Vacuum Bags for Filament  

RE:

I use those, you can buy only bags or a bundle with an electric pump:
https://shop.eibos3d.com/products/eibos-3d-filament-pump?variant=44288617709747

Unlike the other bags you can find on Amazon, seals don't lose vacuum over time nore utilizations.

RE: Vacuum Bags for Filament

I tried the vacuum bag from 3Djake, but it leaked constantly.

In contrast, the eSun eVacuum Kit Pro 3 works perfectly. I’ve been using it for three months now and have opened and closed it about 20 times without any issues. I use it to store my Polymaker filament spools (which are made of cardboard).

RE: Vacuum Bags for Filament

Posted by: @scott-18

I use those, you can buy only bags or a bundle with an electric pump:
https://shop.eibos3d.com/products/eibos-3d-filament-pump?variant=44288617709747

Unlike the other bags you can find on Amazon, seals don't lose vacuum over time nore utilizations.

I also use the Eibos bags with their pump. (I got a huge amount from one of their kickstarters a couple years ago.) I really like that the pump screws onto the vacuum port so I can be doing other things while the bag is pumping down (instead of holding a pump to the bag). What I don't like is the vacuum port is in the middle of the bag so when I put the bagged spool back into the filament's box the side bulges out a bit. The Eibos bags are heavy gauge plastic, and hold their vacuum and protect from humidity (I put one of those paper color-changing humidity strips in each bag) much longer than double-bagged zip-lock gallon bags.

RE: Vacuum Bags for Filament

I use a la-va food vacuum machine and associated bags. 

RE: Vacuum Bags for Filament

Thanks!

Also, does anybody have any good advice on what filament dryer to buy? All of the ones out seems like there cheap, don't get to the right temperature, which one do you prefer and own?

RE: Vacuum Bags for Filament

Posted by: @giorgio1

Thanks!

Also, does anybody have any good advice on what filament dryer to buy? All of the ones out seems like there cheap, don't get to the right temperature, which one do you prefer and own?

 

I agree that all of them seem cheap and seemingly all are made in China. If Prusa made one, I would buy it in a heartbeat. (Well I would've, now I've already got one). 

I've got this one, the Creality Space Pi. I chose that one specifically because it has a built-in fan which I assume helps a lot in drying filament. I'm happy with my purchase, except for that the built-in fan makes an uncomfortable noise. Not such a big deal regardless, since you don't want to be in the same room as it's drying anyway (it gives off an unpleasant smell). 

I wouldn't worry too much about temperatures being exact. If the actual temperature is 58 instead of 60, it won't make a noticeable difference.

RE: Vacuum Bags for Filament

I think the Sunlu s2 dryer from AliExpress is pretty good for the price

RE: Vacuum Bags for Filament

I've got a Sunlu S4 which I really like and and an esun single spell unit which I think is the same as a Sunlu S1 with a different badge, it's ok but not as effective as the S4, it needs a pot of silica in it to work effectively which the S4 does not

RE: Vacuum Bags for Filament

Thanks for everyone’s recommendations!

i’m trying to decide to either get the Comgrow Filament dryer or the Sunlu S2

which is better?

RE: Vacuum Bags for Filament

I never understood why vacuum bags and pumps are considered helpful for keeping filament dry. Why is a well-sealed ziplock bag not good enough?

The small volume of air which remains inside the bag will contain a negligible amount of water; I can't see why absorbing some of that should have any significant impact on the filament. It's the constant supply of new (humid) air from the room which one needs to stop, and any sealed plastic bag should do that in my understanding. 

RE: Vacuum Bags for Filament

Ziplock bags are not air tight at all (air can migrate through plastic). Have you ever tried vacuum it with a straw (spool inside)? In few days it's not vacuum anymore.

For some filament highly hygroscopics I want a better air tight bags, but for all my pLA spools I use regular ziplock bags. 🙂

RE: Vacuum Bags for Filament

But how much air will migrate through a Ziplock bag if there is no driving force (pressure gradient due to a vacuum), but just diffusion (same air pressure inside and outside)?

Ok, it can't hurt to buy vacuum bags made out of thicker plastic. But I think there is no need at all to buy and use a pump and actually evacuate them. 

RE: Vacuum Bags for Filament

The ziplock bag will help in the short run, but if you have filaments you don't use for an extended time I'm afraid it won't do. I'll start with saying I'm new to 3d printing and never had to store filament for a long time, but due to my job I'm very familiar with vacuum sealers. A piece of meat in a ziplock bag will get freezer burn and ice buildup over some months whereas a properly vacuumed one will not. I'm aware that a wet piece of meat isn't the best analogy to dry filament but for the meat to dehydrate the humidity has to find a way out of the bag so if anything it shows that ziplock isn't humidity proof for longer time periods.

