The spec, the outdoor story, the honest limits, and where ASA actually wins · cross-checked against the manufacturer's TDS V5.4, written by the team that prints it.
Custom ASA 3D printing service · UK · quoted in 6 hours.
Stronger than ABS and holds its colour and strength for years outdoors · no painting needed.
Four quick visuals. Start with which material to pick and where ASA works; the engineering detail is at the end if you want it.
ASA's polyacrylate rubber phase has no UV-reactive bonds, so the polymer stays colour-stable and structurally intact through years of UK weather. ABS yellows within months and surface-cracks by year 2. The engineering-commodity outdoor default · used in automotive exterior, garden equipment, satellite dishes, signage.
ABS's butadiene rubber phase has reactive carbon-carbon double bonds (C=C). UV-B radiation snaps those bonds · ABS yellows and surface-cracks within months. ASA replaces butadiene with polyacrylate (no C=C in the backbone), so the polymer stays colour-stable across years of outdoor service.
"James handled the 3D printing for a functional heat resistant component we needed in batch production. He helped dial in the prototype first with their design service, then produced the final batch with really consistent results. Super fast 3D print turnaround and great quality across all the 3D printed parts. Will 100% be coming back."
"We needed a sit-in F1-car for an exhibition to showcase our new racing game. 3D Printing Express took our CAD, optimised it for strength and weight as we had no idea how it all worked! Turned out beautifully. They colour matched the finish and was looking like the real deal. On show day the cockpit ran non-stop, adults and kids jumped in. Multiple visitors asked who built it."
"We ordered a batch of 100 PA-12 parts from 3D Printing Express and could not be happier. Every part arrived consistent, dimensionally accurate, and ready for use straight from the box. The PA-12 gave us the strength and stability we needed for functional testing, with minimal post-processing required. Delivery was on time, communication was excellent, and their QC clearly made a difference."
31% stronger than ABS (33.4 MPa). The polyacrylate rubber phase doesn't hurt the rigid SAN matrix · ASA is the stronger styrenic.
3°C higher than ABS's 100°C, 25°C higher than PETG. Holds a sun-warmed enclosure, automotive exterior, garden housing through UK summers comfortably.
4× tougher than PETG (2.6) and PLA (3.3) · about 60% of ABS's 18.0. Polyacrylate rubber phase is less impact-tough than butadiene but trades that for UV stability.
The ASA wedge · polyacrylate rubber has no UV-reactive C=C bonds. Where ABS yellows in months, ASA stays colour-stable across years of UK weather.
ASA earns its place whenever sustained outdoor service is required · the engineering-commodity default for multi-year weather-exposed parts, signage, automotive exterior, marine fittings, and any application where UV-driven yellowing would kill ABS.
ASA's strengths are UV stability + heat resistance + styrenic engineering performance · its weaknesses are styrene VOC emissions, chamber printer requirement, lower impact than ABS, and acetone / chlorinated-solvent exposure. Pick a different filament if any of these apply.
Multi-year UV stability means the part stays colour-stable through summers · the right material for retail signage, exhibition pieces left outside, way-finding displays. ABS's butadiene yellows within months; ASA holds for years.
ASA is the production polymer for automotive exterior parts — the industry default for UV-stable visible trim. Printing prototypes in ASA keeps both chemistry and UV stability consistent with the production injection-moulded part.
UK garden and marine environments are wet and sunlit · ASA handles both. Tolerates salt-spray, UV, and water-splash service that would degrade ABS within a season.
HDT 103°C combined with multi-year UV stability handles parts that see both direct sun heat and sustained UV exposure. The right material when a painted ABS box would peel and yellow inside two seasons.
A side-by-side of the three styrenic commodity thermoplastics, plus PETG for context. ASA's wedge is UV stability + slightly higher strength than ABS · the engineering-commodity outdoor default. ABS wins on impact and acetone smoothing; PETG wins on ease of print.
