ASA for outdoor parts: UV claims, heat resistance and the enclosure question
Short answer
ASA prints like ABS: 240–270 °C nozzle, 75–115 °C bed and an enclosure or a tall skirt for anything large [3, 5, 6]. Its makers sell it for outdoor parts because it resists UV and yellowing better than ABS [4, 7]. Heat deflection at 0.45 MPa is 93–103 °C in the three data sheets [3, 5, 6]. None of them publishes a UV-aging test, so the outdoor claim rests on the makers' descriptions.
Published ranges at a glance
The span of values that makers publish for 8 products (ASA) in the filament database, by grade. Every product, with its source, is listed in the full table below the guide.
| Grade | Products | Nozzle °C | Bed °C | Drying °C | HDT at 0.45 MPa, °C |
|---|---|---|---|---|---|
| ASA | 7 from 7 brands | 230–280 | 70–115 | 70–85 | 88–103 |
| ASA-GF | 1 from 1 brand | 250–270 | 100–110 | 70–80 | 98 |
What ASA changes compared with ABS
ASA keeps the acrylonitrile and styrene of ABS but replaces butadiene with an acrylate component [4]. Bambu Lab says the acrylate improves weather adaptability and UV resistance while keeping ABS’s impact resistance and processability [4]. Prusa calls ASA the successor to ABS: more UV resistant, less warping and less odor [1].
The printing behavior stays close to ABS. Bambu Lab’s product page says both materials share the same warping tendency and the same enclosed-printer requirement for large or dense models [4]. The ABS vs ASA comparison lines the two up side by side.
Print settings from the data sheets
| Setting | Bambu ASA | Polymaker ASA | Prusament ASA |
|---|---|---|---|
| Nozzle | 240–270 °C | 230–260 °C | 260 ± 10 °C |
| Bed | 80–100 °C | 75–95 °C | 110 ± 5 °C |
| Part cooling | 0–80% | off | 30% (0–50%) |
| Chamber | 45–60 °C | enclosure needed | not published |
| Print speed | below 250 mm/s | 50–200 mm/s | up to 200 mm/s |
| Drying | 80 °C, 8 h | 70 °C, 7 h | 80 °C, 4 h (Prusa KB) |
The Prusa Knowledge Base gives 260 °C for the nozzle and 105 °C for the first layer, 110 °C after that, on a smooth or powder-coated PEI sheet with glue stick [1]. Prusa also warns against putting acetone, or ABS or ASA dissolved in acetone, on its powder-coated sheets [1]. Bambu Lab lists 90–100 °C on its Engineering, Smooth PEI and Textured PEI plates, with glue [9].
The bed range is wide across brands: from 75 °C at the low end of Polymaker’s range to 115 °C at the top of Prusament’s. Each maker’s figure assumes its own plate and printer, so start from the data sheet that matches your filament. The drying chart collects the drying values.
Enclosure, warping and cooling
ASA warps less than ABS [1], but its makers still treat warm surroundings as part of the setup. Prusa lists significant warping as ASA’s main disadvantage and says an enclosure is necessary for large parts [1]. Without one, Prusa suggests PrusaSlicer’s draft shield (Print Settings, Skirt and brim), which builds a wall around the object to keep it warmer [1].
The Prusament data sheet adds two specific measures: a skirt as tall as the printed part, and a brim of 3 mm or more to hold the edges and corners of larger objects [6]. The Prusament product page notes that larger ASA parts can still shrink and detach even with the bed at 110 °C [7]. For a list of fixes, see the warping guide.
Polymaker’s wiki gives ASA the same preparation as ABS: an enclosed printer, a 90–100 °C bed held for 10 minutes before printing so the chamber can warm up, and the fan off if layers or the first layer do not bond [8]. It notes a trade-off: slower and hotter printing improves layer adhesion but makes overhangs look worse [8].
Cooling is the setting where sources disagree most. Polymaker says off. Prusa Polymers specifies 30%, raised for overhangs and bridges and turned off for large parts without bridges [6]. Bambu Lab allows 0–80% [3].
Prusa also flags a printer-side risk: printing a lot of ASA in an unventilated enclosure can deform the fan shroud and plastic extruder parts over time [1].
