Thankyou for taking the time to read our guide on 3D printing ASA. This article has been written to provide both printing and troubleshooting tips along with tips for post-printing processes like painting and support removal. We have highlighted important topics with a star (*) so please don't feel intimidated as sections in this guide may not be relevant to everyone, - Matt Tyson, 3D Printing Solutions
This user guide was last updated - 25th October 2019
ASA is a UV and weather resistant material sharing similar printing characteristics to ABS while displaying improved strength and dimensional stability. ASA is best suited and commonly used for automotive, household and research projects that will spend significant time in the outdoors.
What is ASA?
Loading & Unloading Filament *
Bed Surface *
Bed Leveling & Nozzle Height *
Nozzle Temperature *
Bed Temperature *
Removing a print after completion *
Removing Layer Lines
Poor surface quality
Blocked Nozzle / Filament Jam
Stringing / Oozing
Poor Layer Adhesion
Smell during printing
Difficult to remove prints
Purchase or learn about ASA Filaments
What is ASA?
ASA (Acrylonitrile Styrene Acrylate) is an amorphous plastic that exhibits excellent weather resistance and similar characteristics to ABS (Acrylonitrile Butadiene Styrene). The similarities between ABS and ASA are not surprising as these materials share two monomers; acrylonitrile and styrene.
ASA's excellent weather resistance outperforms many other plastics and can be broken down into 3 factors: UV resistance, water resistance and thermal stability.
ASA is stronger and stiffer material than ABS and typically prints with an attractive satin finish. ASA exhibits good chemical resistance and a high temperature resistance, softening at 105˚C (Glass transition temperature).
An enclosed professional 3D printer is highly recommended to print ASA. We recommend only printing with a quality ASA filament.
Minimum Extruder Temperature - 240°C (±10°C) is required (Correct temperature will vary on your printer)
Heated Bed - Required, 80° - 100°C.
Enclosure - Highly recommended for best results.
Heated Chamber - If equipped set between 40° - 60°C.
Part Cooling Fan - OFF or LOW
Feeding / Spooling - No specific requirements.
Other Notes - N/A
Most 3D printing slicers (software) have a pre-configured ABS profile. The accuracy of this profile may vary depending on if you are using 1st or 3rd party filament, but we recommend duplicating your ABS profile to start with and making necessary adjustments covered in this article.
Feeding path and spooling
ASA doesn't have any specific feeding path requirements.
As a general tip we recommend avoiding long and complicated feeding paths that can cause bends in the filament, this can introduce drag on the filament that may result in difficulties feeding and extruding.
If you typically have issues with moisture in your filament, you can read our tips and comments on filament storage to determine if a dry box will be beneficial.
Loading and Unloading Filament *
Changing from a ASA material
If the printer is currently loaded with ASA or a similar material, unload that material at 240-260°C and extrude your ASA filament at the same temperature. Stop extruding the ASA filament after the previous colour is completely purged.
Changing from a higher temperature material:
If the printer is currently loaded with a higher temperature material, unload that material at its recommended printing temperature, and then load and extrude your ASA filament at that same higher temperature. It is important to load the ASA at this higher temperature so the previous material can be pushed out. Stop extruding the ASA filament after the previous material has been completely purged and cleaned out, lower the temperature to 240-260°C, and extrude the ASA plastic for a few more seconds.
Changing from a lower temperature material:
If the printer is currently loaded with a different lower temperature material, unload that material at its recommended printing temperature, and then load and extrude your ASA filament at 240-260°C. Stop extruding the ASA filament after the previous material has been completely purged and cleaned out.
