RE: Using heated bed to dry filament
doesn't remove it from the surrounding area or the filament.
Oh, I missed that part. Yes, it absolutely does remove it from the filament. Heating the filament to a high temperature increases the vapor pressure of water in the filament above ambient pressure, removing it from the filament into that air. You could remove MORE by increasing the vapor pressure gradient by reducing the ambient vapor pressure by having lower ambient humidity. Or you could remove more by increasing the vapor pressure gradient by increasing the filament temperature by having a higher ambient temperature.
RE: Using heated bed to dry filament
@alexw
That's a more thorough explanation. So there are 2 mechanisms that could be at work to remove the water vapor from the chamber: diffusion & convection (natural or fan-forced). You're relying mostly on diffusion & you've proven it works better without foil lining than with. That makes sense. But you need to wonder if filament is more hygroscopic than the cardboard walls of the chamber. If so, the water vapor will more readily absorb into it than leave the chamber. Or even if cardboard is more hygroscopic, it still impedes the removal of water vapor & it will take longer to dry the filament than if you have some convection going on.
Whatever you find to do with your hands, do with all your might!
RE: Using heated bed to dry filament
you've proven it works better without foil lining than with.
No, the opposite.
The fact that the ambient humidity peak is lower without foil does certainly imply that the cardboard allows more moisture transfer, which we agree is logically expected. But the data also suggest that the sponge actually finished drying sooner WITH the foil, DESPITE that the ambient humidity got higher.
In other words, the bottleneck to drying in this particular scenario isn't getting moisture out of the box (air exchange), it's getting moisture out of the moist thing (temperature).
RE: Using heated bed to dry filament
I thought we agreed that the liquid evaporation from the sponge wasn't a good analog for drying filament. Higher vapor pressure in the chamber air increases vapor absorption into the filament (or at least slows the drying process). It also increases vapor diffusion out of the chamber, but that takes time.
you've proven it works better without foil lining than with.
No, the opposite.
The fact that the ambient humidity peak is lower without foil does certainly imply that the cardboard allows more moisture transfer, which we agree is logically expected. But the data also suggest that the sponge actually finished drying sooner WITH the foil, DESPITE that the ambient humidity got higher.
In other words, the bottleneck to drying in this particular scenario isn't getting moisture out of the box (air exchange), it's getting moisture out of the moist thing (temperature).
Whatever you find to do with your hands, do with all your might!
RE: Using heated bed to dry filament
I wonder if its possible to use the heated bed to dry filament?
Although I don't like the idea of using cardboard, I found this.....
RE: Using heated bed to dry filament
Notice that some printers automatically shut down bed heating after some time, for example Prusa Mini+ does that, which makes it unusable.
Just get food dryer.
See my GitHub and printables.com for some 3d stuff that you may like.