UV and outdoor use: what is published
All three makers market ASA for outdoor parts:
- Bambu Lab’s data sheet describes exceptional UV, weather, mechanical and thermal resistance, and lists plant signs, mailboxes and wind vanes as uses [3]. Its product page claims resistance to UV, oxidation and aging, protecting against breakage and color degradation outdoors [4].
- Prusament’s page calls ASA UV stable and says it keeps its toughness and does not turn yellow over long outdoor use [7].
- Polymaker describes improved weather resistance and UV resistance compared with ABS [5].
None of these three data sheets names a weathering or UV-aging test method, an exposure time or a retained-property result. The outdoor suitability therefore rests on the manufacturers’ descriptions, not on published test data. Prusa’s ABS article provides the contrast: ABS parts used outdoors turn yellowish and more brittle over time [2].
Heat resistance and strength
| Product | HDT at 0.45 MPa | HDT at 1.80 MPa |
|---|---|---|
| Bambu ASA | 100 °C | 92 °C |
| Polymaker ASA | 103 °C | 100 °C |
| Prusament ASA | 93 °C | 86 °C |
Bambu Lab’s product page compares its ASA, ABS and PC directly. ASA has the higher heat deflection (100 °C against 87 °C for ABS) and slightly higher XY impact strength (41.0 against 39.3 kJ/m²), but lower Z-direction impact strength, which Bambu labels layer adhesion: 4.9 kJ/m² against 7.4 kJ/m² for ABS [4]. For a part loaded across its layers, that row is the more relevant one. The heat resistance comparison shows other brands.
Fumes and ventilation
Safety: Prusa says ASA releases potentially dangerous fumes containing styrene and that printers should run in a well-ventilated area, without a draft around the print [1]. Bambu Lab’s ASA page asks for a well-ventilated area or an effective air filtration or exhaust system [4]. Prusa describes its Advanced Filtration System for enclosed printers as a HEPA filter for ultrafine particles plus activated carbon for vapors, and names ASA among the materials that release more particles and odor [11].
Other uses: ASA as a support material
ASA also appears as a support material for engineering filaments. Bambu Lab recommends its ASA as the support for PA6-CF, PET-CF, PAHT-CF, PPA-CF and PPS-CF. Because ASA bonds weakly to PA6-CF and PAHT-CF, it suggests printing both the support core and interface in ASA with those two [12]. Since ASA is not a dedicated support filament, Bambu Studio does not generate the support parameters automatically [12].
Bambu Lab’s AMS compatibility table lists ASA as compatible with both the AMS and AMS lite, unlike ABS, which is not recommended in the AMS lite [9].
All 8 products in the database
| Source | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Bambu Lab | ASA | ASA | 240–270 | 80–100 | 1.05 | 80 °C, 8 h | 100 °C @ 0.45 MPa 92 °C @ 1.8 MPa | not published | [3] |
| Elegoo | ASA | ASA | 240–270 | 90–100 | 1.09 | 75–85 °C, 8 h | 99 °C @ 0.45 MPa | not published | [13] |
| eSUN | ASA+ | ASA | 240–270 | 90–110 | 1.00 | not published | 88 °C @ 0.45 MPa | not published | [14] |
| Overture | ASA | ASA | 240–270 | 70–95 | 1.14 | 75 °C, 7 h | not published | not published | [15, 16] |
| Polymaker | ASA | ASA | 230–260 | 75–95 | 1.13 | 70 °C, 7 h | 103 °C @ 0.45 MPa 100 °C @ 1.8 MPa | not published | [5] |
| Prusament | ASA | ASA | 250–270 | 105–115 | 1.07 | 80 °C, 4 h | 93 °C @ 0.45 MPa 86 °C @ 1.8 MPa | not published | [6, 10] |
| Siraya Tech | Fibreheart ASA-GF | ASA-GF | 250–270 | 100–110 | 1.10 | 70–80 °C, 4–6 h | 98 °C @ 0.45 MPa 94 °C @ 1.8 MPa | not published | [17] |
| Sunlu | ASA | ASA | 250–280 | 80–100 | 1.04 | 80 °C, 6–8 h | 101 °C @ 0.45 MPa | not published | [18, 19] |
Questions
Can ASA be printed without an enclosure?