Bed Surface *
Printing with the right bed surface is very important when printing ASA. For ASA we recommend first trying the surface your 3D printer was designed to use. If you have had success 3D printing ABS before then ASA should perform similarly.
|Glass Bed 
Most popular - Straight on glass bed with glue or ABS slurry 
Other options - Buildtak or FlashForge style sheet  | PEI sheet
Most popular - Buildtak or FlashForge style sheet 
Other options - PEI sheet
Most popular -Straight onto perforated board 
Other options - Buildtak or FlashForge style sheet 
|Flex Plate (possibly magnetic)
Most popular - Buildtak or FlashForge style sheet 
Other options - PEI sheet
 - When printing directly to glass we highly recommend removing your models immediately after printing.
 - ABS or ASA slurry is a bed adhesive that is a mixture of acetone and ABS or ASA plastic. To make this yourself we recommend using 50ml of acetone and 5g of ABS or ASA,
 - ASA can stick to printing surfaces and sheets very well, sometimes too well. If models are fusing to the sheets you can increase your nozzle gap or add a layer of glue to act as an interface.
 - This method is generally successful however will rely on compatibility between the ASA and material of the perforated board. With a compatible combination the perforation on the board will grip the model during printing to help prevent lifting or warping. A raft is recommended for the best results.
Bed Leveling & Nozzle Height *
It is important when printing ASA that your first layer adheres to the printing bed.
- Your bed must be properly leveled.
- Your nozzle height must be set correctly. (distance between the nozzle and bed)
The ideal gap between the nozzle and bed is typically a distance of 0.1mm, this is the thickness of two pieces of paper. When changing between bed surfaces it is important to adjust the nozzle height again to compensate for the added thickness of the bed surface.
For optimal results, it is recommended that you pre-heat the buildplate to 80°C at least 10 minutes before 3D printing ASA. Preheating will help to ensure the bed is evenly heated and increase the ambient temperature to minimize risk of warping.
A longer pre-heating time (30 minutes - 2 hours) may be required in cases such as: printing in colder climates, owning a large format 3D printer or owning a printer with a lower wattage heated bed.
If your 3D printer is equipped with a heated chamber, we recommend preheating the heated chamber for 5 to 15 minutes before printing.
Without the right printing environment, ASA will print with too much residual stress which cause parts to warp or crack, compromising the mechanical strength of the part.
An enclosure is highly recommended when 3D printing ASA however users will find they can print some small geometries without an enclosure. Many enclosed printers have top lids / doors which can be opened or removed. When printing ASA on these printers, we recommend closing all doors and lids to maintain a high environmental temperature.
When not in use ASA should be stored away from sunlight and in a resealable bag with desiccant.
Like many other plastics, ASA is a mildly hygroscopic material that will over time absorb moisture from its surrounding environment. This process typically occurs over a period of months however in high humidity environments (ie. evaporative air conditioning) this process can occur more rapidly.
Printing with a dry box is generally not a critical requirement to print ASA (in most cases) however a dry box can be beneficial and ensure consistent printing quality and mechanical results throughout the spool.
Effects of Moisture:
When the filament passes through the hot end the moisture rapidly expands creating bubbles in between layers, poor layer adhesion, inconsistent extrusion due to material expansion and thus poor surface quality.
Preventing Moisture Absorption:
To eliminate all possibilities of moisture impacting your 3D prints, you must store and print your ASA materials in their optimum environment (below 20% humidity) to prevent moisture absorption.
Some users will simply dry their filament before use however excessive drying will degrade the filament. We recommend storing all filaments in a resealable bag with desiccant when not in use and we recommend using a filament dry box like the PolyBox™ when printing. The PolyBox™ is a spool holder / dry box that stores filament in their optimal environment while printing.
If your filament has absorbed moisture it can be dried in a convection oven. Visit our 'starters guide to moisture, drying and filament storage' for recommended drying times.
Nozzle Temperature *
ASA prints at a moderately high temperature, typically printing between 240°C - 260°C.
The optimal printing temperature of an ASA filament will vary depending on which printer you are using and more importantly will vary between filament brands. To find the optimal nozzle temperature we recommend starting with a temperature right in the middle of the manufacturer’s suggested settings. If the manufacturer recommends 240°C - 260°C, printing at 250°C is a good starting point. Based on the quality of the print we suggest adjusting ± 5°C at a time.
