Alex, Author at re:3D | Life-Sized Affordable 3D Printing

Polyethylene Terephthalate (PET) is a durable material with a glossy appearance. Outside of PLA and ABS, PET is a very common filament. A variation of PET, PETG, is often sold as a filament as well. PETG is a form of Polyethylene Terephthalate (PET) with glycol introduced. The introduction of glycol causes PET to become more flexible and resistant to impacts. PETG also resists shrinking and sticks to other materials easily, unlike other materials that print at a similar nozzle temperature to PETG. These properties allow PETG to fill a role between PLA and ABS as a strong, easy to print material. PETG is used for water bottles, oil containers, and plastic packaging. Recycled versions of PET and PETG, often called rPET, is a go-to recycled material for many closed loop applications. For those looking to branch from PLA and create more durable parts, PET, PETG, and rPET are good choices.

PETG excels when you take advantage of its material properties. If you need something that can endure the outdoors, PETG’s impact strength makes it a suitable material. Its chemical makeup makes it bond easily to other materials and serve as a versatile support material.

PET is one of the most commonly recycled materials. Reground PET is often turned into rPET filament for 3D printing. PETG is technically recyclable, but it is often rejected from commercial recycling centers due to its low melting point causing issues when recycled with other materials. It may be possible to regrind PETG and to reuse it in pellet fed printers such as GBX.

Polylactic Acid, more commonly known as PLA, is one of the most frequently used materials in 3D printing. Its popularity comes from its ease of use, organic nature, and relatively strong mechanical properties. PLA is also inexpensive making it a great entry-level material. PLA is made up of naturally occurring, organic lactic acid chains which generally makes it useful in organic settings such as medical applications. Its chemical nature also makes it easy to recycle and reuse. PLA also boasts strong mechanical properties and user-friendly thermal properties that make it easy to print with. For those looking for a place to start in additive manufacturing, PLA is an excellent choice.

PLA is a great material for applications that require rapid prototyping and strong parts. Its ease of use and low cost make it suitable when a part may be frequently reprinted as is the case in prototyping and architecture. For those who are still learning to 3D print, or for those who are teaching others, PLA is a great introduction to 3D printing. The thermal properties of PLA also make it useful as an alternative to lost wax casting where the PLA is burned away instead of a wax.

PLA is created from organic sources, making it sustainable to produce. It is possible to recycle through composting. Furthermore, PLA is easily reused if ground up and reused in pellet printers such as GBX. PLA can only be reused a limited amount of times due to its compostable nature. PLA is not easily recycled at commercial recycling centers due to it being lumped into code 7, “other plastics”, in the resin identification number system.