PETG filament for 3D printing: learning about plastic materials

A little guide to learn about the materials: PETG filament!

 

What is PETG

PETG is a transparent polyethylene tereflato capolyester: it is a modified version of PET. The “G” stands for “modified glycol”, which is added to the composition of the material during the polymerization. The result is a lighter filament, less fragile and easier to use than its basic form of PET.

It is used in the exhibitors of sales points, signs, luminous signs, signage and numerous kinds of construction details, etc. This material is difficult to attack by chemical agents, as shown by the containers in which it is stored gasoline, naphtha, solvents of various kinds.

It is an extremely resistant material that allows to obtain sturdy and long-lasting prints. Thanks to the low shrinkage coefficient it makes this material excellent for 3D prints that have large flat surfaces.

Summary of the characteristics of PETG

  1. Odorless: it is completely odorless, fundamental characteristic for domestic use, even if odorless does not mean non-toxic.
  2. Low shrinkage rate: keeps measurements faithfully cooling, ideal for large prints.
  3. Hydrophobic: Does not absorb water, and therefore does not substantially deteriorate
  4. High impact resistance: the high resistance makes it the ideal material for everything that moves, including quadcopters, remote-controlled cars and robots (although it can be scratched easily).
  5. High mechanical strength and excellent flexibility: ideal to be used for objects subjected to mechanical stress, it is a hard, extremely resistant and flexible material. This is also due to an excellent coefficient of adhesion between layers. This characteristic makes it unsuitable for printing with too many supports. The very strong adhesion between layers means that these are not so simple to detach when finished.
  6. High chemical resistance: extremely resistant to the action of chemical agents, acids and alkalis. Typically PETG is translucent, giving the object a glossy finish on the surface.

Why PETG

PETG is a 100% recyclable thermoplastic product, allowing the creation of resistant but more flexible ABS objects. It has a low shrinkage coefficient, is transparent, it does not absorb water and has excellent impact resistance. It also satisfies the requirements of DIN 52290 which concerns the production of protective glass, it is suitable for thermoforming and for screen printing it is suitable for contact with food, it is glued and welded.

Application of PETG

This material is used in the furniture sector, as for example the shelters/skylights (use anti-U.V. version), viewers, food containers (even at low temperatures), exhibitors, machine guards. In other cases, even greater flexibility may be needed, with the need to resort to TPU, flexible PLA or Nylon.

One of its best features, the impact resistance, makes it ideal for example to create objects that can be subjected to impacts such as drones.

PETG vs ABS and PLA

The PETG in recent times substituting the ABS, manages to have the same characteristics of strength and strength, however, being much easier to print.

The PETG filament has the reputation of combining the functionality of ABS (more resistant, resistant to temperature, longer lasting) and the reliability of the PLA (easy to print) in a single material. The adhesion of the layer is generally excellent.

The ABS has its problems, especially warping and separation of the layers, for this reason it needs a closed printing chamber. PETG is not immune to problems, in fact it suffers a bit of stringing, but in general, the difficulty of printing is much more similar to PLA.

We can say that:

  • PETG is particularly durable, and considerably more flexible than PLA and ABS, but also softer. It’s hard to break it. If the object to be realized is a container or a wrapper which must have characteristics of high resistance, PETG is the most suitable material (with the exception of Nylon 12, which however has greater printing difficulties and higher costs).
  • PETG is also very robust, and at all fragile, but can be scratched with ease, being significantly less harsh than ABS.

Tips and Tricks: Extrusion with Felfil Evo

  1. Adjust the temperature accurately. The first attempts can be made between 205° and 210°, depending on the type of extortion.
  2. The PETG requires an extrusion rate equal to the PLA and lower than the ABS.
  3.  Unlike ABS and PLA it does not need to be dried.