PETG vs PLA

Hello everyone, today I will be providing a comprehensive comparison between PLA and PETG. Without any delay, let’s get started.

The main difference between PLA and PETG is their durability and flexibility. PLA is more brittle and rigid, while PETG is more flexible and impact-resistant.

In the world of 3D printing, many materials are available for use. PETG and PLA are two of the most widely used materials, each with its own set of pros and cons. Selecting the ideal material depends on individual requirements and preferences.

This article will provide a detailed comparison between PETG and PLA, analyzing their general properties, advantages, and drawbacks.

PETG VS PLA: Let’s Talk About PETG

PETG, or polyethylene terephthalate glycol, is a thermoplastic copolymer that is transparent and highly durable. Due to its low-molding temperatures, it boasts exceptional chemical resistance and is easily molded, heat-bent, and vacuum-formed into various shapes. It is a more substantial variation of PET (Polyethylene terephthalate).

PETG’s ability to mold at low temperatures also makes it highly suitable for applications that require intricate molding, deep cuts, and die cuts.

PETG plastic exhibits excellent bonding properties with solvents and adhesives, making it a versatile material for manufacturing processes such as bending, drilling, thermoforming, die-cutting, 3D printing, routing, and other heat-forming fabricating methods. Its beneficial properties make it a desirable material for various applications.

PETG General Properties

Property	Unit	Value
Density	0.0455 – 0.0462	lb/in^3
Tensile Strength	8.7 – 9.57	KSI
Yield Strength	6.95 – 7.67	KSI
Fracture Strength	1.92 – 2.31	KSI/in^0.5
Young’s Modulus	0.292 – 0.306	10^6 psi
Impact Strength	90.4 – 95.2	ft.lbf/in^2
Melting Point	81 – 91	°C
Max Service Temperature	51 – 65	°C
Thermal Expansion Coefficient	66.8 – 68.1	µstrain/°F

PETG Advantages

Food safe & Recyclable: PETG filament is considered safe in food containers and beverage bottles. Additionally, it is fully recyclable, which minimizes its impact on the environment and improves its acceptance as a preferred material due to the growing concerns for environmental safety.

Easy Coloring: PETG plastic can be easily colored to achieve the desired appearance. Moreover, its natural transparency enhances its versatility for various applications.

Limited Damaging: Polyethylene terephthalate glycol offers remarkable damage resistance comparable to more commonly used and mainstream materials like polycarbonate. Additionally, PETG is smooth and easy to work with, making it an ideal choice for professionals and practitioners.

Strong and Inexpensive: The exceptional strength and impact resistance of PETG make it well-suited for glazing applications and high-end displays. Additionally, these properties make it an excellent choice for 3D printing applications, such as creating rapid prototypes and signage.

Non-Toxic & Scentfree: PETG is non-toxic and has an almost negligible odor, making it a suitable material to work with anywhere.

PETG Applications

Food packaging, including containers and bottles

Medical devices, such as tubing and diagnostic equipment

Signage and displays, including trade show exhibits and retail displays

3D printing for creating prototypes, cosplay props, and other creative projects

Automotive parts, such as interior trim and light lenses

PLA vs PETG: Let’s Talk About PLA PLastic

PLA is a thermoplastic that is made from lactic monomers derived from natural sources like corn or sugarcane. It is a versatile and biodegradable plastic that can be used in various products. It is the second most commonly used bioplastic globally, with thermoplastic starch being the most popular. PLA has characteristics similar to Polypropylene (PP) and Polyethylene (PE). Additionally, producing PLA is cost-effective as it can be manufactured using existing machinery designed for conventional petroleum-based thermoplastics.

PLA’s extensive range of applications has made it a popular choice for manufacturers looking for strength and aesthetic appeal in a thermoplastic. It is frequently used in medical devices, food packaging, and other typical applications.

As PLA is composed of natural sugars, it becomes adhesive when heated, which helps models adhere to the printing bed and reduces the possibility of shrinking during printing. Moreover, the sugars emit a pleasant aroma similar to that of honey, making each printing session a little more enjoyable.

The PLA melting point and glass transition temperature are relatively low, meaning less heat or power is needed for printing purposes.

