Among all the 3D printing materials around the world, the most commonly used filaments are PLA and ABS. Both are thermoplastics and malleable when exposed to high temperatures. Both are very affordable. And even if you didn’t have a 3D printer at home, you can probably find them being offered by any 3D printing service online. But that doesn’t mean they’re interchangeable. Which is why we decided to answer one of the most common questions beginners have about 3D Printing: ABS vs PLA – which one is best for my project?
3D Printing ABS vs PLA: Overview
We’ve already mentioned several similarities between ABS and PLA. They’re both thermoplastics, malleable when heated, and are budget-friendly. But what exactly is the composition and properties of each material?
ABS is short for acrylonitrile butadiene styrene which is an oil-based thermoplastic that has been around for quite a while. It’s a material that is commonly used in the injection molding industry. In fact, most people have come across this material before. They’re what Legos are made of!
This material is tough, durable, and lightweight. It retains color very well. It has a high heat and impact resistance. It is also resistant to water and chemicals. ABS becomes malleable when heated to 220 degrees C (430 F). And it produces models with a smooth finish.
PLA is short polylactic acid is a fully-biodegradable thermoplastic that is made from organic material such as corn starch or sugar cane. Aside from 3D printing, this material is also used to create food containers, disposable tableware, and medical implants. Like ABS, it has a low price point which is one of the reasons why it is so popular.
PLA is easy to use because it doesn’t require a high temperature to become malleable. In addition, it has low warping and comes in a variety of colors. This material has high strength and stiffness. However, it does have a low melting point. Plus, it is brittle which means it has low impact resistance. It also has low chemical resistance.
3D Printing ABS vs PLA: Comparison
Just reading the overview above should give you some insight on how these two 3D printing materials differ from each other. That being said, it’s always important to go into the nitty-gritty to ensure that you’re making the right choice for your project.
The cost of material is one of the most important things you need to first consider when it comes to 3D printing. ABS vs PLA prices aren’t so different from each other.
According to Amazon prices, you can get 1kg of ABS for $USD 21.99 while PLA costs $USD 22.99. A dollar difference isn’t a big enough factor to sway your decision one way or another. Moving on.
- Thermal Properties
Obviously, both of these thermoplastics melt. But they have different printing temperatures. ABS requires at least 210°C in order to be used for printing. Moreover, it also requires a heated print bed.
PLA, on the other hand, has a printing temperature of 180-230°C. This is one reason why this material is easier to print with. It doesn’t require a lot of heat. It also doesn’t need a heated print bed.
Their levels of heat resistance differ as well. Because ABS has a glass transition temperature of 105°C (the amount of heat it takes before it transforms from hard to viscous and rubbery), it can withstand high temperatures.
PLA, on the other hand, has a glass transition temperature of 57°C which means that its structural integrity will falter when it is exposed to high heat. In simpler terms, an item made out of PLA will begin to deform, especially if it is under stress when it is exposed to high temperatures.
- Strength and Flexibility
Both ABS and PLA are great materials for prototyping. However, ABS has better ductility in comparison. It is not brittle like PLA; it has greater flexural strength (bending strength) which means that it will take longer to break. It is stiff and highly impact-resistant. It is also more water-resistant compared to PLA. Just think of how strong and durable your Legos are.
PLA has good tensile strength (surface hardness), similar to that of ABS. However, it is more rigid and fragile. It can break more easily because it isn’t flexible enough to bend. ABS, on the other hand, will distort and bend first before breaking.
Take note that PLA and ABS both degrade when exposed to moisture and UV rays.
- Surface Finishing and Post-processing
Any object printed using an FDM printer will have visible print layers. Generally, PLA models are semi-transparent which gives them a glossy finish while ABS models have a matte finish.
Both ABS and PLA models can undergo post-processing (i.e. cutting, filing, sanding, painting, etc.) to make the layer lines disappear. However, PLA will require a little more care. It may also require several attempts before you can achieve your desired result. On the other hand, it is generally much easier to achieve a smoother surface with ABS using solvents such as acetone.
One of the biggest advantages of using PLA is that it is biodegradable. Less waste produced which makes it environmentally-friendly. ABS, on the other hand, is not. Though, you can recycle it.
ABS and PLA are both hygroscopic. This means that they absorb moisture from the air. This is not a good thing. The more moisture they absorb, the poorer the quality of the print will be. What does this mean? Both materials cannot be exposed to air for long periods of time; they need to be stored in airtight containers and put aside in a cool, dry place.
PLA vs ABS 3D Printing: Which Is Better?
In the PLA vs ABS 3D printing debate, there’s no clear winner. Both can be used by desktop FDM 3D printers and are quite similar when it comes to cost. Ultimately, the choice of material will be determined by the type of project you are undertaking. Below we give examples of when you can use PLA and when to opt for ABS.
When to use ABS 3D Printing?
The superior mechanical properties of ABS makes it more suitable for applications that require strength, high durability, machinability, and ductility. This is why it is often used for engineering and manufacturing purposes. It is also ideal for models that will be exposed to heat, dropped, or even just frequently handled.
Some examples of items that require the properties of ABS are high-wear toys, automotive trim components, phone cases, tool handles, and electrical enclosures. Overall, when compared to PLA, ABS is more suited for end-use applications.
When to use PLA 3D Printing?
PLA is an even more popular choice of 3D printing material than ABS. And it’s not just because it’s biodegradable (though that’s a reason too). PLA is the recommended material for beginners because it’s so easy to print with.
This material is also recommended for printing models with fine details. It produces the best finishing and is available in more colors. Its mechanical properties are similar to ABS, but it isn’t as durable. This means that it’s not ideal for items that are frequently handled or dropped. Moreover, because PLA does not have great flexural strength, it is more suitable for prototyping where form is more important than function. PLA also can’t withstand high temperatures which means it is not suitable for outdoor items.
The good news is that PLA doesn’t emit unpleasant fumes which makes it perfect for use in offices and schools. If you want to print with PLA, some prints you can achieve using this material contain food containers, prototype parts, plastic bags, cutlery, and low-wear toys.