PETG (polyethylene terephthalate glycol modified) is a variant of PET with glycol added. This combination prevents the material from crystallizing, making it softer and melting at a lower temperature. Ideal features when using it for FDM 3D printing.

PETG is more elastic than e.g. PET, it however retains the strength and interlayer bonding. It has an increased tendency to make small strings when printing. Therefore, it is recommended to increase its retraction relative to e.g. PLA; However, as always with retraction, this is something you have to test with regard to the exact amount needed.

There are various mixtures of PETG that make it less likely to make small strings and are easier to print with, one of which is e.g. EASY PET-G from Fiberlogy.

PETG is printed at 230-250 °C. A heated build plate is needed; it should be heated to 70-90 °C depending on what it is made of and whether you use tape, glue stick or something completely third to ensure adhesion.

PETG filament is hygroscopic, which means that it absorbs moisture from the surrounding air - it is therefore recommended to store the material in a drybox; a silica gel container at the bottom to bind any. moisture. If your PETG filament wheezes and pops when it is extruded, the reason is that it has absorbed too much water. This can be remedied by drying the filament in an oven with precise temperature control; such as a food dehydrator, or a decidedly filament dryer.

If you are considering drying it in a conventional oven, it is important to test the stability of the temperature as it can fluctuate a bit. In the worst case, this can cause the filament to fuse on the coil.

Depending on how much moisture the PETG filament contains, it is recommended to dry it for 8-24 hours at 65 °C.

Recommendations:

Print at 40-50 mm/s

Do not squeeze the filament against the build plate

Requires a heated build plate

Store dry, preferably in a drybox