When does filament need to be dried?
Many plastics have strong hygroscopic properties, which means that they absorb moisture from their environment.
There are the following signs of moisture in the filament:
- Bursting or cracking noises during extrusion
- Uneven extrusion lines and lump formation
- Stringing or warping
- Low layer adhesion
- Reduced print bed adhesion
- Uneven surfaces
Which filaments should definitely be dried?
PA (nylon), PC, PETG, PCTG, TPU and filaments with carbon fiber should always be dried before printing. Especially with Exturdr TPU (FLEX Semisoft, FLEX Medium, FLEX Hard and FLEX Hard CF) it is recommended to dry the filament before printing. Other materials can be dried if necessary if the above-mentioned signs occur.
What are the options for drying filament?
To remove excess moisture, the filament must be placed in a suitable drying device for a certain period of time.
- Drying box
Various drying boxes offered by different manufacturers (e.g. SUNLU or eSUN) are specially designed for drying filament. The drying boxes work with heat, with newer devices also using airflow. The temperature in particular can be set precisely with these devices, which prevents the plastic from melting or forming lumps compared to an oven. Drying boxes are generally the safest option for drying filament.
- Oven
One method of drying filament is to dry it in an oven with a hot air function. It is essential to wait until the oven has reached the correct temperature. The preheating temperature of certain ovens can be very high, which can lead to the filament or spool melting. It should also be noted that polymers (e.g. ABS) can give off harmful vapors that do not belong in an appliance used for food preparation.
- Dehydrator
The filament can also be dried in a dehydrator. The same rules apply as for ovens. Such machines usually only have low temperatures, so the drying temperature of the material should be checked first.
What is the right drying time and the right drying temperature for filament?
The most important drying parameters are temperature and drying time. It is advisable to follow the specifications of material manufacturers.
Our extruded filaments can generally be dried at temperatures of 50° to 60° degrees (see table below). The drying time varies depending on the material. However, as polymers are poor heat conductors, it takes several hours for the heat to penetrate into the center of the filament.
Many plastics have strong hygroscopic properties, which means that they easily absorb moisture from the environment.
Exact details can be found in our Material Quick Guide.
Storing filament in a dry place is also crucial for optimum printing results. Find out more about the correct storage of filament in our blog post.