Just think about how much water those cardboard spools can suck up.
If I get concerned about filament moisture, I can put it in a vacuum tank I have. I used to use it to pull the air out of resin. The vacuum pump is for automotive A/C systems. Depending on the room temperature and elevation, water will “boil off” and be removed at a very low temperature. The chart below shows the boiling point of water at the indicated inches of mercury (vacuum). It only takes about 5 minutes. You can put a bottle cap with a couple drops of water inside as a gauge. Sorry, but I only have it in American values.
My general routine with a new spool is as follows.
I respool to a Bambu blank
Heat in dehydrator for a few hours to release tension and to prepare for next step
Overnight in a vacuum pot with stray desiccant bags
Seal in food vacuum bags with desiccant wedge
I will skip the vac pot if I need the spool immediately but generally put it back into the system from the beginning afterwards. I weigh before/after and find average 20g loss before I bag them.
It’s a process and it gives me a reasonable stable output with no brittleness or other moisture related problems. My environment is exposed to high humidity at times (evaporative AC).
Running spools inside the ams keeps them fairly stable and I rarely put them back into the heater/vac cycle. This is PLA/PETG/ABS/TPU (some CF’s of those).
I heat the plastic until it stops losing weight then store using a vacuum sealer you use for food along with a pack of color changing desiccant. I cut the bag extra long so I can open and close it several times.
I haven’t tested the temperature to see how consistent it has been. Might have to go find my temp probe to see how accurate it is. The built in hygrometer is far from accurate; I mostly use it to help gauge whether or not water is being removed from the filament or if I need to prop the lid.
Any idea if a vacuum is better at removing moisture from filament over a filament dryer? I’ve been wanting a vacuum chamber for a while, might need to invest in one sooner rather than later.
Back to the original question if I may. I stand my plastic storage box on it’s side and have put crossbars in it to make “shelves” for my rolls. I still put them in plastic vacuum bags and have a desiccant bag in it as well. I’m still not sure if pulling a vacuum on your filament is a good idea, as the moisture is basically turned into low temperature steam, and the increase in volume could cause voids and fractures.
I’ve been using one for a while now and prefer it to just using my dehydrator, makes no noise once it’s sitting and no extra heat in my room. I do preheat the spools for the extra kickstart (plus it de-stresses my respooling), I can’t say it’s better than heated air blowing over filament or not in my experience. Bonus points my wife utilises the pot for her resins so didn’t question the purchase
Better and faster. I can’t Imagine waiting days to get filament only having to wait days while it cooks. I’m typically printing the same day. Vacuum degassing is quick and thorough. However, you need a pretty good vacuum pump. It should pull 29.5 - 29.8inHg. A vacuum cleaner or the like is not good enough. And only lab equipment will usually get above 29.8inHg.
If it’s long-term storage, then seam-sealed thick mylar bags are going to beat most alternatives. That’s what freeze dried emergency rations that are meant to last 30 years are stored in, and it’s because they’re effective at keeping out moisture.
I mostly store my spools in vacuum bags in the original boxes on a bookcase. The Bambu boxes include a label that has a coloured spot so it’s easy enough to see what’s inside. I intend printing off similar labels for my non Bambu stock.
Perhaps, but the entire comparison is flawed. I couldn’t find any mention other than “vacuum” that he obtained enough except “boil water at room temperature”. The sad part is that’s not enough. If he was as scientific as he tried to display, he would be indicating vacuum in Microns and insured he reached at least a 1000 micron vacuum.
Otherwise, his vacuum tests are totally inaccurate and incomplete.
You’ll begin to notice problems with the spools you have dried in it, once you get about 2/3 into the spool.
I have ruined at least 4 PETG spools with it. And I usually use the lowest heat setting.
It’s the design of having the heating element in center of the spool that is an issue. It traps the heat there and causes it to be much hotter then the outside of the spool.
Do the people who develop this type of product ever actually use them? Or do they just not care? There seems to be widespread ignorance/incompetence, whether it’s willful or otherwise.
The Eibos dryer continues to get accolades from so many people. I really took a close look at it but I could not cross that chasm of buying a device that I could build on my own. I built two bed heated dryers that work perfectly well albeit they tie up my printer. Here’s a photo.
Device on the left is just a box with an active fan. After ruining a spool of PETG like you did, I reverted to a printed design which I modified on the right made from Bambu Lab white PETG. The active fan creates moving air which eliminates hotspots. The stand in the middle is the key, it keeps the spool off the bed and the fan circulates the air underneath the spool. It works perfectly but as I said, it takes up the bed while in use.
I just ordered the Creality Space PI. If I am going to buy something, I want it to be better engineered than I can and I want all the indicators that a Science Geek like me needs in order to validate that my results aren’t random. The Creality arrives Friday and I have two more weeks with the Sunlu S2 before the 30 day Amazon window closes. One of them is going back. I’ll be doing a bakeoff during the next week.
I find it quite perplexing myself. I figure most of those people haven’t ruined multiple spools yet to figure out that the dryer is the issue. It took me some time to come to that conclusion. My first thought was badly manufactured filament. But after the same thing (2/3 in) happening to other spools and how hot they felt removing them from the dryer, it became quite apparent.
Even turning the cheesy potentiometer to the lowest setting, still ruined another spool of PETG.
I complained about the Eibos design in another thread on this forum and had at least one other person tell me they’ve had the same bad experience.
The problem is even highlighted in the BBL wiki on drying filaments:
you should try to keep the filament away from the heat-generating area to ensure that the temperature is more even and correct. This will allow the filaments to be dried evenly without causing deformation or damage to the reusable spools and filaments due to localized overheating.
Admittedly, this is at odds with what people naturally want, though, which is a compact filament dryer.
Speaking of the BBL Wiki, it specifically recommends the use of a “blast oven.” So does vision miner’s website, by the way.
Just what the heck is a “blast oven”? Is it anything different from a convection oven? If it is different, in what way is it different?
I can also vouch for the home depot Ezy-storage containers. I use these exclusively with two reusable desiccate packs and a hygrometer maintaining around 10% RH.