Troubleshooting Nozzle Temperature
If the nozzle temperature is too hot, you may experience wisps / stringing on the surface of the print, difficult to remove and fused support material , sagging and poor surface quality on overhangs and a noticeable smell during printing.
If the nozzle temperature isn't hot enough, you may experience compromised mechanical properties due to the poor layer adhesion, under-extrusion (uneven / rough surface quality) and if the filament is not melting fast enough; nozzle blockages.
Bed Temperature *
ASA requires a heated bed set at 80°C -100°C. It is important your heated bed isn’t set above the materials glass transition temperature.
For example the glass transition temperature of PolyLite™ ASA is 97.8°C.
A heated chamber is not required to successfully print parts in ASA however will provide significant benefits when printing large and full-size parts. A controlled actively heated chamber will minimize internal stress (resulting in improved mechanical performance) and ensuring near-zero warping at all sizes.
On printers equipped with an actively heated chamber, we recommend setting the chamber between 40-60°C.
When printing ASA it is recommended to print with the part cooling fan OFF to prevent curling and warping.
LOW fan settings may be applied to improve overhang quality, especially when printing with a heated chamber. The ideal fan setting may be anywhere between 5% - 50%.
A raft is generally not required when printing ASA materials however will be ideal to improve adhesion when printing without a heated chamber or with some printing surfaces.
Additionally with some leveling systems manufacturers may recommend a raft to compensate and improve bed adhesion.
When printing ASA, supports can either be printed in ASA or with a second dedicated support material. Printing with a secondary material will require a printer capable of multi-material / dual extrusion printing.
ASA Supports - Most users own single extruder 3D printers so they print their model and supports in the same material. When printing both the supports and model in ASA, supports will peel away in a similar fashion to ABS.
Soluble Supports - ASA can be printed with a secondary support material that has been engineered to dissolve in a liquid or solvent. Soluble support materials enable users to print complex geometry with superior surface finish on undersides. When printing ASA with multi-material capabilities we recommend using PolyDissolve™ S2.
When using soluble supports we recommend having no gap (z distance) between the model and supports.
Support Troubleshooting - If supports are fusing to the model, try decreasing the printing temperature by -5°C adjustments or increase the distance between the model and supports.
If your supports are failing / collapsing during the print, try increasing support density and printing with a raft, this will improve adhesion for the supports.
Post 3D Printing
Removing a print after completion
Once your 3D print has completed, it can be removed from the build plate. The best method to remove your ASA 3D prints will depend on your build platform with some of these methods specific to removing ASA prints.
Rigid Build Platform
On rigid build platforms like glass or aluminium, a sharp paint scraper can be used to easily remove the model.
When printing on glass, the ASA print must be removed from the glass platform when the temperature is high. Removing a print after the bed has cooled may cause the glass to break as the print can shrink more rapidly than the glass plate.
Some printers are designed so the platform can be removed from the bed while other printers the build platform may be fixed inside the printer. If the platform is fixed, we recommend supporting the platform with your second hand to prevent uneven pressure on the bed which could affect your bed leveling.
Flexible Build Platform
Some printers on the market print on flexible build plates. With these platforms users can flex the plate to remove prints.
Click here if you are having issues removing prints from the build platform.
Removing Layer Lines
With any extrusion based 3D printing process, layer lines are inevitable. For applications requiring the best surface finish, these layer lines can be removed through post-processing. We recommend sanding to eliminate the layer lines from ASA 3D prints however parts can also be post-processed with techniques like acetone vapor smoothing.
We recommend printing your parts with at least 3 perimeters/shells or a minimum wall thickness of 1.2mm if you plan on sanding. This wall thickness will ensure you don’t sand past the external shell and reach the infil.
Wet or dry sanding with a foam block is the most common process to smooth 3D prints. The pressure can be evened through the foam block to create a smoother surface. For the best surface finish we recommend wet sanding. The water will assist to keep the sand paper clean and will dissipate heat from the sanding.