All numerical values from manufacturer Technical Data Sheets · injection-moulded ISO test specimens (ISO 527 tensile, ISO 75 HDT, ISO 179 Charpy notched). Outdoor service is qualitative · TDS doesn't publish a UV-stability multiplier, so we use the verifiable language of multi-year (ASA) vs months (ABS, PETG uncoated).
| Property | ASA (here) | ABS | PETG |
|---|---|---|---|
| Tensile strength XY | 43.8 MPa | 33.4 MPa | 50.8 MPa |
| Stiffness (Young's modulus XY) | 2379 MPa | 2247 MPa | 2117 MPa |
| Charpy notched impact | 10.3 kJ/m² | 18.0 kJ/m² | 2.6 kJ/m² |
| Elongation at break XY | 6.7% | 17.9% | 8.4% |
| Heat deflection (HDT 0.45) | 103°C | 100°C | 78°C |
| Glass transition (Tg) | 98°C | 101°C | 81°C |
| Outdoor / UV service | Multi-year | Months only | 6-12 months uncoated |
| Density | 1.13 g/cm³ | 1.04 g/cm³ | 1.25 g/cm³ |
| Acetone smoothing | Partial | Yes · vapour or brush | No |
| Solvent welding (acetone) | Good | Excellent · fuses to single mass | Limited |
| Chamber printer required | Yes · 40-50°C ambient | Yes · 40-50°C ambient | No |
| VOC during print | Higher (styrene) · ventilation required | Higher (styrene) | Lower |
| Cost per kg (filament) | £35-50 | £30-45 | £25-40 |
| Best for | Sustained outdoor · automotive exterior · weather-exposed signage | Indoor impact · acetone-smoothed · solvent-welded | Water-contact · food-adjacent · ease of print |
This is 3DPE's standard process for ASA · the equipment and the dried-filament discipline are included, no surcharge. Slicer profile and orientation are tuned per part at quote stage.
File or sketch in. Tell us colour, finish, where outdoors the part lives, what weather it sees.
Reviewed inside 24 hours. You get a per-unit cost and colour confirmation.
Before we print, we flag wall thickness, warp-prone geometry, chamber orientation, and UV-exposed surface area.
Filament dried at 70°C for 7h · enclosed chamber printer with 40-50°C ambient · extraction ventilation for styrene VOCs.
Sand to spec · 2K spray paint for RAL match · we typically skip acetone-smoothing on ASA to preserve UV-stable surface chemistry.
Tracked UK courier, tracking number sent the moment it leaves.
Lead times start when CAD is signed off and colour is confirmed · CAD round-trips on rev requests can extend the clock. Custom RAL colour matching can add 1-2 days for filament procurement. UV-overcoat adds 48h cure cycle.
Production batch of weather-exposed signage printed in standard ASA · enclosed chamber for warp-free print, 2K-painted in custom RAL brand colour, UV-clear-coated for added longevity. The ASA-specific combination that survives years of UK sun where painted ABS would yellow and peel inside two seasons.
ASA is acrylonitrile styrene acrylate · an amorphous styrenic terpolymer where the butadiene rubber phase used in ABS is replaced with a polyacrylate rubber phase. Acrylate has no reactive carbon-carbon double bonds (C=C) in its backbone · so UV-B radiation cannot snap and degrade the polymer the way it does ABS. The result: the same impact toughness, stiffness, and heat resistance class as ABS, but multi-year outdoor service where ABS yellows and chalks within months. Tensile strength 43.8 MPa XY (ISO 527), HDT 103°C at 0.45 MPa (ISO 75), Young's modulus 2379 MPa, Charpy notched 10.3 kJ/m² (ISO 179). Density 1.13 g/cm³. The engineering-commodity default for sustained outdoor parts, signage, automotive exterior trim, and weather-exposed enclosures.
"ASA is the material we reach for whenever the part lives outside. Sign-makers, automotive prototypers, garden-equipment brands, marine fitters · all the same chemistry need. The wedge is one chemical bond: butadiene has a reactive C=C double bond that UV snaps, acrylate doesn't. That's the whole outdoor story, condensed into one molecular swap. We print it in a chamber like ABS, ventilate the styrene like ABS, but the part survives a UK summer where painted ABS would peel inside two seasons."
Three questions worth answering before specifying ASA: why one molecular swap delivers multi-year UV stability, what the chamber requirement actually means, and where ASA sits against ABS, PETG and PC.
