Everything you need to know about PETG

Have you ever considered venturing in 3D printing?  Then you should know about PETG, which is a commonly used filament in 3D printing. There is no need to worry if you have no clue about it because this article will provide everything you need to know about PETG. So, let us get started.

PETG, or otherwise called glycolic polyester, is a thermoplastic that is used by many people as an additive in 3D printing. This material combines both the strength of ABS and the simplicity of PLA 3D printing, which makes it an impressive printing filament to use. Additionally, it is essential to understand that PETG is an amorphous plastic that can be recycled, and it has the same chemical composition as polyethylene terephthalate (PET). The addition of glycol to PETG makes it more fragile compared to other brittle plastic filaments. This article reviews all the essential information on PETG, including its characteristics, advantages, disadvantages, comparison with different filaments, and questions that are mostly asked about PETG. In other words, it is everything you need to know about PETG.

Before we proceed further, we need to understand something about PET. Pet is a widely known material in the 3D printing industry since it has been used in the production of food bottles and containers for decades as a replacement for PVC. Additionally, PET is used in the manufacture of synthetic fibers for clothing. Overall, PET accounts for almost 185 of plastic productions globally, making it one of the most used polymers. The unique characteristics of PET include excellent impact resistance, transparency, and stability in dimensions. However, PET has some issues of overheating when it is used for 3D printing, and that is where PETG filament comes in.

The characteristics of PETG

PETG is a copolymer, which combines the properties of PET and glycol. The addition of glycol reduces the overheating effect of PET. The known characteristics of PETG include:

  • Hardness
  • Resistance to impact and chemicals
  • Transparency
  • Ductility
  • Excellent thermal stability
  • Easy to extrude

Accordingly, PETG printing filament is used in making food packaging because it is more compatible with food and assures safety. On the downside, PETG requires a heating plate to prevent it from warping similar to the one experienced in ABS 3D printing. A BuildTak sheet is commonly used to enhance the grip of PETG when heating. Besides, PETG is prone to scratches compared to other materials like PLA. However, PETG is highly absorbent and takes up moisture more quickly.

Considering the printing qualities, PETG has an extrusion temperature of between 220 degrees Celsius and 260 degrees Celsius with a printing speed of between 40mm and 60mm per second.

The benefits of PETG filament compared to PET.

PETG printing filaments are currently prevalent in the market because it has the edge over other 3D printing filaments, especially PET. There are many benefits that PETG offers compared to PET as a 3D printing material, and here are some of the reasons why t is preferred to PET.

  • PETG is more durable
  • PETG has a high resistance to impact than PET
  • PETG can be sterilized
  • PETG is RF sealable while PET is not
  • The addition of glycol to PETG makes it fragile and is not as breakable as PET.

Everything you need to know about PETG

The advantages of using PETG filament for FDM 3D printing

PETG is well known to combine the strength of ABS and the reliability of PLA in its structure, making it an excellent 3D printing filament. Below are some of the advantages of using PETG filament for FDM 3D printing.

  • PETG has an excellent layer adhesion
  • PETG prints do not warp or shrink easily
  • PETG can be recycled along with its prints and misprints.

The disadvantages of PETG as a 3D printing filament

The disadvantages of PETG are not many. However, it still has some drawbacks worth looking at. The first notable con is that PETG is more prone to scratching compared to PET. Additionally, the mechanical properties of PETG are easily weakened by UV light. Besides these, some makers also regard PETG as one of the most challenging materials to print with because it requires some form of a “sweet spot” with settings before printing.

When to use PETG filament

PETG is one of the best materials, and it stands out among other filaments because of its excellent flexibility, strength, and resistance to both temperature and impact. These properties make PETG an ideal material for 3D printing in objects that may experience sudden stress, for instance, mechanical components, parts of 3D printers, and other protective elements.

Accordingly, PETG filament is the most suitable material for food packages and bottles.

