Material warping, layer adhesion and material choice are some of the biggest headaches in 3D printing. This is something that startups and mid-sized firms really wrestle with, and it has a big impact on product quality and production costs.Material selection can affect print velocity, sturdiness, and eco-friendliness.
PETG vs PLA: what you need to know to optimize your 3D printing. We will discuss how to solve these challenges and share our insights in PETG and PLA.
The Core PETG vs PLA Filaments
The fundamental differences between PETG and PLA filaments lie in their composition and properties, which significantly impact their performance in 3D printing applications. PETG filament gives you stronger, more flexible, more durable 3D prints than PLA — perfect for functional parts that must resist impact and stress.
PLA, on the other hand, has a shrinkage rate of about 0.3%, while PETG falls somewhere in between, shrinking approximately 0.3 – 0.8%.
1. Mechanical Strength
Comparing the tensile strength & durability of PETG and PLA filaments, PLA usually has a higher tensile strength than PETG, with values of approximately 50-60 MPa as opposed to PETG’s 40-50 MPa. PETG’s impact resistance is medium and PLA has low impact resistance, which impacts their appropriateness based on use and end-use needs.
There are important overlooked variables that influence 3D printed objects’ strength — layer adhesion, infill density — that should be considered to optimize print settings and post processing.
2. Temperature Tolerance
The heat resistance of PETG and PLA filaments is another critical factor. PETG has a glass transition temperature of 75 to 85 °C, which is remarkably higher than PLA’s. The melting points and glass transition temperatures of PETG and PLA respectively need to be analyzed to confirm the thermal stability of the printed pieces.
With correct printing and post-processing, you’ll encounter no warping or dimensional instability.
3. Printability
Printability of PETG and PLA filaments are important questions to ask. PETG necessitates elevated printing temperatures, generally ranging from 220°C to 260°C, and a heated bed configured to 70°C–90°C, while PLA is capable of being printed at comparatively reduced temperatures.
PETG and PLA filaments’ flow characteristics and layer adhesion are also crucial. Well-calibrated printers are all you need to fix typical PETG and PLA printing problems like warping and delamination.
4. Visual Finish
When considering PETG vs PLA, the surface finish and appearance of prints are significant factors. PLA is commonly chosen for decorative models and prototyping given its printability, low warping, and cost-effectiveness.
Instead, PETG is selected for its strength, flexibility, and durability. Both PETG and PLA prints can be post-processed, such as sanding and painting to improve their texture and color.
5. Material Cost
Comparing the cost of PETG and PLA filaments is essential in determining their suitability for various applications. The cost-effectiveness of PETG vs PLA for different 3D printing applications should be evaluated.
Recycled materials and optimized print settings can go a long way towards minimizing the cost of PETG and PLA printing.
Navigating the Printing Process
Proper printer setup and calibration are essential for successful PETG and PLA printing as they affect the quality and precision of the end result. Calibration is critical because it guarantees that your printer’s mechanics are in order and that the printing parameters are optimized for your particular filament.
That’s tuning your printer’s temperature, bed leveling and extruder calibration to find that sweet spot for PETG or PLA printing. Additionally, a well-calibrated printer can avoid issues like warping, stringing and layer shifting which are a pain to debug.
The PLA Experience
Print PLA is a little tricky, especially when it comes to temperature and speed. Best print temps for PLA are generally 180-220C with a heat bed of 50-60C. They need to hit the magic balance between temperature and speed to get a nice, even print.
While PLA printing is less prone to warping and stringing, they can still occur with PLA, which can be mitigated by using a heated chamber or tweaking retraction settings. Sanding and gluing are typical post-processing methods to improve PLA prints.
PLA is a well-liked option among 3D filaments because of its user-friendliness and adaptability. It’s brittle and cracking. Despite these drawbacks, PLA continues to be a favored option for various purposes such as prototyping, model creation, and student projects.
With PLA, you have to think about the print surface and may want to employ sanding or smoothing techniques.
The PETG Challenge
PETG is a tricky material to print with, especially when it comes to adhesion issues and layer shifting. To combat these issues, you need to employ a nozzle size of ≥ 0.15mm and optimal printing temperatures of 220-250°C, with a heat bed temperature optimally set at 80-90°C.
PETG printing needs more heat than PLA, which can aid in stronger layer adhesion. This elevated temperature can further contribute to warping and layer shifting.
Some common printing modes and techniques used for PETG and PLA include:
- Fused Deposition Modeling (FDM)
- Stereolithography (SLA)
- Selective Laser Sintering (SLS)
- Layer shifting and warping prevention techniques
- Support material generation and removal
PETG is a more flexible and durable material than PLA, so it’s great for applications that need strength and impact resistance. Its pliability means that it can be more difficult to post-process, especially sanding/painting.