ASA keeps ABS's SAN-matrix-with-rubber-particles architecture · just swaps polybutadiene rubber for polyacrylate. Polyacrylate has no C=C double bonds, so UV-B radiation doesn't break the rubber phase. The result: the same engineering performance as ABS with multi-year outdoor stability. Impact toughness drops slightly (Charpy 10.3 vs ABS 18.0 kJ/m²) because polyacrylate is less impact-tough than polybutadiene, but UV stability is the wedge.
ASA contracts as it cools from 230-260°C extrusion · without a heated chamber holding 40-50°C ambient, the same warping mechanism as ABS kicks in (bottom of the part contracts while the top is still hot · layer delamination and bed lift). We print every ASA job in a chamber printer; open-bed ASA is the most common DIY-failure mode.
ASA Tg 98°C is comparable to ABS's 101°C, 17°C higher than PETG and 37°C higher than PLA. HDT 100°C at 1.8 MPa is the structural ceiling. The amorphous styrenic backbone holds the part rigid through a UK summer outdoor surface (~60-70°C) comfortably.
ABS's butadiene rubber phase has reactive carbon-carbon double bonds (C=C) in every repeat unit of the polybutadiene chain. UV-B radiation (290-315 nm wavelength) has just enough energy to break those C=C bonds via photo-oxidative scission. Once a bond snaps, the rubber phase oxidises, the colour shifts toward yellow, and the surface micro-cracks as the polymer chain breaks down. This degradation accelerates with each summer of UV exposure · ABS without UV overcoat yellows within months and surface-cracks by year 2.
ASA replaces polybutadiene with polyacrylate · a rubber chemistry where the backbone is saturated (no C=C bonds). Without a UV-reactive bond for sunlight to break, the polymer stays structurally intact. The styrene-acrylonitrile (SAN) matrix is identical to ABS, so mechanical and thermal performance carries over. Only the rubber phase chemistry changes · but that one swap is the entire UV story. ASA is what you choose when "this part will live outside" appears anywhere in the brief.
ASA prints at 230-260°C and contracts as it cools · same warping mechanism as ABS. With open-air cooling, the bottom of the part (cooled, stabilised) tries to maintain its dimensions while the top (still hot) wants to shrink as it cools. The result is internal stress that pulls the part off the bed (corner lift, warping) or splits layer junctions (delamination). PETG and PLA cool more uniformly and don't have this problem.
The fix is straightforward · an enclosed chamber holding 40-50°C ambient temperature for small parts and 60°C+ for large parts. The slow, equalised cooling prevents the thermal gradient that drives warping. We print every ASA job in a chamber printer. The TDS lists 'Closure Chamber Needed (ambient temperature)' as a recommended printing condition · open-bed ASA is the most common DIY-failure mode.
ASA is the engineering-commodity outdoor default. Versus ABS (indoor sibling, more impact, acetone-smoothable, no UV stability), ASA wins for anything that sees sustained sunlight. Versus PETG (water-contact, food-adjacent, no chamber needed), ASA wins for parts that see UV more than water · same chamber-printer overhead as ABS. Versus UV-stabilised PC (engineering outdoor, ~130°C HDT, much higher impact, harder to print at 260-290°C), ASA is the lower-cost commodity choice when you don't need PC's extra heat tolerance or impact resistance.
Decision in one line: pick ASA when the part lives outdoors and ABS's price point isn't enough to offset its UV failure mode.
Values measured to the ISO standards cited in the right-hand column. Directly comparable to other engineering thermoplastics.
