PET-G is gaining more and more popularity among users of 3D printers. It owes it to its properties that make it a great alternative to other materials commonly used in low-budget 3D printing such as ABS and PLA. How is it different from them?
PET-G is a copolymer of poly (ethylene terephthalate), which we know mainly as a material for the production of packaging for food products, with ethylene glycol. The combination of these two substances results in a thermoplastic with different properties to those of ordinary PET in beverage bottles. Thanks to the addition of glycol, the polymer is great for use, among others, in FFF technology. It is recyclable like PET.
The material combines the most desirable features of ABS and PLA. First of all, thanks to very good layer adhesion, it is more durable, and prints under pressure turn out to be quite flexible. In addition, it has a slight shrinkage of material, so although it is advisable to use a heated table to prevent prints from peeling off, it is possible to print on a device not equipped with a closed working chamber. Other advantages often include very good dimensional accuracy of prints.
Despite the attractive set of positive features, PET-G is not free from defects. It is necessary to mention here the peculiar fragility through which the prints may crack under the influence of impact. This property is deepened by improper selection of printing parameters – like too much cooling or too high extruder temperature. The fracture, which rarely runs along the layers, is accompanied by a large amount of debris.
Among users of low-budget 3D printers, PET-G has the reputation of being quite easy to 3D print – due to low shrinkage, low sensitivity to quick print cooling and good adhesion to the table. It is printed from it at a temperature in the range of about 230-250°C. It releases a very small amount of volatile organic compounds with no perceptible odor. Caution is advised when removing supports due to debris.
This polymer works very well for printing various types of handles and mechanical elements. It can be ground and drilled holes in it. It is resistant to chemicals, including solvents, and relatively resistant to ultraviolet radiation and moisture. The maximum service temperature of PET-G objects is around 70°C – exposed to higher temperatures they can start to soften. Because PET-G is naturally transparent, transparent filaments are available on the market to enable the creation of semi-transparent objects in different colors.