What is PETG filament?

What is it?

Tell me more, tell me more !

PETG (Polyethylene Terephthalate Glycol) is a durable, hardwearing polyester combination that can be used as a filament in FDM (Fused Deposition Modelling) 3D printing. As a printing material it has excellent flexibility, durability, and chemical resistance. This makes it an ideal choice for 3D printing enthusiasts who may want to try more than just model making.

That being said, it is still a good choice for those modellers who need good impact resistance and additional strength in their creations. It’s also great for models requiring snap together or movable parts.

The History and the Science

Where it all began to grow

PET was first formulated in 1941 by the British scientists Dickson and Whinfield who patented their product for the manufacture of fibres. These fibres were intended to replace cotton as a source material for uses in textile manufacturing. It did however take until 1946 for PETG to be settled into the industry but it is still widely used today.

By 1952 use of PET had expanded into food packaging in the form of transparent film and then in 1976 in the use of rigid drinks bottles. Drinks with low oxygen sensitivity were particularly best suited such as carbonated soft drinks, mineral water, and beer. The significance of this can’t be understated as it made PET the most used plastic in the world.

PETG itself is a copolymerisation of the original PET. The addition of ethylene glycol (the “G”) made the PET less prone to crystallization and reduced its melting point. It also had a better thermal stability allowing it to be used to create flexible extruded parts as made by FDM 3D printers.

Image: A selection of drinks bottles made from PETG (Source: Plastics Today)

PETG Filament: A Rough Guide (Part 1)