| Property | XY · print plane | Z · build axis | Unit | Standard |
|---|---|---|---|---|
| Mechanical | ||||
| Tensile strength | 43.8 | 32.0 | MPa | ISO 527 |
| Young's modulus | 2379 | 1965 | MPa | ISO 527 |
| Elongation at break | 6.7 | 1.65 | % | ISO 527 |
| Flexural strength (XY) | 73.4 | MPa | ISO 178 | |
| Flexural modulus (XY) | 3206 | MPa | ISO 178 | |
| Charpy impact (notched, XY) | 10.3 | kJ/m² | ISO 179 | |
| Charpy impact (notched, Z) | 6.7 | kJ/m² | ISO 179 | |
| Thermal | ||||
| Heat deflection (HDT @ 0.45 MPa) | 103 | °C | ISO 75 | |
| Heat deflection (HDT @ 1.8 MPa) | 100 | °C | ISO 75 | |
| Glass transition temperature (Tg) | 98 | °C | DSC, 10°C/min | |
| Vicat softening temperature | 105 | °C | ISO 306 | |
| Physical | ||||
| Density | 1.13 | g/cm³ @ 23°C | ISO 1183 | |
| Melt index | 25 | g/10min | 220°C, 10kg | |
| Equilibrium water absorption | 0.40 | % | manufacturer test | |
| Tensile anisotropy ratio | 1.37× | XY/Z | derived from ISO 527 | |
| Chemical resistance · manufacturer-rated | ||||
| Weak acids | Good | · | manufacturer TDS | |
| Strong acids | Poor | · | manufacturer TDS | |
| Weak alkalis | Good | · | manufacturer TDS | |
| Strong alkalis | Fair | · | manufacturer TDS | |
| Oils and grease | Good | · | manufacturer TDS | |
| Outdoor service · qualitative | ||||
| UV stability | Multi-year (polyacrylate rubber phase) | · | polymer chemistry · acrylate-vs-butadiene UV resistance | |
| Outdoor service vs ABS | Years vs months (no UV-reactive C=C bonds) | · | qualitative comparison | |
| Process · supply | ||||
| Print temperature range | 230-260 | °C | manufacturer printing guide | |
| Bed temperature | 75-95 | °C | manufacturer printing guide | |
| Chamber required | Yes · 40-50°C ambient (small parts) | · | manufacturer printing guide | |
| Pre-print drying | 70°C for 7 hours | · | manufacturer printing guide | |
| Acetone smoothable | Partial · less clean than ABS | · | styrenic chemistry + polyacrylate phase | |
| Stock colour range | 10+ colours | · | workshop stock | |
| Custom RAL match | Yes (1-2 day procurement) | · | on request | |
ASA's anisotropy is 1.37× XY/Z (43.8/32.0 MPa per TDS V5.4) · more directional than ABS (1.12×) or PETG (1.19×), in the same range as PLA (1.29×). For load-bearing parts orient XY-direction load paths; Z-axis features carry only 73% of the XY tensile.
ASA's higher tensile (43.8 MPa) than ABS and moderate Charpy notched (10.3 kJ/m²) mean thin walls handle impact between ABS and PLA. The values shown follow the Hubs / Protolabs Network FDM minimums (0.8 mm supported, 2.0 mm minimum feature) · we DFM-check the wall thickness against your part's load case at quote stage.
45° is the slicer-default support threshold across every major FDM tool (Hubs / Protolabs Network) · ASA's chamber-print environment means cooling is slower than PLA or PETG, so steep overhangs sag more without aggressive support. We DFM-check overhangs at quote stage and recommend orientation.
ASA contracts ~0.5% from print temperature to room temperature · chamber printing makes that contraction uniform and predictable, same as ABS. Exact tolerance depends on part size, geometry, and calibration · we confirm achievable tolerance against your CAD at quote stage.
Removes 0.1-0.3 mm per surface · pre-paint prep or stand-alone hand-feel polish.
Adhesion-promoting primer + RAL-matched 2K topcoat + UV-resistant clear coat. Adds 0.1-0.2 mm per surface plus 48h cure. The native ASA polymer is already multi-year UV-stable; the UV-clear topcoat extends colour stability further for sign-grade outdoor parts.
ASA takes paint cleanly with adhesion-promoting primer. Adds 0.05-0.15 mm per surface · sand to 800 grit, primer + topcoat. We typically use the 2K paint route on ASA rather than acetone-smoothing · keeps the UV-stable surface chemistry intact for outdoor service.
ASA's UV stability is built into the polymer · no overcoat, no clear lacquer, no special post-process required. The part as it leaves the printer survives years of sustained UK weather. Optional UV-clear topcoat extends colour stability further for sign-grade visibility, but bare ASA is already the engineering-commodity outdoor default.
Every value on this page traces to an ISO test method — the manufacturer's V5.4 EN Technical Data Sheet (TDS). UV stability is reported qualitatively rather than with unverified outdoor-lifetime figures.
No offshore subcontracting. Files, prints, and couriers all stay in the UK · and we run every ASA job in an enclosed-chamber printer with extraction ventilation to handle styrene VOCs.
