Filament Types for 3D Printers

3D printing is now a trusted, legitimate means of fabrication with many industrial applications, whether it’s quick, accurate modelling and prototyping, or the construction of fully usable, robust components in every branch of engineering imaginable.

There still remains a wide choice of filaments, however, and each comes with its set of strengths and weaknesses. That’s what we’ll be looking at here.

A filament is a thermoplastic, which means a substance that becomes liquid when it is heated, but sets into a solid when it cools. In 3D printing, they come in long strands on a spool, which can be fed into the 3D printer, where it is heated and deposited onto the print bed and then onto subsequent layers of filament, forming a three-dimensional shape.

Just as there are many different kinds of plastic, each with its own properties, so there is a range of filaments available to 3D print with. The various materials come with their own temperature tolerances, chemical reactivity, solubility in various fluids, safety for food storage and preparation, and other such properties.

TPE Filament

Look closely at the name “thermoplastic elastomers” (TPE) and you’ll see that it’s a material with a good deal of flexibility and elasticity. You almost certainly won’t break a TPE model if you drop it, but nor will it be suitable for self-standing, intricately detailed models, as gravity will make it sag. It can be tricky to print but is excellent for soft components like mats, protective cases or washers.

Nylon Filament

Nylon is one of the oldest plastics, pioneered in the 1920s, and it remains an important fabric in all sorts of applications, from fishing lines to tough fabrication components like screws. Nylon 3D printer filament requires higher nozzle and bed temperatures than PLA which not all tabletop printers can handle, but the result is a tough, flexible and resilient plastic. One interesting feature is that it can be dyed before or after printing.

Polycarbonate Filament

Polycarbonate 3D printer filament (PC) is a very strong material, able to withstand impacts and also temperatures above 100 °C, making it ideal for safety equipment and any other application where it will be exposed to stress. It does require incredibly high nozzle temperatures, however, around the 300 °C mark.

3D Printer Wood Filament

You can achieve a relatively realistic wood effect with 3D printer wood filament, which is essentially PLA impregnated with wood fibre. It looks surprisingly realistic, partly down to the layering resembling grain, although it should only be used for display, not structurally, and definitely shouldn’t be tossed on the fire!

Metal Filament 3D Printer

Similar to wood above, metal filament is simply PLA mixed with metal powder to give a metallic finish to your models. It’s available in copper, silver, brass and other shades, and does have a dull metallic finish, rather like pewter, aluminium or aged brass.

So which is the best filament? It depends on aesthetics, ease of use, load-bearing requirements, flexibility, cost and a host of other factors. At the moment, PLA is considered the best all-rounder because it’s cheap, easy to work with and gives reasonably strong and precise finished products. You’d never make jet engine fan blades out of PLA, but that’s not what regular people use 3D printing for – it’s still largely a prototyping and display medium.

Most Flexible 3D Printer Filament

If flexibility is important, TPE wins by some distance. Its finished product has a rubbery, flexible and stretchable form, which makes it practically unbreakable unless it’s cut or greatly overstretched.

Strongest 3D Printer Filament

If strength is important, stick with polycarbonate, as it’s about as strong as you can get with 3D-printed plastic. If you’re using a regular consumer 3D printer, however, it’s likely that it won’t be set up to print PC, so it might be time for an upgrade to your 3D printer.