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中文简体/ What is PETG? /
PETG, or polyethylene terephthalate, is a thermoplastic that is one of the most widely used polymers in additive manufacturing. Notably, it is a popular choice for filament and fused deposition modeling because it combines the simplicity of PLA 3D printing with the strength of ABS. It is an amorphous plastic that is 100% recyclable and chemically identical to polyethylene terephthalate, better known by its acronym PET. To get the best out of the material, the following guide will outline the properties of PETG, what you need to know about 3D printing with PETG, its main applications and manufacturers.
/PETG Production and Characteristics/
In order to understand PETG, it's important to first look at PET itself.PET is a well-known material in industry, estimated to be worth around $44.3B in 2022 alone, as it has been used since the 1990s to make bottles and packaging, replacing PVC.It also allows for the production of synthetic fibers used in clothing. But the use of pure PET in 3D printing is not common. Instead, ethylene glycol (G) is added to PET at the molecular level, giving the material greater strength and durability while also making it more flexible.
PETG is therefore a copolymer that combines the properties of PET and glycol. The addition of the latter reduces PET's overheating problems (which prevent it from being used in additive manufacturing) and its brittleness.PETG's key characteristics include its hardness, impact and chemical resistance, transparency and ductility. It is an easy-to-extrude material with good thermal stability. It is particularly appreciated for its food compatibility.
PETG3D Printing / PETG3D Printing / PETG3D Printing
Regarding printing parameters, PETG can be extruded at temperatures between 220°C and 260°C. It is recommended to use a heated print bed, which can be heated between 75°C and 90°C. The ideal printing speed is 40-60 mm/s. The ideal print speed is 40-60 mm/s. Carriers with PETG are not recommended, as it adheres well to itself, making it difficult to remove after printing. Nevertheless, this material is relatively easy to print, if not harder than PLA, while still offering good performance. That said, there are drawbacks to this material. Notably, it requires a heated plate to avoid the warping effect that can occur with PETG - even if warping is low, it's best to use BuildTak sheets to ensure material grip. It also scratches more easily than PLA. Finally, it absorbs moisture quickly and must be stored in a cool, dry environment. Also, be aware that due to its high viscosity, it can clog printheads.
/ PETG Applications /
PETG can be used in many different applications. The first one that comes to mind is of course the food industry. Due to its relationship with PET, PETG is not only waterproof, but according to FDA regulations, PETG can come into contact with food. This makes it particularly suitable for packaging in industry. But that's not all. In addition, PETG is sterilizable, making it also suitable for use as an orthotic material as well as for medical devices and prostheses. As expected, PETG is also widely used for prototyping due to its relative cost-effectiveness and adequate performance. In addition, due to its heat and chemical resistance, it can even be used for more durable applications such as tools, test assemblies or end-use parts for machines.