A vacuum sealer is a handy tool not only for filament, you can freeze leftovers or raw meat/fish and thaw/heat them again very quickly or do "sous vide" cooking so I wouldn't regard a purchase as a one trick filament pony, it can change the way you buy food and cook. Consumer grade bar vacuum sealers go for around 30-40€ so it's not a big investment.

RE: Vacuum Bags for Filament

It isn't air that migrates through, it is the moisture. Water molecules can slip through the zip-lock plastic. The magic terms are permeability and osmosis. Some plastics are less permeable than others, and the food vacuum bags are made from this type of material. 

That said, I've had spools of PLA go bad sitting in the factory sealed bag for a few months. Pretty sure it is the PLA composition at fault when you see snapped brittle filament pieces where they had strung the filament through the retaining holes. So whether or not bags help is, well, a maybe. I now keep PLA and PETG filament in large weather sealed tubs with plenty of desiccant (500 grams per tub). This keeps the tubs below 20% RH. It takes expensive specialized desiccant to keep humidity much lower. 

I keep my PC/ABS/ASA in vacuum bags that have valves on them - using a small battery pump to remove air - the bags go into the same larger tubs. Again, not sure this really helps that much, but it is the best I can do with what I have available.

RE: Vacuum Bags for Filament

Those plastic bags are useful for a limited period of time, but eventually they will leak. Some brands are better than others of course, The ones sold for the purpose of storing clothes in the minimum space possible are too big and unreliable for filament. In a few minutes, you see the bag expanding again as air infiltrates inside. 

After a few unsatisfactory essays with different bags I ended up purchasing a pack of dedicated vacuum containers manufactured by PrintDry. Very sturdy and reliable. Even with these don't expect that the filament will keep dry for months. Every now and then you must check if the desiccant inside the container starts changing color from light orange to greenish. When this happens you should  dry the filament in a food dehydrator or a dedicated drier. Desiccant serves only for keeping the air dry so that the filament doesn't takes more humidity, but it won't extract moisture from already wet filament, not a bit. You can do that only with heat.

RE: Vacuum Bags for Filament

Posted by: @artur5

Desiccant serves only for keeping the air dry so that the filament doesn't takes more humidity, but it won't extract moisture from already wet filament, not a bit. You can do that only with heat.

I don't believe that's true. Desiccant will dry filament, but slowly (several days). Let's say you have desiccant that's not saturated and place it in an airtight box, and lets say the humidity drops to 15%. Your filament spool has been in another environment with relative humidity 50%, and has been in that environment for a long time. If you place the filament spool in the air tight box with lower relative humidity, the filament will start to expel moisture into the relatively drier surrounding air, and the desiccant will absorb the moisture that's expelled into the air. In the end you'll reach a new relative humidity inside the box of like 20% of something, depending on how much desiccant you have in the airtight box. 

RE: Vacuum Bags for Filament

Anyone else think these cardboard spools are a bad idea? I'm in a humid environment and I'm buying Bambu filament because it is cheaper here, but also because they use plastic spools. I haven't seen anyone do tests on the cardboard, but I think it would absorb more moisture than the filament and then your efforts would need to dry both the spool and the filament.

RE: Vacuum Bags for Filament

Posted by: @crab

Anyone else think these cardboard spools are a bad idea? I'm in a humid environment and I'm buying Bambu filament because it is cheaper here, but also because they use plastic spools. I haven't seen anyone do tests on the cardboard, but I think it would absorb more moisture than the filament and then your efforts would need to dry both the spool and the filament.

I've also had the same thoughts. I think it's a valid concern, but I don't think it's a problem in terms of drying in a drier. The drier would just dry the cardboard as well as the filament. I think it's a bigger issue if the cardboard gets wet with moisture (much more quickly than the filament), you put the spool into a sealed plastic bag, and the moisture from the cardboard disappates into the filament. 

RE: Vacuum Bags for Filament

What if:

Some cardboard spools are *MORE* hygroscopic than PLA?

This means your PLA spools absorb significant moisture just being out on a holder printing (in summer when more humid). Then when you store in sealed containers, the moisture in cardboard overwhelms the desicant.

Would be a good study for some YouTuber to take on.

I’ve moved all my PLA/PETG to the reusable Bambu filament because the refills are $17 where Prusament, here, is $52. Not sure how Prusa sells its filament. I’ve found Bambu prints fine. In fact, I’ve never used my Prusa meters I’ve accumulated on Printables because the shipping/duty/import fees are more per spool than I can buy the refills.