Send three things: where the part lives (outdoor exposure, UV hours, weather seen), what it does (functional / load-bearing / signage), and finish (custom RAL, UV-clear, painted, as-printed). our team come back inside 24 hours · if ABS, PETG, PC, or another material fits better, we say so.
our team review every brief before quote. No ticket queue, no account managers.
According to the Polymaker ASA TDS, ASA delivers tensile XY 43.8 ± 0.8 MPa per ISO 527 with HDT 103 °C @ 0.45 MPa and Tg 98 °C · UV-stable outdoor amorphous grade.
ASA is acrylonitrile styrene acrylate · the UV-stable cousin of ABS. The chemistry is nearly identical except the butadiene rubber phase used in ABS is replaced with a polyacrylate rubber phase. Butadiene has reactive carbon-carbon double bonds (C=C) in every repeat unit · UV-B radiation snaps those bonds, the rubber phase oxidises, and ABS yellows and surface-cracks within months outdoors. Acrylate has no C=C bonds in its backbone, so the polymer survives years of direct sunlight. ASA keeps the impact toughness, stiffness, and heat resistance of ABS (43.8 MPa tensile, 103°C HDT, 10.3 kJ/m² Charpy notched · all per TDS V5.4) and loses the single feature that made ABS unsuitable outdoors.
Multi-year. ASA is the engineering-commodity default for sustained outdoor service. Industry use cases include automotive exterior trim (door mirrors, grilles), outdoor signage, marine fittings, garden equipment housings, satellite dish components. The TDS doesn't publish a specific outdoor lifetime, and we use the qualitative "multi-year" language rather than quote unverified specifics. For comparison: ABS yellows within months in UK summer sun · ASA stays colour-stable across years.
ASA is meaningfully stronger in tensile and stiffness · TDS V5.4 ASA vs V5.5 ABS: tensile 43.8 vs 33.4 MPa (31% higher), Young's modulus 2379 vs 2247 MPa (5% higher), flexural strength 73.4 vs 56.2 MPa (31% higher). ABS wins on impact toughness (Charpy notched 18.0 vs 10.3 kJ/m² · 75% higher). Heat resistance is comparable (ASA HDT 103°C vs ABS 100°C). Pick ASA for strength + outdoor; pick ABS for maximum impact (or for acetone-smoothing, which ABS does cleaner).
Partially. ASA's styrene component dissolves in acetone like ABS does, but the polyacrylate rubber phase responds differently · the result is a less uniform finish than acetone-smoothed ABS. Vapour smoothing works (cleaner) than brush application. For glass-smooth ASA we typically sand-and-paint rather than acetone-smooth · the result holds the multi-year UV-stable surface intact, where acetone smoothing can compromise the surface chemistry slightly.
Tg sits at 98°C · comparable to ABS's 101°C. HDT is 103°C at 0.45 MPa and 100°C at 1.8 MPa per TDS V5.4. Vicat softening 105°C. An ASA part in a hot car dashboard (~70°C in summer) holds its shape comfortably; outdoor sunlit surfaces in the UK (60-70°C summer max) sit well within envelope. Engine-bay parts above 110°C creep · for that switch to PC, PC-ABS, or PA12-CF (HDT 130°C+ class).
ASA emits styrene and other VOCs at print temperature (230-260°C). Similar VOC profile to ABS · higher than PLA or PETG. We print ASA in an enclosed chamber with extraction ventilation · this is the workshop reason chamber printers exist. For a hobbyist printer in a flat without ventilation, PETG or PLA is the safer choice. ASA's environmental advantage isn't VOC reduction · it's UV stability of the finished part.
ASA prints at 230-260°C and cools rapidly as each layer extrudes · same warping mechanism as ABS. An enclosed chamber holds ambient temperature at 40-50°C for small parts and 60+ for large parts, slowing cooling and equalising the thermal gradient. The TDS lists "Closure Chamber Needed (ambient temperature)" as a recommended printing condition. Open-bed ASA warps badly · this is the most common DIY failure mode.
