Why dry filament matters
Filament absorbs moisture from the air. That moisture turns to steam in the hot nozzle and causes bubbles, stringing, a rough surface and weaker prints. Nylon, TPU and PETG are especially sensitive. Damp filament costs you failed prints, and those cost money (see failed prints and waste).
How to recognize damp filament
- crackling or hissing while printing;
- bubbles or a rough, dull surface;
- lots of stringing between parts;
- prints that are weaker than expected.
Drying guidelines
| Material | Temperature | Time |
|---|---|---|
| PLA | 45-55 °C | 4-6 hours |
| PETG | 60-65 °C | 4-6 hours |
| TPU | 45-55 °C | 4-6 hours |
| ABS / ASA | 65-80 °C | 4-6 hours |
| Nylon | 70-80 °C | 8-12 hours |
These are guidelines. Always follow the filament manufacturer's recommendation and your dryer's maximum temperature.
What does it cost?
Electricity for drying is small: a 100 W dryer (an estimate) running 6 hours is 0.6 kWh, about €0.18 each time at €0.30 per kWh. A failed 100 gram print already costs about €4.59. If drying prevents one failed print in 25 runs, the electricity has already paid for itself.
How to store filament dry
Store spools in a sealable box with desiccant (silica gel), especially if you will not use them for weeks. When printing sensitive materials, keep the spool in a dry box or dryer while it prints.
Frequently asked questions
Why does filament need to be dry?
Moisture in filament turns to steam in the hot nozzle and causes bubbles, stringing, a rough surface and weaker prints.
Which materials absorb the most moisture?
Nylon and TPU absorb a lot of moisture, and PETG too. PLA is less sensitive, but can also get damp after a long time in open air.
How do I recognize damp filament?
Crackling or hissing sounds while printing, bubbles, stringing and a rough or dull surface are signs.
What does drying filament cost in electricity?
With a 100 W dryer (an estimate) and 6 hours that is 0.6 kWh, about €0.18 each time.