I love in Colorado, which is a pretty dry state, so while I had heard of “wet filament”, I never considered it to be a problem that I would have to worry about. I had seen people creating dry storage bins for their filament, but figured that must just be for people in humid climates.
When I first bought my 3D printer a few years ago, I did what most people probably do - I bought a 10 pack of different filament colors. Everything printed great for a while, but eventually, my prints just started to kind of suck. I made a few upgrades to my printer, but still couldn’t pinpoint what was going on. What was frustrating, is that some times my prints would be great - but other times I couldn’t even print the most simple prints without problems.
I eventually noticed that my great prints were from newer filament that I had recently purchased, but my bad prints were coming from spools I’ve had sitting out for a while. So I purchased a $40 filament dryer on Amazon and it instantly fixed all the problems I’d been having.
I feel dumb, because I had gone through three different extruders, new hot ends, new nozzles, tubing, and spent tons of time cleaning and tightening stuff on my printer. I had left my printer untouched for months because it was just so frustrating. Something as simple as old filament left out never occurred to me until much later.
TLDR; If your prints have started to suck after a while, you might want to try drying your filament.
So I’ve toyed with buying a dryer, but I never really understood a good workflow. Do you dry a spool right before you start printing with it?
What about storing spools? Is it sensible to leave them in “regular” storage before going into the dryer? Or should I be looking at having multiple dryers to keep more spools from getting wet. And at that point should I just be looking to make a more practical storage solution for many spools?
Most dryers now allow you to print directly from the dryer. I keep my spools like most in cereal boxes with a 100g dessicant sack. For pla I just throw it in dryer, set a timer on it, while I’m prepping my bed and print. Works well. For PETG or tpu I like to try to let it dry in the box for a couple hours before getting started. If you are not carefully keeping filament dry and switch to a sealed dessicant system, I would recommend putting the filament in a drying box for 8h prior to then putting it in your storage container. I tried vacuum bags for awhile and the cereal box thing is way less of a pain.
I store in home Depot containers with desiccant in the bottom. And have another modified to print from. (Printed spool holder with bearings, reverse Bowden through container side)
It really didn’t change my workflow, just where to get the spools to load, and where to load them.
Print quality improved greatly.
I still don’t understand how those cheap filament dryers work: they fully enclose the spool and heat up the air for a few hours. But where does the moist air go? It’s still trapped in there with the filament. It makes no sense!
I always leave the filament dryer a bit open so the warm air can escape, taking the moisture to a better place (far away from the filament)
Humidity is relative, not absolute. Air’s carrying capacity for water increases as temperature goes up, even if the total amount of water in the air is the same.
Air with 50%RH at 70F (eg, it has 50% of its max water content) only has about 10%RH at 120F. So if you get the filament hot, it gets dry. This can be improved with outside air circulation i guess, but it’s not necessary and usually causes extra energy use due to heating the makeup air.
That I am aware of. But without any circulation the hot air will simply cool down and condensate once I turn off the dryer, wouldn’t it? Leaving either highly saturated air or even some water droplets, ready to be absorbed by the filament again
This is true. If you left it in the same environment it would eventually return to equilibrium and the net result would be the same. the key is that the plastic has a limited take up rate of atmospheric moisture. so if you dry it for a few hours, the water migrates out slowly, but then takes quite some time to migrate back in.
generally people either print from a dryer box or dry filaments immediately before printing.
You’re supposed to put some type of desiccant like silica gel beads that will pull that moisture out of the air.
Leaving the box open will just let humid air in. You can’t let air out without also letting air in unless you have some sort of vacuum pump.
Now that you mention it, I have no clue! There’s no exhaust fan on mine. It definitely works though, so I assume the people that made it are smarter than me.