Just like a standard paper printer, 3D printers need cartridges of material to operate. In the case of fused deposition modelling 3D (also known as 3D FDM), the machines on the market use plastic filaments sold on reels or in closed cartridges.
FDM printing filaments are part of the “thermoplastic” family: they become soft and malleable when they are heated and go hard when they cool.
The most common filaments on the market are ABS and PLA.
ABS (acrylonitrile butadiene styrene) is one of the most widely used plastics in the world. It is the plastic used for Lego bricks, and is also prevalent in the automotive industry, domestic appliances, and even the medical sector.
ABS is printed at a temperature of approximately 230°C, but it requires a 3D printer with a heated platform because it tends to retract. ABS is a hard-wearing and slightly flexible plastic, which is why it is preferred to PLA for making mechanical parts.
To avoid inhaling the fine particles of ABS, it is recommended to use this material in a room with sufficient ventilation, unless you have a 3D printer with an enclosed compartment and air filter.
The range of ABS filaments from 3D printer manufacturer, Zortrax
As for PLA (polylactic acid plastic), it is a biopolymer, an organic plastic composed primarily of corn starch. Printing with PLA requires a lower temperature than ABS, between 180 and 220°C. PLA does not require a heated platform and is one of the easiest materials for printing. Objects printed with PLA tend to have a glossier and smoother finish than ABS printed-objects, but they are less resistant to shocks and temperature.
XYZprinting protected cartridges
These two plastics are the main materials sold today, but there are many “exotic” filaments, composite filaments, as well as high-performance filaments for professional use, as well as other filaments for support structures.
These filaments include flexible filaments, which as their name suggests are elastic and malleable. Due to this flexibility, to make a perfect object, some experience and a heated platform are required.
An example of objects printed with flexible filament
Composite filaments are made with a blend of plastic, usually PLA, and another natural material. For example, there are filaments with wood fibres, stone, and even metallic powder which gives a metal-like finish once it has been sanded.
“High-performance” filaments have interesting technical properties such as: good solidity (Nylon or Carbon filament), resistance to high temperatures (like PC filament) or corrosion. The can also be electrically conductive or compliant with certain biocompatibility or food handling standards (such as PET). These filaments are mainly for professional use and often require more sophisticated printers.
Some filaments have a metallic finish
Support structure filaments are made with soluble plastic such as HIPS or PVA. They are used to create supportive structures for complex objects, impossible to print without a detachable structure. A printer with a double extruder nozzle is required to join the desired material to the support structure material.
Generally, HIPS is joined to ABS, and PVA to PLA given their common properties. After printing, the printed object is simply dipped in soluble solution (limonene for HIPS, water for PVA) to remove the support structure.