ASA Filament: The Outdoor Specialist for 3D Printing
ASA (Acrylonitrile-Styrene-Acrylate) is the weather-resistant counterpart to ABS – developed for outdoor applications. It combines the strength of ABS with excellent UV resistance and weather resistance. ASA is the material of choice for garden furniture, automotive parts and all applications exposed to sun, rain and temperature fluctuations. In this guide, you'll learn everything about ASA properties, print settings and when ASA is the right choice.
What is ASA?
ASA is a thermoplastic terpolymer chemically similar to ABS, but containing an acrylate rubber instead of butadiene. This modification makes ASA UV-stable and weather-resistant, while largely retaining its mechanical properties.
ASA is commonly used in the automotive industry (side mirrors, spoilers, radiator grilles) and has been proven for decades in outdoor applications.
ASA is characterized by the following properties:
- Excellent UV resistance (does not fade)
- Weather-resistant (rain, snow, frost)
- High impact resistance even in cold
- Good chemical resistance
- Higher temperature resistance than PLA/PETG (~95 °C)
- Matte, high-quality surface
- Can be smoothed with acetone
Technical Properties in Detail
| Property | Value | Meaning for Printing |
|---|---|---|
| Print Temperature (Nozzle) | 240–260 °C | Similar to ABS, higher than PETG |
| Bed Temperature | 90–110 °C | High – heated bed mandatory |
| Glass Transition Temperature (Tg) | ~95 °C | Higher than PETG, for heat-exposed parts |
| Tensile Strength | 40–50 MPa | Slightly lower than ABS, but tougher |
| Density | 1.07 g/cm³ | Slightly lighter than ABS |
| Impact Resistance | Very high | Robust even at low temperatures |
| UV Resistance | Excellent | Usable outdoors for years without degradation |
| Weather Resistance | Excellent | Resistant to rain, snow, frost, heat |
Pros and Cons of ASA
✅ Advantages
- Excellent UV resistance (no fading)
- Weather-resistant (outdoor-suitable)
- High impact resistance even in cold
- Heat-resistant (~95 °C)
- Matte, high-quality surface
- Smoothable with acetone (like ABS)
- Good chemical resistance
- Durable (years of outdoor use)
❌ Disadvantages
- Prone to warping (like ABS)
- Requires heated bed (90–110 °C)
- Fumes during printing (ventilation needed!)
- Enclosure recommended
- Harder to print than PLA/PETG
- More expensive than PLA/ABS
- Not food-safe
Optimal Print Settings for ASA
Base Settings (Guide Values)
| Parameter | Recommended Value |
|---|---|
| Nozzle Temperature | 245–255 °C (first layer: +5 °C) |
| Heated Bed | 95–105 °C |
| Print Speed | 40–70 mm/s |
| Fan (Part Cooling) | 0–20% (very little!) |
| Retraction (Direct Drive) | 1–3 mm @ 30–40 mm/s |
| Retraction (Bowden) | 4–6 mm @ 30–50 mm/s |
| Layer Height | 0.1–0.3 mm (0.2 mm standard) |
| Enclosure | Recommended (ambient temperature 30–40 °C) |
Troubleshooting: Common Print Errors
Warping (Distortion at Corners)
- Increase bed to 100–105 °C
- Use enclosure (no drafts!)
- Use Brim or Raft as adhesion surface
- Prepare print bed with adhesive (Magigoo, ABS-Slurry)
- Print first layer slower (15–20 mm/s)
- Turn fan completely off (0%)
Poor Layer Adhesion / Delamination
- Increase temperature (250–255 °C)
- Fan at 0% (max. 20% only for overhangs)
- Reduce print speed
- Use enclosure (increase temperature in build volume)
Stringing
- Lower temperature by 5 °C
- Optimize retraction (small steps)
- Dry filament (ASA absorbs moisture)
Cracks After Cooling
- Cooling too fast → leave printer closed after print
- Let cool slowly (30–60 minutes)
- Lower bed temperature gradually (don't turn off immediately)
ASA vs. Other Filaments: When to Use What?
