3D printing is one of the more amazing technologies that has emerged in recent years. We’ve been able to make the sci-fi dream of creating objects out of thin air a reality, and 3D printing has gained popularity with manufacturers and home crafters alike.
But one of the first questions you’ll need to answer when you start looking into 3D printing is what material you should use.
PLA is a very popular choice for 3D printing, and for good reason. Read on to learn more about this material and why PLA printing is such a fantastic option, both for you and for our planet.
What Is PLA?
Polylactic acid, better known as PLA, is a form of biodegradable plastic that is a popular material in 3D printing. Most plastics are made from petroleum, the same non-renewable oil that powers our cars. However, unlike these materials, PLA is made from vegetable material, making it a much more eco-friendly option.
As we’ll discuss more in a moment, PLA is popular as a material for the fused deposition modeling style of 3D printing. Despite the fact that it’s made using different raw materials, PLA can be manufactured using the same equipment and processes as traditional petrochemical plastics. This makes it cheap to produce and affordable for consumers.
How It’s Made
PLA starts its life as a plant – most commonly corn, sugarcane, beets, or a similarly starchy plant. Manufacturers have to use plant materials that have a high starch content because where there’s starch, there’s sugar. They then ferment that sugar, meaning they allow yeast cells to eat the natural sugar in the plants and turn it into alcohol and carbon dioxide.
Another byproduct of the fermentation process is lactic acid, a substance also naturally found in yogurt, our digestive tracts, and even our blood. Manufacturers can turn this lactic acid into a polymer, which gives PLA both its name and its remarkable qualities. Once the plastic is formed, manufacturers can color it a wide variety of hues and extrude it into whatever shape is needed, including nylon 3D filament.
Common Uses
As we mentioned, one of the most popular uses for PLA is as the one of the best 3D printer filament types. In particular, it’s a common material choice for home crafters using small-scale 3D printers. This is due in part to the fact that it’s affordable and in part because it works with the FDM 3D printing approach.
Fused deposition modeling, or FDM, is the most common technique for home 3D printers. These machines extrude filaments out through a heated nozzle, which melts the material before laying it down on the previous layer of materials. The low melting point of PLA makes it an ideal material for this process.
You can also find PLA in all sorts of materials that surround you every day. Many medical devices, including temporary plastic pins, screws, plates, and rods are made with PLA. Many types of plastic film and bottles also use this material.
Types of PLA
You might be surprised to learn that all PLA isn’t made the same. In fact, there are four different types of PLA: racemic PLLA, regular PLLA, PDLA, and PDLLA. The primary difference among all these different types of PLA is that they have slightly different chemical structures that give them somewhat different properties.
PLA+
Another subgroup of the PLA family is PLA+, a specialized form of plastic that’s designed to have enhanced properties. Oftentimes, PLA+ is aimed at addressing one of the weaknesses PLA can have such as a low melting point, low stiffness rating, high moisture absorption, and so on. This helps manufacturers make PLA work for a wider variety of different applications.
It’s important to note that there is no single formula for PLA+, so the properties of different versions of this material can change. In fact, manufacturers can simply choose premium ingredients for their PLA and call the new material PLA+. Always check the specifications on your PLA+ before you begin planning any projects with it.
Environmental Benefits
One of the biggest advantages PLA brings to the table is that it can offer a number of environmental benefits. Traditional plastics are made using processes that damage our environment and use up non-renewable resources. They are also non-biodegradable, meaning that any piece of petrochemical plastic you’ve ever touched is still in existence somewhere in the world.
Unlike traditional plastics, PLA comes from sustainable sources and is biodegradable. It will break down when exposed to sunlight, as well as by a couple of other chemical processes. And because it comes from fast-growing plants like corn, beets, and sugarcane, PLA is much more sustainable in the long run.
Thermal Properties
The thermal properties of PLA are something of a double-edged sword when it comes to pros and cons. On one hand, PLA has very low heat resistance, making it easy to melt into a liquid form. This is great news for people who want to use it for 3D filament types or for molding applications.
However, the fact that PLA will melt at such low temperatures (around 266 F) makes it unsuitable for some uses. For instance, the average cup of coffee or tea is served somewhere between 160 and 185 F. While this won’t be enough to reduce your PLA cup to a liquid, it can cause the material to soften and deform.
Food Safety
While PLA should not be used with hot food and drinks, this doesn’t mean it’s entirely unsafe for food use. In fact, one of the big benefits of PLA is that it is safe for use with food and drinks. It can be a great option for making drinking glasses, water bottles, sandwich containers, and snack containers.
PLA’s food-safe qualities are another reason home crafters love it so much. You may want to create a fun serving tray or customized water cup for a loved one or a customer. PLA will be fine to use for these applications, unlike other 3D printer plastic types that could shed microplastics or leech dangerous chemicals into the food.
Finishing Benefits
While 3D printing is something of a miracle technology, it does have some minor downsides. Among them is that 3D printed objects tend to have a rough, ridged finish because of the way the printer lays down layers to create the object. Some materials make it very difficult to get rid of this and create a smooth, finished item.
PLA is the best filament for anyone looking to create a smooth finish on their 3D printed objects. Because it’s relatively soft, it sands easily so you can get rid of the rough layer edges. And because the best PLA filament comes in so many different colors, it's the best filament you can choose for your projects.
PLA Disadvantages
Like any material, PLA has its downsides, many of which will depend on the function of your printed object. As we’ve mentioned, PLA has a low melting point that makes it unsuitable for any high-temperature applications. Even sitting outside in the summer heat can sometimes be enough to soften PLA and cause it to deform.
PLA can also be more flexible than some other types of 3D printing materials. While this isn’t a problem if you plan to use it to make sandwich containers, it can be an issue if you’re wanting to build, for instance, a tablet tripod. However, many varieties of PLA+ are designed to address these weaknesses and make PLA more widely usable.
PLA in the Future
For people with an eye towards the future, PLA is likely to be a leading force in production technology. Because it is so sustainable and environmentally friendly, it provides a fantastic alternative to the destructive plastics we’ve used in the past. And technologies like PLA+ expand the potential applications of this material.
While PLA is biodegradable, it does require some special treatment to break down properly. We need to set up measures to ensure that PLA products get the after-use treatment they need, rather than dumping them in a landfill. This appropriate treatment will help us keep our planet beautiful and healthy for many more centuries to come.
Learn More About PLA Printing
PLA is a fantastic material to work with for a variety of reasons. It’s affordable, sustainable, eco-friendly, and easy to finish. It’s popular among home crafters, and it has the potential to revolutionize how we approach plastics worldwide in the coming decades.
If you’d like to learn more about PLA printing, check out the rest of our site at 3DF Filaments.