Nylon filament drying options
Since it's been brought up recently I felt like adding this post to document my experience with filament dryers and nylon.
Filament used: nylon weed eater line: BASF B33 ultramid, blend of PA-6 with additives.
Image 1: Nesco FD-75PR Max recorded temperature :75 c Max spec temperature: 71 c Time to dry nylon @70 c: 20-40 hours Notes: can fit 2, 1 kg spools some loose filament and a bunch of dessicant (does require cutting out all the trays). With 600W of heating power this will absolutely heat the shit out of whatever room you slap it in. Good for doubling as a space heater in the winter time. Not sure if it's a good idea to leave unattended but if you've got a USB camera and remote outlet you can keep an eye on it and shut it off remotely. For my fellow comrades with sky high electric rates this gives you the ability to turn it off during peak hours with at most 3 finger taps from you smart phone. As long as it's plugged with the knob set to your desired temp it will run
Image 2: Nesco FD-41B Max recorded temperature : 90 c Max spec temperature: 79 c Time to dry nylon @90 c: ~15 hours Notes: can fit 1, 1 kg spool, dessicant maybe some loose coiled filament. Still heats up the room but not as much. Drys nylon faster than the FD-75. Turning it on is more complicated as it requires pushing a button and turning your knobs to set drying temp and time. It will turn off automatically but setting up a remote outlet will only let you turn it off remotely. To start it again it needs user input.
Image 3: sovol 3D dryer box Max recorded temperature : didn't check Max spec temperature: 50c Time to dry nylon @50 c: forever Notes: The sun will run out of hydrogen before you dry nylon at 50c with this. I didn't even attempt to dry nylon at this temp and neither should you unless you hate yourself. This however does appear to keep dryed nylon filament from picking up moisture while printing though printing from a hotter dryer may be the better solution. If your on a budget or constrained by space, getting the hotter dryer will be more useful for you.
Moisture exposed filament was tested by cutting off a piece and melting with hot air at 262 c. If the filament is wet bubbles will form as it becomes molten. Once sufficiently dry little or no bubbles will form in the molten material. It's easy to see with translucent filaments.
I have previously commented that 70-75c is ok for drying nylon. While it is technically possible I will no longer recommend this as it just takes longer. If you can get a food dehydrator that can hit 90c, do it.