You may be familiar with the strongest 3D printing filament, the most flexible, or the most durable, but what materials are best for your outdoor parts or products? Is UV resistance all you need to consider? Turns out that there are several plastic properties that contribute to long-lasting outdoor applications, including moisture and temperature resistance, plus color stability.
The outdoor products you may already have, such as furniture, garden equipment, and toys, are typically made from polyethylene (PE). Unfortunately, PE is not available for 3D printing since it has such a low melting point (much lower than PLA) and poor layer adhesion. This leaves you needing an alternative.
Whether it’s for functional parts or decorative pieces, selecting the right material can make all the difference in resistance to environmental factors like sun, heat, cold, chemicals, and moisture over time. Let’s explore some of the best 3D printing polymer materials tailored for outdoor applications and the attributes that help them withstand the weather.
But first, it’s handy to understand how outdoor elements affect polymers.
UV light is the most damaging environmental factor for plastics. Ultraviolet radiation from the sun breaks down the chemical bonds in a polymer by a process called photodegradation, which not only causes a change in appearance, such as yellowing or whitening (“chalking”), but also deteriorates the physical properties. The second most damaging element to plastic is moisture. We often think of plastics as waterproof, but different polymers actually absorb water at different rates, leading to swelling that can be hard to notice, but is no less damaging to the strength and function of your outdoor part over time.
Heat and cold are also important factors to consider. Although most plastics will not melt in even the hottest outdoor environments, they can soften enough to fail mechanically, which is a problem for any functional part like a bracket, clasp, or enclosure. Another question to consider is whether your part will come in contact with any chemicals, solvents, oils, or the like, such as pool chemicals, bike grease, or even a lot of pollution.
Since there is no one 3D printing polymer material with excellent UV, chemical, heat, and moisture resistance, you’ll need to pick the one that has the specific strengths to fit your application.
PETG (Polyethylene Terephthalate Glycol)
PETG is a popular choice for outdoor 3D printing due to its excellent strength, impact resistance, and weatherability. It boasts fair UV resistance, making it less prone to yellowing or degradation when exposed to sunlight over time, but not as resistant as another clear material, PC.
PETG offers good chemical resistance, making it suitable for outdoor environments where exposure to various elements is common. Yet, as a thermoplastic polyester, as opposed to a thermoset plastic, it can be deformed with high heat, so should be kept out of direct direct all-day sunlight to avoid warping.
There are special versions of PETG with added UV resistance, such as the Eolas Prints PETG UV resistant filament that has been altered to make it more UV resistant promising that the color will remain intact for a minimum of five years. The trade off is that this version of PETG is not food-safe. You can also boost the strength of your UV-resistant PETG with another variation, glass-fiber reinforced PETG GF UV from companies like Nanovia.
ASA (Acrylonitrile Styrene Acrylate)
ASA is specifically engineered to withstand harsh outdoor conditions, making it an ideal choice for 3D printing outdoor products and parts that won’t lose their mechanical properties or color. It exhibits high UV resistance, ensuring long-term color stability and preventing deterioration from prolonged exposure to sunlight.
ASA also maintains its mechanical properties across a wide temperature range, further enhancing its suitability for products that you’ll have outdoors year-round that may freeze in winter and swelter in summer. ASA exhibits good resistance to chemicals, oils, and solvents, making it suitable for applications where exposure to various substances is expected.
Also, consider ASA blends that offer higher mechanical properties, such as ASA/PC and ASA/PVC.
My Verdict
Although ASA was created for outdoor use and has strong mechanical properties, the only reason it is not our top pick is that ASA emits potentially harmful fumes while printing and requires a 3D printer with a nozzle temperature that can reach about 230ºC. If you’re ordering a part from a print service, however, ASA would be our tip choice for all types of outdoor parts.
Nylon with UV stabilizers
Nylon (PA 12 and the more environmentally friendly PA11) is renowned for strength, toughness, and flexibility, making it a versatile material for outdoor applications. It offers excellent impact resistance and can withstand bending and flexing without cracking or breaking, making it suitable for functional parts subjected to varying loads. Nylon has good chemical resistance, yet it does absorb moisture.
PA11 is less susceptible to UV rays than PA12 and is often used in outdoor applications where prolonged exposure to sunlight is expected, such as automotive components, outdoor equipment, and architectural fixtures. It is also known for its resistance to many common chemicals, including oils, greases, fuels, solvents, and alkaline solutions.
If you’re looking for the properties of PA11 made specifically for outdoor use, look for a UV stabilized polyamide 11, which includes additives.
UV stabilizers are additives mixed into the nylon polymer during filament production. Their job is to absorb or block UV radiation, preventing it from breaking down the polymer chains that cause brittleness, color fading, and loss of mechanical properties.
UV absorbers, such as benzotriazoles, absorb harmful UV rays before they can degrade or discolor the nylon.
Even with UV stabilization, coating your nylon prints with a UV-resistant clear spray can extend their lifespan dramatically.
My Verdict
If strength and durability of your outdoor functional parts is the primary concern, there’s nothing better than PA11, especially a carbon-fiber or glass-fiber reinforced version. This material is our top pick for outdoor sporting goods and parts that have a function, like a latch. It’s also ideal for parts that may encounter come chemicals, like motor exhaust.
Choosing the right 3D printing filament for outdoor use isn’t just about picking one that resists UV light — it’s about balancing multiple environmental factors including heat, cold, moisture, and chemical exposure. While PETG is a great all-rounder for weather-resistant prints, ASA is hard to beat for color stability and UV protection in aesthetic parts, especially if you’re using a print service. For serious strength and long-term durability, especially under mechanical stress or chemical exposure, UV-stabilized PA11 stands out as the premium choice.
Ultimately, the best material depends on your specific application. Whether you’re printing decorative garden features, functional brackets, or high-performance outdoor gear, knowing how each material behaves under the elements will help ensure your parts not only look good but last for years to come.
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