ASA Drying Temperature: How to Properly Dry Filament for Best Prints

Understanding ASA and Moisture

ASA (Acrylic Styrene Acrylonitrile) is widely used in 3D printing for its durability and excellent resistance to UV light, moisture, and weather conditions. However, ASA is hygroscopic, meaning it absorbs moisture from the air over time, which negatively affects the printing process and final product quality.

When ASA absorbs moisture, water molecules interact with the polymer chains, breaking them apart. This leads to poor surface quality, reduced layer adhesion, stringing, bubbling, and weaker mechanical properties. Drying ASA before printing is critical to minimize defects and ensure reliable results.

Ideal ASA Drying Temperature and Process

The recommended drying temperature for ASA is 60-70 °C. This range removes moisture effectively without deforming the filament. Drying should typically last 4–6 hours, with up to 8 hours for heavily saturated spools.

Use a filament dryer with accurate controls if possible. A conventional oven can also work, but monitor closely to prevent overheating. An external thermometer is useful to verify temperature accuracy.

Consequences of Printing ASA Without Proper Drying

Printing wet ASA can lead to bubbling and popping sounds during extrusion as moisture turns to steam. Surface imperfections like roughness, pitting, or fuzzy textures appear, making parts unattractive. More importantly, poor layer adhesion reduces tensile and impact strength, and dimensional inaccuracies compromise part functionality.

Storing ASA Filament to Prevent Moisture Absorption

• Keep spools in airtight containers with desiccant packs.
• Use vacuum-sealed bags for added protection.
• Consider humidity-controlled dry boxes with hygrometers for long-term storage.

Printing ASA After Drying

Once dried, ASA prints reliably. Typical settings include:

• Extruder: 235–255 °C
• Bed: 80–100 °C
• Enclosure: Recommended to reduce warping
• Build surface: Glass, PEI, Kapton tape, or adhesive sprays
• Cooling: Off or low speed

Properly dried ASA ensures smooth extrusion, strong bonding, and accurate dimensions.

Comparison with Other Filaments and Drying Needs

Best Practices for Drying ASA Filament

• Preheat the drying device for stable control.
• Verify temperature with an external thermometer.
• Do not leave filament unattended in ovens.
• Seal dried filament immediately to prevent reabsorption.
• Weigh before and after drying if unsure about moisture content.

Advantages of ASA for Outdoor and Industrial Applications

ASA offers UV and weather resistance, making it excellent for outdoor parts like signage, garden tools, housings, and automotive components. It resists cracking, deformation, and chemical exposure, while also supporting post-processing such as acetone vapor smoothing for glossy finishes.

Industrial Adoption and Long-Term Performance

ASA is widely used in industries like automotive, outdoor equipment, and architecture. It maintains stability and strength even after years of service, reducing replacement needs and saving costs in demanding applications.