Feb. 28, 2013
PLA 3D printing filament is a wonderful, easy-to-use, 3D printing material. It is a renewable and biodegradable resource. It is non-toxic and has a pleasant smell when printing. PLA 3D printing filament comes in a wide range of colors and because of its thermal characteristics, is particularly easy to get great prints with. Read on to discover the best practices for 3D printing with PLA 3D printing filament and get the best PLA 3D printed parts possible!
PLA or Polylactic acid is a thermoplastic polyester. It is commonly derived from renewable resources, such as corn starch, tapioca roots or sugarcane. One of the most attractive things about PLA plastic is that it is industrially compostable, which means it can be broken down back into its base elements through industrial means, and not through a ten thousand year lifespan. It is important to point out that although PLA is compostable it is very robust when used in any normal application such as a 3D printed jig or a manufacturing prototype. In that respect, you can think of it as being similar to iron. If you were to expose it to continuous moisture or leave it outside, it would "rust" and become brittle and unusable in short order. But if you had it in your home you would expect it to last nearly indefinitely.
PLA plastic is used in many industries from food packaging to biodegradable medical implants such as sutures, tissue screws, and tacks. PLA comes in a number of grades; scientific, medical, food safe, and then to the type of PLA used in consumer 3D printing. PLA's natural melting temperature is around 80°C but it is mixed with other plastics to make it suitable for 3D printing.
If you have printed with ABS filament, you will find PLA filament to be tougher, wear more slowly, and be easier to get a nice flat part with. PLA is less thermally contractive and much easier to print big parts with. The thing to consider is that being stiffer and harder also means that it is more brittle. If the part you're printing will be used where it might receive a lot of banging or sharp collisions, PLA may not be the best material.
The other important consideration when printing parts with PLA filament is knowing what sorts of temperatures the part will be subjected to. PLA plastic becomes soft at 70°C - 80°C and will deform if used in environments that remain above those temperatures for any prolonged time. This is why you should use ABS or PETG filament at a minimum when you have a design that will be exposed to heat, even as little as the heat inside a car on a summer day. At MatterHackers we generally use PLA filament for all our educational models, test-pieces, and quick-turnaround prototypes, as they aren't going to face any stressful scenarios, they just need to look good.
The first layer is the most important part of any print - it sets the foundation that the entire print builds on. You can check out the in-depth article on how to get a perfect first layer here, but below are the few things you need to do to get the first layer to stick well.
Below is a video from MatterHackers' 3D Printing Essentials series that will help guide you in the right direction for getting a stellar first layer. In this video, we'll walk you through the steps mentioned above in detail so you can succeed when 3D printing with PLA filament.
When you have a temperature controlled bed, printing directly on glass can be a great option. The recommended bed temperature for PLA is 65°C.
When you can get it working well, glass is a fantastic way to print PLA. It's the only way to have a shiny bottom layer and one of the easiest ways to have a perfectly flat surface.
With so many different 3D printer options available, it makes sense that there are a lot of different build surfaces that come stock on various machines. As 3D printing technology has grown, so have the options for bed surface upgrades. While it's not always necessary to upgrade your printer with a new build surface just to print with PLA 3D printing filament, it does have its benefits: it will more than likely enhance your 3D printing experience and also open the door for you to start using other 3D printing materials to expand the projects you are working on. For 3D printing with PLA filament, we recommend using these build surface upgrades:
3D printer build surface upgrades come in many sizes to fit a variety of 3D printers. If you can't find a build surface size that fits your 3D printer, you can use blue painter's tape to line your 3D printer's bed. We recommend taking these steps to succed with using PLA 3D printing filament on blue painter's tape:
In addition to build surface upgrades, there are also a wide variety of 3D printer adhesives that you can apply to your 3D printer's bed to get a great first layer. These adhesives are specifically developed for the 3D printing industry. Here are the best 3D printer adhesives that you can use to get the best first layer for PLA filament:
Most 3D printer bed adhesives have the same instructions for use: apply a thin layer to the build surface where your actively 3D printing. Then, wait for your part to cool before removing - waiting for your 3D printed part to cool makes it much easier to remove, and certain adhesives will sometimes even "pop" the part of the bed once cooled.
There are always new and exciting methods for bed adhesion being developed, so it's important to have a good grasp on what each method is best used for. You can check out our 3D Printing Essentials article about bed surfaces to fully understand the pros and cons of every bed surface you might come across while 3D printing.
When working with a new roll of PLA 3D printing filament for the first time, we generally like to start out printing at about 205°C and then adjust the temperature up or down by 5 degree increments until we get the quality of the print and the strength of the part to be in good balance with each other.
You will see more strings between the separate parts of your print and you may notice that the extruder leaks out a little bit of plastic while moving between separate areas of the print. If this happens you should try to incrementally lower the temperature by 5 degrees until the stringing is brought under control without compromising strength. If you just can't seem to get the stringing to stop, you might want to consider adjusting your retraction settings to increase retraction in increments of 0.5mm or so.
You will either see that the filament is not sticking to the previous layer and you are getting a rough surface (like the picture below), or you will get a part that is not strong and can be pulled apart easily. In either case, you should increase the temperature by 5 degrees and try again until you get good line segments on every layer and have a strong part when done printing.
When switching between two PLA spools and colors:
There are a few key things to check when your prints aren't working. But before we look at solutions we need to have a brief description of your symptoms.
"I can't get the first layer to stick."
"The part has bad internal layers and top surfaces."
"The outside edges of my parts have lots of little bumps on them."
"Tall sections of my prints look melted or squished together."
"My printer will not put out any material."
Thank you for reading How To Succeed When Printing In PLA.
If you have any comments or contributions, please drop us an email or give us a call. We are always looking for tips, and best practices - and would love to hear from you. Feel free to reach out with any specific questions on the MatterHackers Forum.
Happy Printing! - MatterHackers
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