Start with coarse sandpaper and end with high grit sandpaper while always maintaining a circular motion. The ideal grit to choose will depend on what surface quality you require. If you are planning to paint the part, then 240grit sandpaper is sufficient and will also create a nice key for the paint to bond to the ASA. If you do not plan on painting the surface, ASA can be sanded to a very nice matte finish, this will require a higher grit of sandpaper up to 600.
Please wear a face mask when sanding to prevent breathing any dust or particles.
Acetone Vapor Smoothing is an automated post-processing technique that utilizes acetone vapours to melt away the layer lines of ASA 3D prints. There are many variations to this smoothing technique, some of which use heat to expedite the smoothing process. Typically cold vapour smoothing can take between 1-3 hours with careful attention required to prevent over smoothing and achieve an even surface finish.
Safety Warning: Acetone is combustible and flammable so all users interested and investigating acetone vapour smoothing should never heat acetone.
Specific painting recommendations may vary depending on the ASA filament.
ASA plastics can be painted with acrylic and enamel based paints. Removing layer lines and model clean up are recommended before painting.
Unsuitable combinations of solvents in the paint system can attack the material and, depending on the stress condition of the parts, may initiate stress cracking. It is therefore recommended to contact the paint manufacturers who can supply suitable paint systems especially for ASA.
Parts printed in ASA can be joined with a variety of techniques
Gluing parts printed in ASA is simple, with SCIGRIP #16 Fast Set Solvent Acyrlic Cement, Super Glue or Two Part Epoxies. We recommend sanding contact surfaces with a coarse sandpaper to increase the surface area for the glue, this will result in a stronger join.
Solvent Welding with acetone can be applied to join two parts printed in ASA.
- Use a paint brush to coat one contact side in Acetone.
- Carefully join the two parts together.
- Clamp or hold together the join for a few minutes while the contact surfaces fuse together and dry.
Poor surface quality
ASA typically prints with an attractive satin surface finish. Please consider these notes if the surface quality of your models is rough or textured
Improving surface quality.
- We first suggest checking that your spool of ASA is dry. An easy way to test for moisture content in a spool of filament is to extrude the filament, if you hear a distinct popping sound your filament has likely absorbed moisture. As the filament is extruded, the moisture will expand and rupture in the filament creating a rough and inconsistent extrusion. Typically If you experience issues with moisture, printing with a dry box and applying preventative measures will be important to maintain the best printing results.
- If your extruder temperature is too low during printing, the ASA filament won't extrude properly, leaving gaps within the model. Printing with the correct nozzle temperature will solve this issue.
- If your extruder temperature is too high during printing, the filament can sag when printing steep unsupported overhangs. We recommend printing with the cooling fan set to a LOW setting to achieve the best underside surface quality. Printing with a lower nozzle temperature can also improve overhang surface quality.
- If your nozzle is partially blocked the filament will have difficulty extruding. Click here for trouble shooting tips regarding blocked nozzles.
- Slowing down your printing speeds can help to minimize vibration and improve printing.
Blocked Nozzle / Filament Jam
When 3D Printing it is possible to encounter filament jams or nozzle blockages, these blockages can be caused due to a variety of reasons.
Causes and Steps to Prevent Nozzle Blockage and filament jams.
In all of these cases if the filament cannot pass through the extruder, the extruder gear will continue to try push the filament and will eventually 'chew out' the filament. If you hear a clicking or clunking sound coming from the extruder, this is a good sign that the filament is jammed or will be if ignored.
- If your extruder temperature is too low during printing, the ASA filament will not flow and will have difficulty extruding. Printing with the correct nozzle temperature will solve this issue.
- If you are printing with a heated chamber, the chamber temperature may be too high and may be softening the filament near the extruder gear. Try printing with the heated chamber turned off to see if reliability improves, you may find that the chamber temperature should be lower for your 3D printer.
