Many 3D printing thermoplastics are hygroscopic, meaning they absorb moisture from the air over time. When this occurs, the filament may appear normal, but the absorbed water can cause problems during printing.
Once the wet filament enters the hotend, the moisture rapidly turns into steam. This disrupts smooth extrusion and leads to unstable flow, causing issues such as bubbling, poor layer adhesion, rough surfaces, stringing, and inconsistent extrusion. These defects can also reduce dimensional accuracy and overall part strength.
Recognizing wet filament early can help avoid failed prints and wasted material. Common signs include:
Different materials absorb moisture at different rates. The table below combines moisture sensitivity with recommended drying settings.
|
Material |
Moisture Sensitivity |
Drying Temperature (°C) |
Drying Time (Hours) |
|---|---|---|---|
|
PLA |
Low |
50 |
7 |
|
PETG |
High |
60 |
5 |
|
ABS |
Medium |
75 |
7 |
|
ASA |
Medium |
75 |
7 |
|
PC |
Medium |
75 |
7 |
|
NYLON |
High |
95 |
7 |
|
TPU |
High |
70 |
7 |