 50 minutes - about. And then took it from the oven to the bot. Inserted it - ran a little through and then printed the absolute most handsome part. All the lines were perfect - except for the top when the hot end brushing fine details lifted the part from the belt. Anyway up to that point every layer was a work of art. Every layer glossy. All threads perfectly in line. It looks wonderful! This was the same plastic that gave me a cruddy looking part this morning.The plastic part is glossy and very firm like ABS should be.

I'm baking the others and then putting them into bags with - as you told me to - rice.

Thanks for the banter,

Brian.

[B Stott]

Dry filament - Amazing stuff to print with. I dried mine in the oven at 170F for about an hour. Then printed and I got the best smoothest prints I've ever had. This is with two different colors so far that were causing me some print problems.

[M.Rule]

I just tried this at 150 and the entire spool melted and stuck to itself.

[M.Rule]

*150F

[M.Rule]

best guess is that the plastic absorbed heat/infrared directly from the heating element and reached a temperature higher than the rest of the oven, placing on a sheet of cardboard made everything go much more smoothly.

[Brian Stott]

Uh, 150 degrees Fehrenheit not Celcius. Right? Mine cooks for and hour at 170 degrees F. No sticky. No tacky. Just real warm and dry.

And I don't bake anything but the filament.

---

From: M.Rule <mrul...@gmail.com>
Sent: Saturday, June 11, 2011 11:50 AM
To: make...@googlegroups.com
Subject: Re: [MakerBot] wet to dry filament

I just tried this at 150 and the entire spool melted and stuck to itself.

On Sat, May 21, 2011 at 6:45 PM, B Stott <sto...@gmail.com> wrote:

Dry filament - Amazing stuff to print with. I dried mine in the oven at 170F for about an hour. Then printed and I got the best smoothest prints I've ever had. This is with two different colors so far that were causing me some print problems.

On Fri, May 20, 2011 at 9:30 PM, B Stott <sto...@gmail.com> wrote:

Say Whosa...

Check out my pictures - two parts - same plastic. One from humidity, one from oven.

Did you ever make beef jerky? Did you ever dry apples? W/O a dehydrator? We did - we used the oven. When I bake bread (yepir - do that too... :-)) and I want a crispy crust I have to put in a pan of water, spray the oven and block the vent. Most ovens have vents to let out the moisture. Otherwise, you'd not be able to see in when you bake.... 

Anyway, guess what? We have another method to use. I printed with some natural ABS this morning and the print - a bearing - was Terrible. The surface was crystalized and mottled and the filament did not behave right. The raft and part were very brittle. Well, I took that very same plastic and put it in the oven at 170F for 50 minutes - about. And then took it from the oven to the bot. Inserted it - ran a little through and then printed the absolute most handsome part. All the lines were perfect - except for the top when the hot end brushing fin

[The entire original message is not included]

[Brian Stott]

Double ack. Sorry. When I mentioned I should have noted I preheated oven for about 40 min or so. This stablized the temp and I did set plastic on a paper on a pizza stone. I always keep the stone in the oven.

---

From: M.Rule <mrul...@gmail.com>
Sent: Saturday, June 11, 2011 5:21 PM

To: make...@googlegroups.com
Subject: Re: [MakerBot] wet to dry filament

best guess is that the plastic absorbed heat/infrared directly from the heating element and reached a temperature higher than the rest of the oven, placing on a sheet of cardboard made everything go much more smoothly.

On Sat, Jun 11, 2011 at 11:50 AM, M.Rule <mrul...@gmail.com> wrote:

*150F

On Sat, Jun 11, 2011 at 11:50 AM, M.Rule <mrul...@gmail.com> wrote:

I just tried this at 150 and the entire spool melted and stuck to itself.

On Sat, May 21, 2011 at 6:45 PM, B Stott <sto...@gmail.com> wrote:

Dry filament - Amazing stuff to print with. I dried mine in the oven at 170F for about an hour. Then printed and I got the best smoothest prints I've ever had. This is with two different colors so far that were causing me some print problems.

On Fri, May 20, 2011 at 9:30 PM, B Stott <sto...@gmail.com> wrote:

Say Whosa...

Check out my pictures - two parts - same plastic. One from humidity, one from oven.

Did you ever make beef jerky?

[M.Rule]

Yep, I should have remembered that this stuff starts to melt at
230f(110c). Thats not far from 170, easy to reach if the oven
overshoots, or the plastic warms faster than the rest of the oven.

I left it in at a bit cooler ( 100f? ) for many hours. I didn't
conduct a controlled enough experiment to see if this dried the
filament. Prints are no longer bubbly, but I also switched the
printing temperature from 235 to 225 at the same time.

[B Stott]

I'd hoped you'd have been a good proof. If you left your plastic in a good warm dry environment for hours - you surely did dry it. Too bad you changed two variables in your testing. Oh well, I can not usually change only one item either.

[B Stott]

Well another confirmation of the drying process for me.

I'd been trying to print charlespax's nozzle from http://www.thingiverse.com/thing:9006  a derivative of the cool:  http://www.thingiverse.com/thing:7572.

Six prints with various SF changes and not any better. The extruded plastic. when nozzle was narrowing, was bubbly and expanding. But, after the plastic dried in the oven for an hour at 77C (170F) the nozzle print actually looks - well - more nozzley. I still did not get the right result but very much better. Now, I will be able to see the SF changes rather than the foaming hot wet plastic.

[M.Rule]

I've been having a problem where filament, once dried, becomes wet
again in a matter of hours. It seems impractical to just store
filament in the oven and cut little pieces off as I use them, but
thats the only solution I can think of.

[B Stott]

Ok. I leave it in the oven for the hour. I may even let oven cool since I can be lazy. It gets very dry. I've not had it go soggy quick. The plastic I dried today was out in the bot for the entire week till it just got too unwieldy last night. So, I dried it today. I also just took out another plastic out of my bag of rice and it printed fine while I waited for the other to oven dry.

I think it may have been whosawhatsis or another makerboter who told me about rice. So, drop your dry into a trash bag with a hand full of rice and a quick twist and fold over the top. It stays dry. If it is on a spool? Fit it in? That's the plastic that we aren't using.

[cakeller98]

OK I haven't tried it, but based on this thread....

Rice is CHEAP! get a 20lb bag of rice, a deep roasting pan, place a TEST PIECE of plasting (not a $75 spool) into the rice, and use the same preheating method.

another test method might be simply to use the rice/dessicant on a rack above and below the filament

top rack place a 1" deep baking sheet filled with 3/4" deep rice

bottom rack use another 1" deep baking sheet filled with 3/4" rice and place a piece of paper on top of that, or cheese-cloth.

then place the plastic on top of the cheese-cloth.

this should block any IR from the elements, if they should come on.

as for the filament getting wet... yup, the injection molders often dry the plastic before use, and, I think, injection molding machines can have a dryer built into the hopper set up... but maybe,yeah just store the plastic with a bunch of the rice.

alternatively... you could try "Damp Rid".  Sold at Bed Bath and Beyond. it's sold in milk carton sized containers, and can be re-dried once it gets saturated, in an oven.

another alternative is to use plaster of paris... although it'd be messier, unless it was pre-cast into a slab/brick/?ice cube shapes?...  probably not as dessicating as the powdererd plaster of paris, but in Ceramics, we had a table made of plaster of paris we used to wedge the WET WET WET clay to suck out the extra moisture, kneading it on the surface.

anyway - interesting thtread, just wanted to share some thoughts of my own.

--- :)