PETG vs PLA

Polylactic Acid (PLA) is also a thermoplastic material like PETG, which is also classified among the polyester plastics. Similarly, PLA is commonly used in 3D printing because it is easy to print and is also biodegradable. PLA filaments come in a wide variety of colours and many manufacturers like using them for production of different parts. Additionally, the chemical and mechanical properties of PLA allow the addition of other elements like metal powder, wood, coffee, and hemp, among others.

Everything you need to know about PETG

How does PETG filament compare to PLA filament?

The most notable difference between using PLA and PETG for 3D printing is that PLA is more natural to use and handle compared to PETG. Additionally, PLA does not have many errors in printing. Here is how the materials compare:

  • Both PLA and PETG experience minor shrinkage upon cooling.
  • Both PLA and PETG are safe to use in food containers and bottles.
  • PLA  does not scratch as easily as PETG
  • PLA is more affordable compared to PETG.
  • PLA filaments offer a wide range of printing variations compared to PETG.
  • Both PLA and PETG are user-friendly. However, PETG is more robust, durable and can withstand extreme impact and temperature.

PETG vs ABS

Acrylonitrile Butadiene Styrene (ABS) is one of the most affordable thermoplastics in the market. This material is slightly flexible, durable, lightweight, and can be extruded easily. These features make it a perfect 3D printing material. ABS is commonly used in bicycle helmets and LEGO bricks.

On the downside, ABS requires higher temperatures to melt, usually between 210 degrees Celsius and 250 degrees Celsius. Additionally, a heated build platform is needed for one to print using ABS. This platform helps in preventing faster cooling of the first layer of the print, which would instead cause warping of the plastic.

Another disadvantage of using ABS as a 3D printer filament is that it produces concentrated fumes during printing, which can be harmful to people with respiratory conditions.

How does PETG filament compare to ABS filament?

Here is how these two 3D printing filaments compare to each other:

  • ABS filament is more flexible and does not snap easily.
  • ABS filament needs a heated platform for 3D printing to prevent warping, while PETG does not.
  • PETG is safe for use in food containers, while ABS is not.
  • Both PETG and ABS filaments shrink slightly during cooling.
  • Both PETG and ABS can be recycled. However, they are not biodegradable.
  • Both PETG and ABS are robust, durable, and have excellent resistance to impact.

Frequently asked questions about PETG.

Is it safe to use PETG in food containers?

PETG is entirely food safe if handled correctly. A much as it commonly used for food containers, it is essential to check the specifications from different manufacturers on this factor.

Does PETG come in a wide variety of colors?

PETG comes in a wide variety of colors the same way PLA and ABS do.

What is the optimal print setting for PETG?

The optimal print setting for PETG varies significantly depending on the manufacturer of the filament. However, there is a standard range of specifications that can be expected from almost every spool of PETG filament. The standard print temperature should range between 220 degrees Celsius and 250 degrees Celsius with the print bed temperature being somewhere between 50 degrees Celsius and 75 degrees Celsius. The good news is that PETG is not a brittle material and can be printed over various temperature ranges as much the heat does not go way off-limits.

Everything you need to know about PETG

How do you know the best print setting for PETG?

There are many ways to ensure print quality and success.  The first option is looking at the first layer of the print. If it is not sluggish, then you may have to raise the print temperature slightly. Additionally, start with a low print speed of around 15mm per second. This will help you determine the best setting for the material. Once you have noticed where the material is best printed, adjust the print speed.

Can I print without a heated bed?

It is not a must to have a heated bed for printing with PETG. However, having one adds more quality by reducing the chances of warping when printing in large volumes. Some people print with PETG filament successfully using Ultimaker 2 Go in place of a heated bed, but it requires more time to find the best print settings.

Like any 3D printing process, you will have to be patient and willing to experiment to find the right setting and methods of printing with PETG filament without using a heated bed.

The bottom line

PETG is one of the most used 3D printing filaments in the market due to its impressive mechanical and chemical properties. Knowing these properties helps in determining where to use PETG or other plastics as alternatives.