Humidity, a problem in 3D printing. How can it be prevented?

Humidity is one of the sneaky culprits that can wreak havoc on 3D printing, particularly when it comes to filaments. These materials are highly susceptible to absorbing moisture from the surrounding environment. The science behind it is quite straightforward: water molecules latch onto the polymer molecules in the filament, forming resilient intermolecular bonds. While this might sound harmless, these bonds often lead to internal micro-fractures, diminishing the filament’s structural integrity. The challenges escalate when the filament reaches the HotEnd during the printing process. Any absorbed moisture tends to evaporate when exposed to high temperatures, creating voids within the filament itself. These voids—often invisible to the naked eye

—are weak points that pave the way for cracks even under minimal pressure. On top of that, the evaporation process can cause imperfections like a rough or whitish finish on the printed object‘s surface, undermining its overall quality and aesthetic appeal. Addressing humidity issues is therefore critical to achieving reliable and professional 3D printing results.

Some 3D printer users use conventional methods to remove moisture from the filament and store it, such as drying the material in a home closet and storing the filament in boxes that are not completely airtight. These measures, in addition to being dangerous, are not completely effective.

How do we prevent humidity in the case of 3D filaments?

The lifespan of a quality filament is 2-3 years from production, as long as it is in its original seal and vacuum. Once the bag is opened, the time it takes for it to lose its mechanical properties and color depends on the type of material and its storage. A PLA or ABS filament can maintain its properties for more than 1 year, but if it is not stored correctly it will last a tenth of that time. In delicate materials, such as Nylon and PVA, the total loss of properties can be caused in a few days, both due to drying and storage of the materials. Wanhao Box 2 has 4 filament feeding holes of 1.75mm – 3mm.

Wanhao Box 2 is the optimal solution for long life of 3D filaments. With this case you control the humidity, set the temperature, drying time and measure the filament left on the roll.

Conclusion

The text clearly identifies humidity as a major source of failure in 3D printing, specifically affecting filaments through water absorption. This absorption is critical because water molecules form strong intermolecular bonds with the polymer structure, leading to internal micro-breaks that significantly weaken the material.

The most damaging effect occurs during printing: when the filament is heated in the HotEnd, the absorbed humidity evaporates. This evaporation causes voids within the filament and, crucially, creates voids between the printed layers (often not visible to the naked eye). These internal flaws are critical stress points where cracks can easily initiate under minimal force, leading to mechanical failure of the final part. Furthermore, this process visibly degrades the object’s surface quality, resulting in a rough, whitish finish. Maintaining dry filament is therefore essential for achieving both strong, reliable parts and high aesthetic quality