What is PETG?
PETG is an abbreviation for Polyethylene Terephthalate (with a glycol modification) which is one of the most common polymers used today. It’s used to make water bottles, food packaging, Baby Feeding bottle, and countless other common plastic items. As a 3D printing filament, PETG plastic has proven its worth as a durable material that is easy to use. It combines the most useful characteristics of ABS filament (the rigidity and mechanical properties for functional parts) with the ease of printing that PLA filament affords. Kind of a “best of both worlds” scenario.
PETG is the most common form of PET used for 3D printing filament. The G stands for glycol-modified, and this makes the resulting resin clearer and less brittle than raw PET. Raw PET typically isn’t used for 3D printing. PETE, PETP, PETT, and PET-P are modified versions of PET (called copolymers), but by far the most common material used in 3D printing is PETG.
PETG as 3D Print Filament, what it is used for?
In short, this is a really tough material, it's extremely durable and prints without odor. Once you’ve dialed in the correct print settings, it prints nicely too. Users report similar finish quality to PLA.
Here are the main benefits of printing with this material and common PETG filament properties:
- Very durable, it’s more flexible than PLA or ABS, but also a little softer. You’d have a hard job breaking it in half, so if an ‘unbreakable’ case or enclosure is what you need, PETG trumps pretty much everything.
- It has very low shrinkage, and therefore no warping. Ideal for printing big stuff.
- PETG is also very strong, it’s not brittle but can be scratched more easily than ABS.
- PETG plastic makes a terrible support structure, because it sticks so well and because it sticks so well, layer adhesion is fantastic, so prints come out strong.
- It has great chemical resistance, along with acid, alkali and water resistance
- Odorless when printing
Typically, PETG filament is supplied in a range of translucent colors, and prints with a nice glossy finish. It makes it ideal for printing anything that needs to be shatterproof or translucent. Many are taking the leap from using PLA or ABS to just using PETG.
Hardware requirement for PETG printing
Best Practices …
Good build surface:
Some 3D printers come with a glass bed or blue painter’s tape installed on the bed. Although these surfaces might work fine for PETG, it is recommended to use a heated build platform for the best results. The heated bed can significantly improve the first layer adhesion, making things much easier for future prints. Many of these heated beds come with a glass surface, allowing you to print directly on the bed without needing to apply any additional layers of tape or glue.
Retraction setting to reduce stringing
One of the few common issues that we see with PETG is stringing. These strings are thin hairs, similar to a spider web, that run between the different surface of your 3D print. Preventing these strings requires precisely calibrated retraction settings, so make sure to adjust your retraction distance and speed for the best results. Try to increase retraction distance, retraction speed, and travel speed, within reasonable limits.
Optimize the extruder setting to prevent blobs
When 3D printing at higher temperatures associated with PETG, you may notice small blobs on the surface of your model. These print defects typically occur at the beginning or end of each segment, where the extruder has to suddenly start or stop extruding plastic. There are several ways to eliminate these print defects such as enabling “Extra Restart Distance” or “Coasting” options located in the Extruder tab. Keeping the right temperature sometimes help in reducing such problem.
Keep PETG Dry
PETG is hygroscopic, meaning that it easily absorbs moisture from the air. This moisture deteriorates the material itself and can ruin an otherwise fine spool of filament. As such, keep your filament stored in a dry environment, like in an airtight bag or box filled with desiccant packs. This should preserve the filament and prevent it from absorbing too much moisture. Read my blog ……
“Once you’re set up correctly, you’ll find printing with PETG is riding your bike with wind on your face, just like a dream. No warp, odorless printing, and great layer adhesion are just some of the excellent properties with printing this filament”