Mixed, comparable to ABS. Per TDS · GOOD against weak acids, weak alkalis, and oils/grease. FAIR against strong alkalis. POOR against strong acids. ASA dissolves in acetone, MEK, and chlorinated solvents (same as ABS). For sustained chemical-service parts use PA12 or PP. ASA's design wedge isn't chemical resistance · it's UV stability.
| Chemical / family | Resistance | Notes |
|---|---|---|
| Weak acids (acetic, citric, dilute organic) | Good | Manufacturer TDS rating |
| Strong acids (sulphuric, HCl, nitric) | Poor | Manufacturer TDS rating · polymer chain breakdown |
| Weak alkalis (dilute soap, mild bleach) | Good | Manufacturer TDS rating · short-cycle wash-down |
| Strong alkalis (caustic soda, ammonia) | Fair | Manufacturer TDS rating · short-term only |
| Oils and grease | Good | Manufacturer TDS rating · sustained contact OK |
| Cold water | Excellent | Low water absorption (0.40% equilibrium) |
| Hot water (sustained > 80°C) | Limited | Approaches HDT · creep over months |
| Steam autoclave (121°C) | Fails | Above HDT · parts deform · choose PEEK / PPSU |
| Salt water / marine spray | Good | UV-stable polymer + low water absorption · marine-fitting grade |
| Alcohols (IPA, ethanol) | Good | Surface cleaning, brief contact safe |
| Acetone, MEK (ketones) | Dissolves | Same chemistry attack as ABS |
| Toluene, xylene (aromatic hydrocarbons) | Dissolves | Strong attack |
| Petrol, diesel (brief) | Limited | Brief contact OK · sustained attacks the polymer |
| Chlorinated solvents (DCM, chloroform) | Dissolves | Industrial solvents |
| UV exposure (UK outdoor, years) | Excellent | The ASA wedge · polyacrylate rubber has no UV-reactive C=C bonds |
| UV exposure (intense / equatorial) | Good | Multi-year service in higher-UV environments · pair with UV-clear topcoat for sign-grade longevity |
| Outdoor sheltered | Excellent | Indoor / weather-protected service trivial |
| Food contact | No | Styrene migration concern · use PETG with food-safe overcoat for food-adjacent |
First five rows are direct manufacturer TDS ratings. Remaining rows reflect industry-typical ASA behaviour and 3DPE workshop experience. For sustained chemical service beyond water and oils, switch material to PA12 or PP depending on the exposure.
ASA wins decisively for outdoor. The butadiene rubber phase in ABS contains carbon-carbon double bonds that absorb UV-B radiation, snap, and oxidise. The result on ABS exposed to UK summer sunlight: yellowing within months, surface chalking by year 1, micro-cracking by year 2. ASA's polyacrylate rubber phase has no C=C bonds; the polymer stays colour-stable and structurally intact for years. For outdoor signage, garden fittings, satellite dishes, automotive exterior · ASA is the engineering-commodity default.
Yes · ASA bonds well like ABS. Solvent welding with acetone works (less perfectly than ABS due to the acrylate phase, but the joint is still stronger than mechanical fastening). 2-part epoxy, cyanoacrylate, polyurethane adhesives all work cleanly. Mechanical fasteners with heat-set inserts (≈ 260°C iron temp per CNC Kitchen) for assemblies. For multi-part outdoor assemblies, paint over the joint to protect from UV exposure at the seam.
Filament cost is roughly £35-50/kg for stock-colour ASA · slightly above ABS (£30-45/kg) due to the more complex polyacrylate-rubber chemistry. Still well below engineering composites like PA12-CF (£90-130/kg). The total quote depends on print time + post-processing more than filament cost · ASA chamber-printer time runs comparable to ABS. For UV-stable production parts, ASA's price premium pays back in service life vs painted ABS that needs repainting every 2-3 years.
Different tradeoffs. ASA is the commodity outdoor default · multi-year UV stability, easy to print (in chamber), 103°C HDT, paintable. UV-stabilised PC is the engineering outdoor upgrade · higher HDT (~130°C), clearer/transparent grades possible, much higher impact toughness, but harder to print (260-290°C nozzle, larger chamber required). For most outdoor service parts ASA is the right answer; pick PC when you also need engineering-grade impact or optical clarity.
You'll hear back from our team within 24 hours · with material-fit check, colour confirmation, UV-overcoat recommendation if relevant, and lead time on every quote.