There’s a whole world of 3D printer filaments out there, but where do you start? Learn which plastic is suitable for which application and why you shouldn’t try to print metal with your RepRap.
Introduction to Filaments
I’m Tom and today i’m going to give you a quick introduction to the common 3D printer filaments.
So what you might already know is that the filament is a 3D printer’s feedstock which it uses to build the things it makes. All filaments have in common that they are thermoplastics, which means that the filament softens and eventually melts when it is heated. As opposed to metals, which have a distinct melting temperature at which they go from solid to liquid, thermoplastics gradually soften and melt when they are heated up. Which, for 3D printing, means that you can control the viscosity of the plastic by picking a temperature at which the plastic is neither too liquid nor too tough. IIt also means that we can’t print metals with our filament-based printers.
And while you could theoretically print almost any thermoplastic, there are two that are really popular: One is PLA and the other is ABS.
So PLA is the most popular filament at the moment. It’s a polymer that is made from corn starch and at the same time is biodegradable, which means that it can be composted under the right circumstances. It’s so popular because, once you get your printer dialed in, it will give you repeatable results no matter what you’re trying to print. It also smells nice when printing – it’s kind of a mix between cotton candy and popcorn.
At the same time, it is fairly tolerant about what machine you print it on – PLA does not need a heated bed for sticking and easily prints onto unheated blue painter’s tape. If you have a heated bed, you can also print it onto plain glass, glue-stick- or hairspray-covered glass or Kapton tape. It’s a fairly stiff plastic and printed parts generally turn out fairly strong.
However, there are a couple of challenges when printing PLA: One of them is that PLA tends to absorb water from the air, so you’ll need to keep your filament spools in sealed containers when you’re not using them or bake them in the oven every now and then. The other is that PLA often doesn’t cool and harden fast enough when printing it. There’s an easy solution for that, though, and that is having a small fan blowing over the printed part while it is being printed. Many printers come with a fan pre-installed, so that’s already accounted for. The last downside to using PLA is that it really isn’t temperature-stable and will soften and deform at about 50°C. Now, i know that sounds like a lot, but just leaving a part in your car on a warm day can be enough to have it warping.
The other plastic, which is a bit more on the “traditional” side, is ABS. Usually, when someone mentions ABS for the first time, they’ll say that ABS is what LEGO are made of. And that’s true, but ABS is simply a very common plastic and is used in anything from coffee makers to flat screen TVs. When it comes to 3D printing, ABS is often used when the part needs to be tough or temperature-resistant. ABS has a bit of a wax-like feeling to it, and ínstead of snapping like PLA, it bends and deforms. It’s also not as stiff as PLA and much more temperature-resistant: It only softens at about 100°C, which is why parts for a 3D printer are usually printed with ABS and not with PLA.
Now, ABS can be a bit more challenging to print for one reason, and that is that ABS contracts quite a bit as it cools. Because of this, larger prints can warp and become unstuck from the bed or the individual layers of the print can peel apart and weaken the final part. It’s also practically impossible to print ABS without using a heated bed, but then again, most printers come with one as a standard option. When you have one, you can print ABS onto Kapton or PET tape or onto a layer of hairspray or glue stick.
So which plastic you choose to print will depend entirely on what you’re using the 3D printer for: i’m personally mostly printing in ABS because i use the parts in all sorts of contraptions where i need parts that won’t deform when they get a bit warm. If you’re going to print light-duty parts or complex artistic pieces or simply enjoy that feeling that your printer will be able to handle almost every part you print, then PLA is probably the better choice for you.
Now, the world of 3D printer filaments isn’t just PLA and ABS, there’s now a whole bunch of new and special-purpose plastics, like Taulman’s all-purpose nylon filaments, super-tough polycarbonate, wood-like laywood or even rubber-like filaments like Ninjaflex. For getting started, you should stick to PLA or ABS and once you’re confident with one of those you can move on to the newer materials. Also, buy your filament from suppliers that have a good reputation and don’t order no-name filament from ebay if you don’t exactly know what you’re getting into. Especially PLA has huge quality differences between the cheap and the good stuff.
So that’s it for now, as always, thanks for watching – if you’d like to see more of these kind of videos, consider subscribing to my channel.