PETG (Polyethylene terephthalate glycol-modified) and PLA (polylactic acid) are both commonly used and readily available thermoplastic materials for FDM 3D printing. This means they will soften when heated and then solidify when cooled, making them well-suited for 3D printing. These materials are heated at the hotend, pushed out by the extruder, and then cooled into the required shape by the cold end.
PETG is a 3D printer filament that makes a great balance between PLA and ABS. It is more resilient than PLA and easier to print than ABS. This article is a comprehensive guide for the comparison between PETG and PLA, covering aspects such as printability, mechanical properties, applications, ease of post-processing, cost and price.
- Ease of Printing
- Mechanical Properties
- Pros and Cons
PETG vs PLA: Ease of Printing
(Anycubic Kobra 2 Pro is capable of printing with PETG.)
3D Printing with PETG filament can be more challenging than PLA, as PETG requires higher printing temperatures and slower print speeds. PLA has a lower melting point, typically requiring nozzle temperatures of 190-220°C and bed temperatures of 50-70°C, making it compatible with nearly all 3D printers. This makes it very easy to print with, ensuring stable performance, and minimal warping when building printed parts.
However, PETG 3D printer filament has a higher melting point, with its optimal printing temperature range being 220 to 250°C, and it requires a heated bed at 70°C to 80°C. Not all printers are capable of reaching such high temperatures, but Anycubic's Kobra 2 Pro performs well in printing PETG filament. To avoid constant testing for the optimal printing settings, Anycubic provides profiles for different materials for their machines, which can be easily imported into slicing software like Cura or PrusaSlicer. Additionally, PETG needs to be printed at a slower speed than PLA, especially in bridges and overhangs, because it is more sticky, which can easily result in stringing.
PETG vs PLA: Mechanical Properties
(PETG is suitable for making mechanical and functional parts.)
In terms of mechanical properties, the most noticeable difference between PETG and PLA emerge. We will compare them based on flexibility, impact resistance, hardness, weather resistance, and durability.
PETG 3D printer filament has better flexibility and impact resistance compared to PLA. PLA is a relatively rigid material, making it more prone to becoming brittle and breaking under pressure impact. In contrast, although PETG is not as hard as PLA, it performs better flexibility to withstand bending and strength. In other words, if subjected to a sudden impact force, PLA can withstand greater stress, but once it exceeds its threshold, it may break into pieces. These pieces pose a potential danger. On the other hand, PETG is more flexible, less brittle, and will bend before fully breaking.
PETG not only has better impact resistance but also shows good weather resistance and durability. Due to its higher melting point, PETG performs well in heat resistance. In addition, PETG is water-, chemically-, and UV ray-resistant. This means that PETG is a kind of more durable plastic for outdoor use compared to PLA. For example, in hot and sunny weather or on rainy days with high humidity, parts printed with PLA are more likely to soften and deform compared to those made with PETG.
PETG vs PLA: Applications
(Printed with Anycubic 1.75mm PETG 3D printer filament.)
PLA 3D printing filament is ideal for creating visual prototypes and meeting daily creative needs. A variety of colors for PLA are easily accessible in the market, greatly unleashing your imagination. The ease of use and simpler post-processing features of PLA enable you to finish your 3D printer projects more efficiently. However, for outdoor purposes, PETG's high toughness and weather resistance make it more suitable for printing mechanical parts compared to PLA. Additionally, PETG has higher transparency than PLA, resulting in it suitable for projects requiring a transparent effect, such as lampshades, vases, and other artworks that require light transmission.
Both PETG and PLA are generally considered food-safe, but it cannot be guaranteed that the materials remain uncontaminated during the heating and printing process. Therefore, it will be best to avoid direct contact between printed parts and food, as it is not 100% safe.
PETG vs PLA: Post-processing
PLA for 3D printing is easier to post-process than PETG filament, including support removal, sanding, priming, and painting. PETG exhibits excellent layer adhesion, meaning that layers adhere well to each other during 3D printing, reducing issues like layer separation. However, this sticky characteristic also poses challenges in post-processing for PETG. Care must be taken when removing PETG supports, as it can easily leave noticeable support marks. Therefore, it is more difficult to sand your PETG parts to eliminate surface imperfections, such as zits, roughness, and Z-seams, for a smoother finish.
Applying a primer is crucial for PETG because the paint is hard to stick to its surface, ensuring good color coverage. In contrast, PLA is much easier to handle during post-processing. When deciding between PLA and PETG for your project, it's essential to consider the differences in their ease of post-processing.
PETG vs PLA: Storage
PETG 3D material is more hygroscopic than PLA, meaning it absorbs moisture more readily. Therefore, for filament storage, PETG needs better protection. Vacuum storage bags or boxes are excellent tools to keep the material dry. If, unfortunately, your material absorbs moisture and becomes damp, you must dry it before printing. Wet filament tends to string on the part during printing, reducing print accuracy and even leading to printing failures. Ovens, food dehydrators, and filament dryers can be used to dry your materials, but different materials require different drying times and temperatures. I recommend checking this guide on 'How to Dry Wet Filament' for more information.
PETG vs PLA: Costs
Generally speaking, PETG tends to outperform PLA according to performance, and its price is usually higher than that of PLA, which is understandable. For example, Anycubic's PETG is priced slightly higher than PLA. Anycubic is a 3D printer manufacturer and also provides 3D materials. The price of their PETG is a bit higher than PLA, with PETG priced at $26 per kg compared to PLA at $24.50 per kg. However, Anycubic has a competitive advantage in pricing and often offers material sales, such as "Get 3 for the price of 2" and bundle sales, sometimes even as low as $11.99 per kg.
Where to buy quality PLA & PETG filaments?
Video for Anycubic PETG 1.75mm 3D printer filament
Video for Anycubic PLA 1.75mm 3D printer filament
Which Is Better: PLA or PETG?
It's difficult to definitively say whether PLA or PETG is better; both are excellent choices for FDM printing, and the answer depends on your project requirements and your 3D printing skills. Printing with PLA is the safer option if you are a beginner. PLA's ease of use and stable printing performance make it easy to achieve high-quality prints. Once you've mastered some 3D printing techniques, you can then explore PETG materials. If you need to print mechanical parts such as clips, clamps, holders, or planters, PETG is better than PLA due to its excellent layer adhesion, providing outstanding resistance to force and water. Additionally, PETG is typically more expensive than PLA, so if your budget for a large project is limited, PLA is the better choice to save your money.
Recap the comparison between PLA and PETG:
Q: Is PETG better than PLA?
A: The mechanical properties of PETG are better than PLA, offering good impact resistance and weather resistance. However, PLA is easier to use and more affordable than PETG.
Q: Is PLA or PETG better for UV resistance?
A: Yes, PETG is more UV resistant and durable, making it suitable for mechanical outdoor use.
Q: Is PETG as safe as PLA?
Q: What are the disadvantages of PETG?
A: PETG is more challenging to use and post-process compared to PLA, and the cost is typically slightly higher than PLA.