PET-G and PLA materials are thermoplastic plastics from the group of polyesters. Each of these materials is great for the 3D printing process in FDM technology. So what are the differences between these two types of materials? When should you choose PLA, and when PET-G is the optimal solution?
The following article presents the most important similarities and differences between PLA and PET-G.
The first aspect that is worth paying attention to is their mechanical properties. PLA is an “environmentally friendly” material with high rigidity, while its strength is not as high as with PET-G. On the other hand, PET-G has a much lower stiffness, so in the event of exposure to impact this material will undergo temporary deformation. Therefore, when choosing material for printing, we should pay special attention to the conditions in which the 3D printed element will work.
If our print will be exposed to environmental conditions, PET-G will be a better choice because it is definitely more durable not only to weather changes, but also to sunlight. On the other hand, polylactide can be covered with a protective layer that will protect the printout from the harmful effects of environmental factors. When choosing material for 3D printing intended for outdoor work, it is worth paying attention to the alternative to classic filaments, ASA.
PET-G also has a higher resistance to high temperatures of up to 100°C and even 120°C. For PLA, the recommended operating temperature is below 55 ° C. Polylactide print left behind the car window on a summer day may be deformed, while PET-G will retain its properties. Temperature values may vary slightly, depending on the filament producer.
PLA is known for its biodegradability. It is a material made from natural ingredients, thanks to which it gained the fame of “environmentally friendly material”. PET-G can be recycled.
If you need a thermoactive material or filament with unusual visual properties, PLA will be the basis for this material. Original filaments are usually produced using polylactide. More about unobvious PLA-based 3D printing materials in an earlier article.
Both filaments are relatively easy to print, they do not need a closed chamber. Nevertheless, PET-G requires a heated table. Production of complex structures may be easier with PLA, because the range of compatible support materials for polylactide is definitely larger than for PET-G.
PLA has better adhesion to the ground and does not require a heated table. For PET-G, it is required to be heated to a temperature of 50-70 ° C. For better print adhesion to the substrate, special PVA adhesives can be used. Due to the very good adhesion of PET-G to the table, there is no need to use preparations that increase adhesion.
The printing temperature depends on the manufacturer. PLA usually requires lower temperatures than PET-G. Process parameters should always be checked and correlated with the manufacturer’s recommendations. Too low nozzle temperature may result in clogging, and too high temperature may cause carbonization of the filament inside the head.
| PLA | PETG | |
|---|---|---|
| Material density [g/cm3] | 1,22 | 1,13 |
| 3D printing temperature [°C] | 185-230°C | 240-260°C |
| Bed temperature [°C] | 0-45°C | 80°C |
| Aplication | – functional prototyping – functional tools – interior design and decoration – prototyping industrial designs to visualize the concept | – 3D printing elements acting as energy adsorbents – production of gaskets with high chemical resistance – manufacture of parts for final use – production instrumentation – functional prototyping manufacturing elements – related to prosthetics, orthoses, car parts or various consumer products |
In the case of PLA, post-processing is definitely easier. The material can easily be covered with acrylic paint. Remember that you should do several attempts to paint the printout to check the adhesion of the coating to the printout. In addition, support removal is easier with polylactide prints. PET-G has very high layer adhesion, and thus, support structures also adhere better to the element.
PLA and PET-G have many common features, but there are a number of differences between the two filaments. PLA has lower temperature and mechanical resistance. On the other hand, it can easily be subjected to additional processing (e.g. easily covered with acrylic paint), and gluing prints is not as complicated as in the case of PET-G. Nevertheless, if we are looking for a material resistant to weather conditions and high temperatures, we should definitely choose PET-G. It is a material much more suitable for engineering and automotive applications and the production of components that require chemical resistance. PLA is perfect for prototyping conceptual designs and functional prototyping.