| Property | ASA | ABS | PETG | PLA |
|---|---|---|---|---|
| UV Resistance | ✅ Excellent | ❌ Low | ⚠️ Medium | ❌ Low |
| Outdoor-suitable | ✅ Yes | ❌ No | ⚠️ Limited | ❌ No |
| Heat Resistance | ~95 °C | ~100 °C | ~80 °C | ~60 °C |
| Print Difficulty | ⭐⭐⭐ Hard | ⭐⭐⭐ Hard | ⭐⭐ Medium | ⭐ Easy |
| Warping | ⚠️ Medium | ❌ Strong | ✅ Low | ✅ Very low |
| Odor During Printing | ⚠️ Medium | ❌ Strong | ✅ Low | ✅ Minimal |
| Surface Quality | ✅ Matte, premium | ✅ Matte | ✅ Glossy | ⚠️ Glossy |
Decision Guide: Which Material When?
- Choose ASA for: Outdoor applications, UV exposure, automotive, garden furniture, weather-resistant parts
- Choose ABS for: Indoor applications with heat resistance, when UV stability is not needed
- Choose PETG for: Indoor functional parts without UV exposure
- Choose PLA for: Prototypes, decoration without mechanical stress
Application Areas for ASA
Ideally suited for:
- Outdoor Furniture: Garden chair components, planters, decoration
- Automotive: Spoilers, mirror parts, radiator grille, emblems
- Building Technology: Facade elements, ventilation grilles, covers
- Outdoor Electronics: Weather station housings, sensor protection covers
- Sports & Leisure: Drone frames, RC car bodies, boat accessories
- Agriculture: Spare parts, brackets, weather-resistant fixtures
- Solar Technology: Brackets, cable channels, mounting brackets
Not recommended for:
- ❌ Food contact (not food-safe)
- ❌ Medical implants
- ❌ High-precision dimensions (warping can affect tolerances)
- ❌ Beginner projects (PLA/PETG are easier)
Storage and Care of ASA Filament
ASA is hygroscopic and attracts moisture, which leads to bubble formation and poor print quality.
Symptoms of wet filament:
- Audible hissing during extrusion
- Bubble formation at the nozzle
- Stringing and uneven surface
- Brittle layers
Proper storage:
- In sealed bags with silica gel
- Dry box with dehumidifier (humidity <20%)
- At room temperature, protected from sunlight
Post-Processing: Acetone Smoothing
Like ABS, ASA can be smoothed with acetone vapor to achieve a glossy, smooth surface.
Acetone Smoothing Instructions:
- Place the print in a sealable container
- Put acetone in a separate small dish (not directly on the print!)
- Place both in the container, close
- Wait 15–60 minutes (depending on desired effect)
- Remove and let dry
Our ASA Filaments in the Shop
Frequently Asked Questions (FAQ)
What is the difference between ASA and ABS?
ASA is chemically similar to ABS, but with an acrylate rubber instead of butadiene. This makes ASA UV-resistant and weather-resistant, while ABS becomes brittle and fades under UV light. For outdoor applications, ASA is clearly superior.
How long does ASA last outdoors?
ASA is designed for years of outdoor use. In the automotive industry, ASA parts are calculated for a lifespan of 10+ years. Color and mechanical properties remain stable even after years of sun exposure.
Do I absolutely need an enclosure for ASA?
Not mandatory, but strongly recommended. Without an enclosure, the risk of warping is significantly higher. Small parts work without, but for larger prints (>10 cm), an enclosure is almost indispensable.
Can I print ASA without ventilation?
No, not recommended. ASA produces fumes (styrene-like) that can be harmful. Always print in well-ventilated rooms or use an activated carbon air filter.
Is ASA recyclable?
Theoretically yes, practically ASA prints are usually not accepted by recycling centers (contamination, dyes). In Switzerland, ASA goes in regular household waste.
Related Guides
- ABS Filament: Heat-resistant and robust
- PETG Filament: Properties and applications
- PLA Filament: The all-rounder
- PA (Nylon): Extremely robust and wear-resistant
Note: The information in this guide is based on typical properties of ASA filaments. Specific values may vary by manufacturer. Always consult the technical data sheets.