In most cases, you’ll want to first sand or otherwise smooth the surface before painting on either PLA or PETG to get the best results. Thinner layers tend to make stronger parts because they adhere better to each, but take more time to print.
When to Use PLA
PLA is the favorite for high-precision prints like prototypes and decorative objects. The benefits of PLA for these applications is that it’s easy to print, biodegradable, and has a low carbon footprint. PLA’s low shrinkage rate and minimal warping makes it an excellent candidate for high-precision prints.
PLA has several limitations, including:
Not very chemically resistant, so not appropriate to use with acids, bases, alcohols and fuels.
Not very impact-resistant – it cracks and breaks easily.
Not thermally stable, so not good for high temperature applications.
Not for the outdoors, as it can rot fast in the sun and rain.
To post-process PLA prints, sanding, painting, or applying a coat of varnish to protect the print from moisture and UV light are widely used. PLA’s biodegradability and low carbon footprint make it the favored choice for applications in which environmental sustainability is a factor.
When to Use PETG
PETG is the go-to for functional prototypes and end-use parts, including robot and machine parts and tooling. The advantages of using PETG for these applications include:
High impact resistance and durability so you can print functional parts that will endure daily wear.
Chemical resistance for acid, base, alcohol and fuel handling.
Thermal stability, for high temperature applications.
Food-safe, which has made it popular in the food world.
PETG is limited in that it’s more expensive than PLA and a little more difficult to print. PETG’s 75-85°C glass transition temperature makes it heat-resistant enough for many applications.
Beyond Basic Strength
The PETG vs. PLA filament comparison title is beyond basic strength in that both are exploring impact resistance, flexibility and other mechanical properties. For instance, PETG has a heat deflection temperature of approximately 70°C. It is this property that makes PETG a good candidate for heat-related applications. A few users say PETG is harder to print with at first, but once dialed in it offers good thermal resistance beyond basic strength.
Impact Resistance
That’s why it’s important to examine the impact resistance of PETG and PLA filaments, which contributes to their toughness and resilience. While PETG’s impact resistance rates higher than PLA’s, making it a superior pick for needs involving shock absorption and stress.
PETG’s molecular structure and crystallinity impact resistance as compared to that of PLA’s, with PETG’s more linear molecular structure making it more impact-resistant. PETG is more flexible because it can bend and flex without fracturing. Its impact strength is influenced by the molecular weight, crystallinity and additives of PETG and PLA.
For instance, carbon fiber reinforced PETG is even tougher, albeit more expensive. By comparison, engineering resins – which beat out both PETG and PLA in terms of relative strength – can handle temperatures in excess of 200°C. If you want to make your PETG and PLA prints more impact resistant, though, proper printing settings and post-processing are key. This means tuning the printing temperature, layer thickness, and infill density to get the mechanical properties you want.
Material Flexibility
Investigate the bending strength and elasticity of PETG and PLA filaments. PETG is much more flexible than PLA, and would be a better choice for something that needs to bend or flex. The flexural strength and modulus of PETG are higher than those of PLA.
The reason behind this difference in flexibility lies in the molecular structure and crystallinity of PETG and PLA, with PETG being more flexible due to its more linear molecular structure. While PETG’s tensile strength of 40-50 MPa puts it beyond the realm of basic strength and into something more versatile.
Its 100% recyclability means it’s a little more sustainable than just strong. Its food-safe usage in the food industry is another example of beyond basic strength. It’s easier to get a glossy finish with PETG beyond basic strength.
The Post-Processing Reality
What is the best way to post-process 3D printed parts to achieve a great finish and hardness, especially PETG and PLA prints? We all know that post-processing — sanding, painting, gluing — can make or break a final product. All the more reason why post-processing is critical — it can make or break the value of the printed part from an aesthetic or functional perspective.
For example, you’ll want to smooth the surface before painting or finishing it other ways to attain a professional appearance. The surface of 3D printed parts can be brittle or require additional processing to achieve the desired texture or finish.
Sanding and Painting
Sanding and painting are two such post-processing techniques for PETG and PLA prints. How to sand and paint them best – using the right stuff to get a smooth finish. For instance, a progressive sanding of sandpaper grits can eliminate layer lines and produce a glass-like shine.
The selection among sanding and painting methods truthfully can have drastic impacts on the surface finish and durability of the printed part. Typically, PETG is easier to post-process than PLA, particularly for creating a glossy finish.
PETG and PLA sanding and painting considerations include surface roughness and chemical resistance, impacting the adhesion of paint and other coatings. Given the pros and cons of various sanding and painting techniques, you need to weigh the advantages and disadvantages of various sanding and painting materials for PETG and PLA.
