Filament selection is one of the most vital steps for a successful project, as it essentially defines the majority of the properties your 3D printed model will have that you won’t be able to modify later on.
With many filaments to pick from, and with each filament having a different set of attributes in terms of factors such as strength, durability, printing requirements, and more, it’s vital to be familiar with all the properties for a successful project.
Due to the gaining popularity of PETG filament as the choice for most 3D printing enthusiasts lately, we decided to write today’s article on a specific property of PETG that doesn’t get mentioned often, which is UV (ultraviolet) resistance.
So, is PETG UV resistant?
PETG is one of the most UV-resistant filament types available. While minor UV-related damage such as color degradation can occur over long periods, the mechanical properties of PETG won’t be affected by ultraviolet rays even after years of exposure.
In the upcoming sections, we will take a more detailed look at the UV-resistance capability of PETG, compare PETG to other popular filaments in terms of UV resistance, and discuss how suitable PETG is for outside usage.
Is PETG UV Resistant?
While UV resistance isn’t a topic that comes up often, it’s a vital factor to keep in mind for projects that will be exposed to UV rays for extended periods, as UV rays can as effortlessly cause damage as factors such as heat or water.
Among the most-used filament types in 3D printing, PETG takes the top spot for UV resistance as it does not degrade and deform due to ultraviolet rays, even after constant exposure for years.
While unlikely, the maximum damage that UV rays can do to PETG is the degradation or fading of color, which shouldn’t be a cause of concern considering that it would take an extremely long amount of time anyway.
Considering that PETG is also one of the most undemanding filament types to print due to it not requiring any extra equipment such as an enclosure, it’s a fantastic option for any project where UV resistance is a concern.
Can PETG Be Used Outside?
Considering that the sun is the primary source of UV rays, the suitability of using PETG outside is one of the first things that come to mind, where it’s most likely to be exposed to UV rays.
Since neither UV rays nor environmental factors such as wind or rain won’t have an effect on the structural integrity of a model printed with PETG, you can freely use PETG for outdoor applications without concern.
As PETG is a material primarily known for its water resistance, fatigue resistance, and durability properties, it checks all the boxes for surviving outside conditions, making it one of the best choices for projects that will stay outside for prolonged periods.
Please note that while discoloration or fading of the color can eventually occur due to exposure to sunlight for long periods, it’s not a sign that the PETG is degrading structurally.
Can You Leave PETG in the Sun?
When it comes to intentionally leaving PETG out in the sun, the primary cause of concern becomes heat rather than the UV rays that don’t have much of an effect.
With a glass transition temperature (the point where the plastic will start deforming) of 80 to 85 degrees Celsius on average, we can consider PETG to be reliably heat resistant.
While possible in theory, it’s quite unlikely for any environment to reach the temperatures PETG will deform at just by exposure to sunlight, meaning that leaving PETG in the sun shouldn’t be a cause for concern in most scenarios.
To stay on the safe side, we recommend measuring the environment’s temperature before placing your model in it, especially in cases where a closed environment can get a lot of sunlight (such as a car) for extended periods.
PETG vs. PLA UV Resistance & Outdoor Usage
There is no denying that PLA is the most popular filament on the market right now, which makes it natural to wonder how well it does against UV rays compared to PETG.
Compared to PETG, PLA is much weaker in terms of UV resistance, water resistance, heat resistance, and fatigue resistance, making it unsuitable for outdoor usage, regardless of UV exposure.
We can only recommend using PLA indoors, as almost any environmental factor can quickly damage models printed with PLA and cause them to deform.
PETG vs. ABS UV Resistance & Outdoor Usage
While not as popular as PETG, ABS is another commonly-used filament type in the 3D printing world.
While ABS is resistant to UV rays to some degree, it can lose its structural integrity due to UV exposure, unlike PETG, making PETG the better choice in terms of UV resistance.
Since ABS is as water and fatigue resistant as PETG; and even more heat resistant than PETG, it’s still a suitable option for outdoors projects where exposure to sunlight isn’t too severe.
As ABS is more difficult to print than PETG, PETG is usually the go-to choice in most scenarios.
PETG vs. ASA UV Resistance & Outdoor Usage
ASA isn’t a filament type that we hear about as often compared to materials such as PETG, PLA, and ABS, but it’s known to do a fantastic job in the UV resistance department.
Since ASA is as UV, water, and fatigue resistant as PETG; and even more heat resistant than PETG, it’s an even better option than PETG for outdoors projects.
On the other hand, ASA is more challenging to print compared to PETG, meaning that PETG will do the job just fine unless you need the increased heat resistance that comes with ASA.
PETG is definitely one of the better filament types in the UV resistance department, making it suitable for outdoor usage where the model will stay in sunlight for prolonged periods.
To summarize, PETG is one of the best materials for UV resistance as UV rays can never impact the structural integrity of PETG and cause it to deform, no matter the severity or the length of the exposure.
While discoloration can occur in some cases after prolonged exposure to UV rays, it’s nothing more than a visual change that won’t affect the durability of your model.
Combined with the fact that PETG is relatively undemanding to print and highly resistant to most natural environmental conditions such as water, wind, heat, and UV rays, it’s definitely one of the go-to choices for most outdoor projects.