Have you ever loaded a fresh spool of filament into your printer only to be greeted by stringing, popping sounds, rough surfaces, or weak layer adhesion? Before you start changing slicer settings or recalibrating your printer, the problem may actually be moisture.
Many 3D printing materials absorb moisture from the air over time. While some filaments are more resistant than others, nearly every maker will eventually encounter moisture-related printing issues. At RAPID + TCT, we stopped by the Sunlu booth to take a look at several of the company’s latest solutions designed to help makers keep their filament dry and ready to print.
Why Filament Moisture Matters
Filament that absorbs moisture can create a variety of print quality issues, including:
- Stringing and oozing
- Popping or crackling during printing
- Rough surface finishes
- Poor layer adhesion
- Reduced mechanical strength
- Inconsistent extrusion
Materials such as nylon, TPU, PETG, and many engineering-grade filaments are especially susceptible to moisture absorption, making proper storage and drying an important part of the printing process.
AMS Heater: Dry While You Print
One of the newest products on display was the Sunlu AMS Heater.
Designed to work with the popular Bambu Lab AMS ecosystem, the AMS Heater replaces the existing AMS lid and adds active drying capabilities while printing. This allows users to continue feeding filament through the AMS while simultaneously removing moisture from the material.
For makers running multi-color prints or keeping multiple spools loaded at all times, this can help maintain filament quality without needing to remove and dry spools separately.
E2 Filament Dryer: Built for Engineering Materials
For users working with moisture-sensitive engineering materials, Sunlu showcased its E2 Filament Dryer.
What makes the E2 stand out is its ability to reach temperatures up to 110°C. While most users won’t need temperatures that high for everyday materials, the elevated temperature capability allows faster drying of demanding filaments such as nylon.
According to Sunlu, nylon that might require 10 hours in a conventional 70°C dryer can potentially be dried in roughly three hours at higher temperatures.
The E2 also includes annealing capabilities, giving advanced users additional options for improving material performance after printing.
S4 Dryer: Still a Fan Favorite
While not a new release, Sunlu’s S4 Dryer continues to be one of the company’s most popular products.
Designed to accommodate multiple spools, the S4 has become a staple for makers who frequently print with moisture-sensitive materials and need a reliable way to keep several filaments ready for use.
Sometimes the most exciting product isn’t the newest one—it’s the one that consistently performs year after year.
SP2 Dryer: A Different Approach to Storage
Another interesting product showcased at the booth was the SP2 Dryer.
The SP2 uses a modular, stackable design. A single heating base can be used to dry individual storage chambers, which can then be sealed for long-term storage.
Once dried, the chambers can help keep filament protected from moisture for extended periods, reducing the need to repeatedly dry the same spool before every print.
For makers with large filament collections, this approach could simplify storage while helping preserve print quality.
Dehumidification Instead of Heat
Perhaps the most unique system on display was a new dehumidification cabinet developed through a partnership with Inslogic.
Unlike traditional filament dryers that rely primarily on heat, this system focuses on removing moisture from the surrounding air using a specialized desiccant-based dehumidification process.
The cabinet can hold up to 10 spools and continuously circulates air through the enclosure. Moisture is captured by the desiccant material, which is then regenerated using an integrated PTC heating system.
An automatic venting system helps remove moisture from the cabinet without requiring user intervention.
The result is a solution designed to maintain low humidity levels inside the cabinet while consuming less energy than continuously heating multiple spools.
Drying vs. Dehumidification
One of the interesting takeaways from Sunlu’s lineup is that there is no longer a single approach to moisture control.
Traditional dryers use heat to actively remove moisture from filament.
Dehumidification systems focus on controlling the environment around the filament, preventing moisture absorption in the first place.
For many makers, the ideal setup may involve both methods—using active drying to restore wet filament and controlled storage to keep it dry afterward.
Filament drying isn’t just about preventing failed prints. It’s about protecting your materials, improving print consistency, and ensuring your filament is ready when inspiration strikes.
Whether you’re looking for a simple dryer, a high-temperature solution for engineering materials, a long-term storage system, or a dedicated dehumidification cabinet, today’s makers have more options than ever for controlling moisture.
And while dry filament won’t guarantee a perfect print, wet filament can certainly ruin one.
Have you tried a filament dryer or dehumidification system? Let us know what has worked best in your workshop.