PLA General Properties

Property	Technical Name
Technical name	Polylactic Acid (PLA)
Chemical Formula	(C3H4O2)n
Tensile Strength	PLLA: 61 – 66 MPa (8840 – 9500 PSI) ***
Melt Temperature	PLLA: 157 – 170 °C (315 – 338 °F) **
Molding Temperature	PLLA: 178 – 240 °C (353 – 464 °F) **
Specific Gravity	PLLA: 1.24 *****
Flexural Strength	PLLA: 48 – 110 MPa (6,950 – 16,000 PSI) ***
Heat Deflection Temperature (HDT)	49 – 52 °C (121 – 126 °F) at 0.46 MPa (66 PSI) ****
Shrink Rate	PLLA: 0.37 – 0.41% (0.0037 – 0.0041 in/in)******

PLA Advantages

Easy to Print

PLA is straightforward to work with and is ideal for beginners.
It has a lower printing temperature compared to other materials, ranging from 180 to 220 degrees Celsius, which makes it compatible with most 3D printers.
PLA also does not require a heated bed, making it more convenient and cost-effective.

Versatile applications

PLA is suitable for various applications, including toys, household items, and decorative objects.
It can also be used in educational settings to create 3D models for science or engineering classes.
PLA is compatible with most 3D printers and can be used for professional and personal projects.

High-quality prints

PLA produces high-quality prints with a smooth surface finish and minimal warping or shrinkage.
It is ideal for creating models with intricate details and sharp edges.
PLA is available in various colors and finishes, making it a versatile material for 3D printing.

Low Viscosity

PLA is considered a safe and non-toxic material.
It does not produce any harmful fumes during the printing process, making it safe to use in enclosed spaces.
PLA is also FDA-approved for use in food contact applications, making it a suitable material for creating kitchen utensils or food packaging.

Environmentally friendly

PLA is made from renewable plant-based materials, making it an eco-friendly option.
It is biodegradable, meaning it can be broken down by natural processes without harming the environment.
PLA also produces fewer emissions during the printing process compared to other plastics.

PLA Applications

Medical implants and devices

Food packaging containers and utensils

3D printing of prototypes, models, and toys

Sustainable fashion and textiles

Biodegradable packaging materials

Differences in PLA and PETG 3D Printing properties

Property	PETG	PLA
Tensile strength	Yes, at 53.08 MPa	No, at 49.98 MPa
Elasticity and yield strength	Yes, at 238 J/m	No, at 152 J/m
Print cosmetic quality	No	Yes
Stringing tendency during printing	No	Yes
Cost	$20–25 per kg	$15–20 per kg
Compatibility with low-cost machines	No	Yes
Ease of sanding for models	No	Yes

PLA VS PETG: Part Accuracy Comparison

PLA is more suitable for maintaining precise parts due to its superior printability and reduced warping. However, it’s noteworthy that PLA tends to creep under continuous load. On the other hand, PETG is better for more minor features as it has higher viscosity in its molten state, leading to better bonding within layers.

PETG VS PLA: Applications Comparison

PETG is preferred for its strength, wear, and chemical resistance, making it an ideal choice for stressed components and moving parts. Model parts in motion or coming into contact with other components are better made from PETG as it provides greater resilience. Additionally, features exposed to water, sunlight, or heat will also benefit from PETG. On the other hand, PLA is better suited for low-stress and cosmetic applications, as well as components that require a better finish quality.

PETG VS PLA: Heat Resistance Comparison

PETG has higher heat resistance than PLA, with a glass transition temperature (Tg) of around 80°C compared to PLA’s Tg of about 60°C. PETG can withstand higher temperatures without deforming, making it a better choice for applications that require more heat resistance.

PETG VS PLA: Speed Comparison

PETG generally prints slower than PLA due to its higher melting temperature and viscosity. The slower printing speed helps ensure better layer adhesion and overall print quality. PLA can be printed faster due to its lower melting temperature and easier extrusion.

PLA VS PETG: Surface Comparision

The surface finish quality of both materials is similar. However, in some cases, PLA models may appear smoother due to their lower melt viscosity.

PLA VS PETG: Toxicity Comparision

PETG and PLA are food-safe and meet the GRAS (Generally Recognized As Safe) standard. However, two factors should be considered when using FDM/FFF parts in relation to food safety.

Overheating may cause depolymerization, which is more likely to occur in PLA because its polymer chains are more prone to scorching during extrusion.

Additionally, coloring agents used in the polymers may not be food-safe, and PLA may allow these dye agents to leak.

These factors do not necessarily mean that printed parts are unsafe for use with food, but caution should be exercised.

The Conclusion

In conclusion, PLA VS PETG are popular materials for 3D printing with their unique advantages and disadvantages. PLA is an excellent option for beginners or for creating models with intricate details, while PETG is more durable and heat-resistant, making it suitable for functional parts. Ultimately, the choice between the two materials will depend on the specific needs of your project. By understanding the properties and characteristics of each material, you can make an informed decision and achieve successful 3D prints.

Thanks for reading. Share your views and questions in the comment section.