For example, while you can coat your 3D printed parts in epoxy, it might require 24 hours to cure. Certain paints don’t stick as nicely to select 3D print materials and may necessitate extra priming or surface prep.
Gluing and Bonding
For PETG and PLA, gluing and bonding are important post-processing methods, especially if you’re piecing together multiple prints or affixing them to other materials. Gluing and bonding secrets and tips involve using the appropriate adhesives and surface preparation.
For instance, CA glue is great for gluing tiny precise things, but it’s an activator that reacts rapidly and must be used with care. Epoxy, on the other hand, can bond and coat 3D printed parts, but it can take up to 24 hours to cure.
There are a few things that affect PETG and PLA gluing and bonding, including surface roughness and chemical resistance. Even the selection of gluing and bonding materials matters for post-processing operations.
Certain 3D printing materials are more susceptible to water absorption, which can impact their longevity and may necessitate extra coating or treatment. Post-processing like sanding can be more difficult for some 3D printing materials, like PETG, which is flexible.
Advantages and disadvantages of various glues and bonds for PETG and PLA need consideration to meet strength and durability requirements.
Choosing Your 3D Printer Filament
Knowing which filament to choose for a particular 3D printing application is important — it will affect the quality, durability and performance of the printed part. Filament choice varies based on needs such as mechanical strength, thermal resistance and price. For example, in selecting a 3D printer filament, you need to think about the nozzle size (≥ 0.15mm is recommended).
- When printing with PLA or PETG, the layer height should be ≥ 0.05mm for a smooth finish. The considerations that drive filament choosing are complex.
- Mechanical strength is important because it defines how well your printed part will resist stress and strain.
- Thermal stability is important for maintaining the part’s shape and structure in different temperatures.
So, which is better – PLA or PETG? Well, it depends on the application and desired characteristics of your part. Wefab AI offers AI-enhanced DFM analysis along with material selection, enabling companies to optimize their 3D printing processes and select the most suitable filament for their specific needs.
Conclusion
In 3D printing, selecting the right filament—PETG or PLA—is critical for manufacturers in industries like climate tech, robotics, electric vehicles (EVs), and consumer hardware, as each offers distinct advantages tailored to specific project needs. PETG provides superior strength, flexibility, and durability, making it ideal for robust, functional parts, while PLA offers ease of printing and eco-friendly properties, perfect for prototypes and non-demanding applications. Choosing between them requires balancing factors like part strength, environmental exposure, and production goals to achieve optimal results.
Wefab.ai empowers manufacturers with its AI-driven platform, offering real-time filament selection guidance, design optimization, and process monitoring to ensure high-quality prints with up to 30% reduced lead times and minimal waste. Ready to enhance your 3D printing outcomes? Explore Wefab.ai’s advanced additive manufacturing capabilities and request an instant quote to achieve precision and efficiency in your projects.
Frequently Asked Questions
What is PETG and how is it used in 3D printing?
PETG (Polyethylene Terephthalate Glycol) is a strong, flexible 3D printing filament known for its durability and impact resistance. It’s widely used for functional parts in robotics and consumer hardware, ideal for applications requiring toughness.
Is PLA brittle compared to other 3D printing filaments?
Yes, PLA (Polylactic Acid) is relatively brittle and prone to cracking under stress compared to PETG. It’s best suited for prototypes or decorative items in non-demanding environments like consumer tech.
What are the primary applications for PETG in manufacturing?
PETG is used for durable, outdoor-compatible parts like enclosures and mechanical components in EVs and climate tech. Its resistance to UV and moisture makes it ideal for demanding applications.
Is PLA a biodegradable filament for 3D printing?
Yes, PLA is biodegradable and derived from renewable resources, making it an eco-friendly choice for sustainable manufacturing. It’s commonly used for non-functional prototypes in consumer hardware.
Which filament is stronger, PETG or PLA, for 3D printing?
PETG is significantly stronger and more impact-resistant than PLA, offering better durability for functional parts. It’s preferred for high-stress applications in robotics and automotive components.
How does Wefab.ai optimize filament selection for 3D printing?
Wefab.ai’s AI-driven platform analyzes project requirements to recommend PETG or PLA, ensuring optimal strength and printability. It reduces defects and lead times by up to 30% for climate tech and EV applications.
How does Wefab.ai enhance cost efficiency in PETG and PLA printing?
Wefab.ai provides real-time cost insights and material optimization, cutting 3D printing costs by up to 28% for consumer hardware projects. Its integrated platform ensures efficient production with minimal waste and high quality.
