Everything You Need to Know About PETG in 3D Printing

Source: 3dnatives.com

The use of PETG in 3D printing is now increasingly widespread. PETG or glycol-modified polyester (G), is a thermoplastic that combines the simplicity of 3D printing with PLA and the resistance of ABS. It is an amorphous plastic that can be 100% recycled, with the same chemical composition as polyethylene terephthalate (PET). Glycol is added to make the plastic more resistant and increase its durability. Today we will analyze the characteristics of PETG, its printing parameters and its main applications.

First, let's go back to PET. It is a well-known material in the industry because, since the 1990s, it has been used in the production of bottles and food packaging, replacing PVC. It is also used in the production of synthetic fibers for clothing. It is one of the most widely used polymers on the market, covering 18% of global plastic production worldwide. It is known for its good impact resistance, transparency and dimensional stability. On the other hand, it is a plastic that is subject to overheating when used for 3D printing: this is why it is necessary to use PETG.

The characteristics of PETG in 3D printing

PETG is a co-polymer that combines the properties of PET and glycol. The addition of glycol reduces the overheating problems of PET and, consequently, increases its resistance. Among the main characteristics of PETG are hardness, resistance to impacts and chemicals, transparency and ductility. It is an easily extruded material with good thermal stability. It is particularly appreciated for its food compatibility. The disadvantage is that it requires a heating plate to avoid the warping effect found in 3D printing ABS. Even if the warping percentage is low, it is better to use a sheet of BuildTak to ensure that the material holds. It is also more prone to scratches than PLA. Finally, it can absorb moisture quickly and is best stored in a cool, dry environment.

Regarding printing parameters, PETG has an extrusion temperature between 220 and 260°C and we recommend heating the bed no more than 80°C. The printing speed is 40-60mm/s. Print supports are not very suitable as PETG has a sticky appearance that will make it difficult to remove them.

Top PETG Filament Manufacturers

Most of the manufacturers of 3D printer filaments today they work with PETG: just think of Formfutura, ColorFabb, 3DXTech, Innofil3D or the Zortrax brand. In terms of format, as with other filaments, there are spools of 1.75 or 2.85 mm in diameter, with different weights depending on the needs. It should be noted that PETG is often reinforced with carbon fibers, which increases the rigidity of the piece while optimizing its final weight. Nanovia, for example, offers this solution in its filaments. It has also developed a PETG reinforced with aramid fiber that reduces the fragility of PETG while increasing its rigidity.

Finally, from the price point of view, it should be noted that it is slightly more expensive than PLA: a classic 750 gram PETG spool costs between €30 and €35 ​​– naturally it will have a higher price, between €55 and €70.