- If there is too much friction on the filament, the extruder may have difficulties feeding the plastic. Try feeding the filament with a spool holder in different positions (above, beside, behind the printer).
- If the nozzle height is set too close to the bed, the filament will have difficulty feeding through the nozzle eventually causing a filament jam. When printing at finer layer heights (0.1 and 0.05mm) the correct nozzle height is even more important. To prevent this issue it is important to print with the bed leveled and the correct nozzle height.
- If the part is warping or lifting off the bed, the part will be pushing against the nozzle limiting extrusion and material flow, in this case it is important to prevent the part from warping.
- Nozzle Blockages can occur more commonly with finer nozzles. The majority of 3D Printers are equipped with 0.4mm nozzles, it is important when printing or experimenting with a smaller nozzle (0.2mm) to adjust printing speed and extrusion settings
- If the filament is of poor quality is oval shaped or manufactured with an inconsistent diameter, this can cause the filament to jam in the extruder. The industry standard for filament tolerance is ± 0.05 mm. If the filament is 1.75mm an acceptable diameter variance would be between 1.70 - 1.80mm. Premium and higher quality brands can offer ± 0.02 mm tolerance. If you have difficulties printing ASA with only specific brands of filament this could signify issue with their quality control or simply printer compatibility.
Cleaning an ASA Nozzle Blockage
If the nozzle is blocked with ASA one of the most successful solutions is to feed a tougher material like PC through the extruder with assistance. As polycarbonate is a considerably tough material, with assistance and a high nozzle temperature you can generally purge and remove the clogged plastic.
Stringing / Oozing
ASA based materials can flow excellently, in some cases leaving behind wisps of plastic during travel movements. If this occurs you can control and minimize this by adjusting settings in your slicing software.
Minimizing and preventing stringing.
- Printing with a cooler nozzle temperature will in many cases help to reduce unwanted oozing as the plastic will flow and solidify at a different rate.
- By increasing the retraction length or retraction speed in your slicer settings, the extruder will withdraw a short distance filament from the nozzle, helping to prevent oozing when the extruder travels between points.
- If the spool has absorbed moisture, the moisture will affect the flow rate and viscosity of the material causing unwanted stringing and wisps.
- When printing with a heated chamber, if the temperature is set too high you may notice more oozing and stringing. If the oozing is a result of the heated chamber you can experiment with lower chamber temperatures to control the flow behavior.
When printing higher temperature amorphous materials like ASA, some users can have difficulty preventing warping, firstly lets look at why ASA materials can warp.
Warping is caused by internal stress in the 3D printed part; there is one cause for internal stress when printing amorphous materials.
1. As the filament is extruded through the small diameter of the nozzle, the polymer chain of the filament is stretched and will want to return back to its ‘normal’ state, much like a stretched elastic band will go back to its position when it is released. If the ASA is printed in a heated environment, the polymer chain will 'relax', releasing the internal stress and preventing the part from warping. If the material is printed without a heated environment the material will print with residual stress. As more plastic is deposited during large prints the residual stress will eventually overcome the bed or inter-layer adhesion and cause cracking or warping.
So how can we prevent warping and achieve near-zero warping when printing ASA.
Preventing ASA warping.
- If parts are warping early into the print, this may be due to insufficient bed adhesion or an incorrect nozzle height. If the first layer of extruded plastic is not sticking to the bed, the internal stress during printing will be enough to quickly lift the part off the bed. It is important to ensure your nozzle height and bed is leveled correctly and that you are using the correct printing surfaces for ASA.
- Printing on a printer equipped with an actively heated chamber is one solution to printing ASA with near-zero warping. A heated chamber is important to successfully print large full-size parts in ASA (eg. 300 x 300 x 300mm).
- Drafts, cool air from air conditioners and low environmental temperatures in winter can cause the ASA to print with more internal stress. An enclosure with a closed front door can help to contain heat from the heated bed, raising the internal temperature required to minimize warping.
