When choosing the best filament for 3D printing, PLA (Polylactic Acid) and PETG (Polyethylene Terephthalate Glycol) are two of the most commonly used options. Both materials have specific qualities that make them popular among 3D printing enthusiasts and professionals alike. In this article, we’ll compare PETG vs PLA in terms of printability, strength, durability, heat resistance, environmental impact, and cost. By the end, you’ll have a clearer understanding of which filament is best suited for your 3D printing needs.
Key Differences Between PLA and PETG
Understanding the key differences between PLA and PETG will help you decide which material is the best fit for your projects.
| Property | PLA | PETG |
|---|---|---|
| Ease of Use | Extremely easy to use; ideal for beginners | More difficult to use; requires precise temperature control |
| Printing Temperature | 180°C – 220°C | 220°C – 250°C |
| Heat Resistance | Low (up to 60°C) | Higher (up to 80°C) |
| Strength | Brittle, more prone to breaking | Strong, flexible, impact-resistant |
| Chemical Resistance | Low | High |
| Surface Finish | Glossy and smooth | Glossy or matte, depending on settings |
| Environmental Impact | Biodegradable, but needs industrial composting | Recyclable, but not biodegradable |
| Best Applications | Decorative prints, small models | Functional parts, tools, outdoor applications |
1. Strength and Durability Comparison
When it comes to the strength and durability of 3D prints, PETG has a significant advantage over PLA. While PLA is relatively strong when first printed, it tends to become brittle over time, especially when exposed to mechanical stress or environmental conditions. On the other hand, PETG has much higher tensile strength, which makes it better suited for functional parts that need to withstand impact and pressure.
Strength and Durability Test:
| Filament | Tensile Strength (MPa) | Impact Resistance | Durability |
|---|---|---|---|
| PLA | 37 – 55 | Low | Low |
| PETG | 50 – 70 | High | High |
As shown in the table above, PETG performs better in both tensile strength and impact resistance, making it the preferred choice for parts that need to endure more demanding conditions. PLA, while excellent for aesthetic prints and prototypes, will break under pressure or stress, making it unsuitable for parts like mechanical components or functional tools.
2. Heat Resistance Comparison
PLA has relatively low heat resistance and will start to deform at temperatures as low as 60°C, which makes it unsuitable for applications exposed to high temperatures or heat sources. PETG, however, has a higher glass transition temperature (around 80°C), allowing it to retain its shape and strength in hotter environments. This makes PETG the better choice for parts that need to endure heat or outdoor exposure.
| Filament | Glass Transition Temperature | Heat Resistance |
|---|---|---|
| PLA | 60°C | Low |
| PETG | 80°C | High |
Whether you’re printing parts for cars, tools that will be exposed to the sun, or mechanical components that need to endure heat, PETG will be the better option due to its superior heat resistance.
3. Environmental Impact Comparison
When it comes to sustainability and eco-friendliness, PLA stands out as the more environmentally friendly option. Made from renewable resources like cornstarch and sugarcane, PLA is biodegradable under industrial composting conditions. However, it does not break down in typical landfill conditions, and its environmental impact is still a subject of discussion in the 3D printing community.
PETG, on the other hand, is not biodegradable but is fully recyclable. It’s derived from petroleum-based sources, which makes it less eco-friendly than PLA. However, its ability to be recycled gives it a more sustainable edge in comparison to other plastics.
| Filament | Biodegradable | Recyclable | Environmental Impact |
|---|---|---|---|
| PLA | Yes, under composting conditions | No | Biodegradable but not suitable for landfills |
| PETG | No | Yes | Recyclable but not biodegradable |
For those looking to reduce their environmental impact, PLA is the better choice for aesthetic models, as it can be composted under industrial conditions. However, for users prioritizing recyclability and higher durability, PETG might be more practical despite its less favorable environmental profile.
Which Filament is Better for Specific Applications?
The choice between PLA and PETG largely depends on the type of project you’re working on. Below is a comparison of how each filament performs in different applications.
| Application | Best Filament | Why |
|---|---|---|
| Aesthetic Prints (Models, Figures, Decorative Items) | PLA | Easy to print, smooth finish, low heat sensitivity |
| Functional Parts (Tools, Brackets, Gears) | PETG | Strong, impact-resistant, flexible, heat-resistant |
| Outdoor Parts (Drones, Garden Tools) | PETG | Better UV and heat resistance, durable under outdoor conditions |
| Prototypes (Low Stress Models) | PLA | Fast, affordable, biodegradable |
| Parts Exposed to Chemicals (Pipes, Tanks) | PETG | Excellent chemical resistance, ideal for functional and industrial parts |
For functional parts that need to withstand stress, PETG is the go-to filament. It’s ideal for gears, tools, and other parts exposed to mechanical or environmental stress. Meanwhile, PLA remains the top choice for decorative prints that don’t require durability or exposure to heat.
Printability Comparison: PETG vs PLA
When it comes to printability, PLA is hands down the easier filament to work with. It has a lower printing temperature, typically between 180°C and 220°C, and can be printed on most 3D printers without any specialized equipment. Additionally, PLA is less prone to warping and does not require a heated bed in most cases.
PETG, while not difficult to print with, does require more attention. The higher printing temperature of 220°C to 250°C means that it may not work well with entry-level 3D printers that cannot reach these temperatures. PETG is also more prone to stringing and requires fine-tuning of retraction settings.
| Property | PLA | PETG |
|---|---|---|
| Print Temperature | 180°C – 220°C | 220°C – 250°C |
| Heated Bed | Optional | Required for optimal results |
| Warping Tendency | Low | Moderate |
| Printer Compatibility | Works well with most printers | Works well with higher-end printers |
| Stringing | Minimal | Moderate (requires tuning) |
While PLA is more beginner-friendly, PETG can be mastered with a bit more experience. With the right settings, PETG can produce high-quality prints that are far more durable than PLA prints.
Conclusion: Which Filament Is Better for You?
When choosing between PETG vs PLA, it’s essential to consider the specific requirements of your project. Here’s a quick recap of when each filament shines:
- Choose PLA if:
- You’re a beginner or new to 3D printing.
- You need to create aesthetic models or decorative prints.
- You’re looking for an environmentally friendly option.
- Heat resistance isn’t a concern for your application.
- Choose PETG if:
- You need durability and strength for functional prints.
- Your prints will be exposed to higher temperatures or UV light.
- You require chemical resistance or outdoor durability.
- You’re printing parts that need to be flexible and impact-resistant.
Ultimately, both PLA and PETG have their advantages and applications, and your choice should align with the specific needs of your project. Understanding the strengths of each filament will allow you to make an informed decision for your next 3D printing venture.