Small parts, sometimes. Prusa says an enclosure is necessary for large parts and suggests PrusaSlicer's draft shield as an alternative; the Prusament ASA data sheet suggests a skirt as tall as the part [1, 6]. Polymaker lists an enclosure as needed, and Bambu Lab does not recommend ASA on its open-frame printers [5, 9].
Sources
- ASA. Prusa Knowledge Base. Manufacturer documentation. Temperatures, UV and outdoor use, enclosure and draft shield, fumes, partial hygroscopy. Accessed October 12, 2026.
- ABS. Prusa Knowledge Base. Manufacturer documentation. ABS parts used outdoors turn yellowish and brittle. Accessed October 12, 2026.
- Bambu ASA Technical Data Sheet (V3.0). Bambu Lab. Technical data sheet. Print settings, chamber 45–60 °C, HDT, UV and outdoor description. Accessed October 12, 2026.
- ASA product page. Bambu Lab. Product page. UV and aging claims, ASA vs ABS vs PC comparison table, odor and safety tips. Accessed October 12, 2026.
- Polymaker ASA Technical Data Sheet (V6.0). Polymaker. Technical data sheet. Nozzle 230–260 °C, bed 75–95 °C, fan off, enclosure needed, HDT. Accessed October 12, 2026.
- Prusament ASA Technical Datasheet (v1.1, 20-05-2024). Prusa Polymers. Technical data sheet. Nozzle 260 ± 10 °C, bed 110 ± 5 °C, fan 30% (0–50%), skirt and brim advice, HDT. Accessed October 12, 2026.
- Prusament ASA. Prusament. Product page. UV stability, no yellowing claim, warping at 110 °C bed, enclosure or tall skirt. Accessed October 12, 2026.
- Polymaker Material Print Tips. Polymaker Wiki. Manufacturer documentation. Enclosed printer, bed preheat, hot-and-slow trade-off for ASA. Accessed October 12, 2026.
- Filament guide: printer, nozzle, AMS, build plate, glue compatibility and required parameters. Bambu Lab Wiki. Manufacturer documentation. Enclosed printer recommendation, plate temperatures, AMS compatibility, drying. Accessed October 12, 2026.
- Drying filament. Prusa Knowledge Base. Manufacturer documentation. Prusament ASA drying at 80 °C for 4 hours. Accessed October 12, 2026.
- Advanced Filtration System (glossary). Prusa Knowledge Base. Manufacturer documentation. HEPA and activated carbon filtration for ASA, ABS and nylon. Accessed October 12, 2026.
- Support (support filament and support settings). Bambu Lab Wiki. Manufacturer documentation. ASA as a support material for PA-CF, PAHT-CF, PET-CF and other engineering filaments. Accessed October 12, 2026.
- ELEGOO ASA product page: Specifications. ELEGOO. Product page. Specifications section: drying, recommended printing settings, physical properties (density, Vicat, HDT at 0.45 MPa) and X-Y/Z mechanical properties; no test standards named. Accessed October 12, 2026.
- Product Comparison. eSUN (official store). Product page. Values appear after choosing a product in the comparison tool: density, HDT at 0.45 MPa, melt flow index, Z tensile strength, X-Y flexural and Izod values, extruder and bed temperature, fan, print speed, build surfaces and printing recommendations; no test standards named. Accessed October 12, 2026.
- OVERTURE ASA Technical Data Sheet (Version 5.1, August 2024). Overture 3D. Technical data sheet. Recommended printing conditions, physical and mechanical properties of 3D-printed specimens (100% infill). Accessed October 12, 2026.
- Overture ASA 3D Printer Filament 1.75mm (product page). Overture 3D. Product page. Specs tab drying setting. Accessed October 12, 2026.
- Siraya Tech Fibreheart ASA-GF TDS. Siraya Tech. Technical data sheet. Print settings, chamber temperature, drying, property data. Accessed October 12, 2026.
- SUNLU ASA Technical Data Sheet (SL-TE-WI-059, version A/1). SUNLU. Technical data sheet. Recommended printing parameters with drying temperature; ISO 75 HDT at 0.45 MPa, ISO 306 Vicat, ISO 1183 density and ISO 527-2 X-Y tensile results from printed specimens. Accessed October 12, 2026.
- Material Performance Comparison. SUNLU Wiki. Manufacturer documentation. Detailed specification table for the SUNLU line, including drying temperature and drying time per product. Accessed October 12, 2026.