- In an enclosed build volume of 150 x 150 x 150mm, heat from the build plate will raise the internal chamber more efficiently and faster than with a larger 250 x 250 x 250mm build volume. Preheating for a longer time may be required on larger printers to reach the required internal temperatures.
- Printing with a lower infil will produce parts with less material and thus less internal stress, this can effectively minimize warping in some case. Parts printed at 100% will suffer from significant warping when compared to parts printed at 25-50%. Parts should still be printed with a moderate infil (above 20%) as parts printed with a low infil will have less surface area across layers and become more susceptible to cracking.
- Typically warping will occur on the outer edges of a 3D Print. In some cases, a raft can be used to extend the length of the part. The outer edges of the raft will warp instead of the part.
Cracking between layers
Materials like ASA require the right environmental temperature for the best results. When the environment is not controlled and consistent, residual stress will build up during the printing process and will release through the form of cracking or warping.
- The best solution is to print ASA without any internal stress; this can be achieved when printing with a heated chamber and will result in practically no risk of cracking or warp.
- If you don't have access to a heated chamber we recommend ensuring your 3D printer is enclosed and that you are printing with the highest recommended nozzle temperature. The passive heat from the heated bed will be contained in the enclosure and the nozzle temperature will maximize inter-layer bonding.
- Printing with more perimeters can increase the surface area between layers, improving the bond and reducing the risk of cracking.
Poor layer adhesion
Causes and steps to improve poor layer adhesion.
- If the filament is under-extruding during printing there will be inconsistencies and gaps between the layer, compromising mechanical strength and layer adhesion. It is important to ensure you are printing the ASA filament at the right nozzle temperature to ensure consistent flow and to minimize drag or tension which may prevent the filament from feeding.
- Printing with the cooling fan ON can negatively impact inter-layer adhesion. Printing with a LOW setting can be beneficial when printing overhangs in ASA but for the purposes of improving inter-layer adhesion, first experiment with the cooling fan turned OFF to see if your adhesion improves.
- If your model is printed with a lot of internal stress, the inter-layer performance of your model will be compromised. We recommend following our tips in relation to cracking.
- Poor layer adhesion can also be caused when printing with ASA that has been spoiled with moisture. When the filament passes through the hot end, the moisture erupts creating bubbles in the extruded plastic, compromising the parts mechanical properties. If a spool of filament has absorbed moisture, it can be dried however it is important to store the ASA correctly and prevent this issue from occurring.
Smell during printing
Compared to other 3D printing materials, ASA can sometimes print with a noticeable smell.
Causes and steps to minimize printing odors
- ASA materials will release a noticeable smell during printing if printed too hot. Printing at lower nozzle temperatures can sometimes minimize noticeable odors when printing ASA.
- Placing the printer in a ventilated space can help to minimize odors when printing ASA, odors will also be less noticeable when printing with enclosed printers.
- Some 3D printers are equipped with HEPA / carbon filters which can help to minimize the smell when printing ASA plastics.
Parts difficult to remove from platform
To print a successful print excellent adhesion between your first layer and the the bed is critical, but in some cases it can be difficult to remove models if your adhesion is too good.
Causes and steps to improve print removal experience
- Some print surfaces specifically manufactured for ASA materials are designed to maintain adhesion with the part when the bed is heated and self-release when the part is cool. Try removing the models when the heated bed is hot or cold to see what method best suits your printing surface.
If you are printing on glass however, please always remove the part when the glass bed is HOT.
- Your heated bed may be operating too hot or your nozzle temperature may be too close to the bed. You can try making slight adjustments to the heated bed temperature or nozzle height if this improves your user experience. Of course this is a fine balance as adhesion between the print and platform is important to achieve successful prints.
- Some users will use glue stick on top of their print surface to act as a release agent for part removal.
ASA Filament Introduction
Buy ASA Filaments
PolyLite™ ASA Introduction
Buy PolyLite™ ASA