Learning how to 3D print with PLA is one of the first things you should figure out how to do when you get your 3D printer. PLA is one of the easier filaments to get the hang of, but you still need to know what kind of settings and improvements you can make to get your 3D prints looking spectacular.
To 3D print PLA, you should use a printing temperature between 190-220°C and a bed temperature between 30-50°C for the best results. Your cooling fan should be at 100%, with a print speed of 40-60mm/s. Keep your PLA filament dry by storing it in an airtight container with desiccant when not in use.
This article is going to be a simple, yet in-depth guide on how to 3D print PLA filament just like the pros do, so stick around to see how it’s done and get your questions answered.
What is PLA Material for 3D Printing & What is it Made of?
PLA or Polylactic Acid is a plastic made from biodegradable natural resources like sugarcane, corn starch, and maize. It is the most commonly used filament in 3D printing due to being easy to print and requiring a relatively low temperature. PLA is non-toxic and environmentally friendly.
PLA is manufactured by a fermentation process in which sugar is broken down into one of its by-products called lactic acid. This component is then converted into polylactic acid or PLA.
When starting out with 3D printing, most people pick up PLA as their first filament to print with. In the early days, ABS used to be the most popular filament, but PLA has taken over that position since it has respectable strength, and is pretty easy to sand/smooth.
Simplicity and ease of use is PLA’s biggest selling points, along with the fact that it doesn’t need a heated bed or an enclosed build chamber for ideal results.
It also does not emit toxic fumes to a great extent, and post-processing can be easily done on PLA-printed parts. You can make all sorts of fantastic items with PLA plastic such as containers, vases, plant pots, handles, figures, statues, prototypes, and plenty more, all at a respectable price.
What Temperature Should You 3D Print PLA?
The recommended nozzle temperature for printing PLA falls in the range of 180°C-220°C. Similarly, the best bed temperature for PLA is somewhere between 30-50°C. The perfect nozzle and bed temperature ranges are usually provided by the manufacturer you buy your filament from.
Each PLA filament comes with its manufacturer’s recommended temperature settings. These are pre-determined temperature ranges that are tested to work best for the filament in question.
One HATCHBOX PLA user said that a nozzle temperature of 210°C worked great for their prints while another customer had preferred 215°C. Temperature settings depend on your environment and your 3D printer setup.
Let’s take a look at some top-rated PLA filaments and their recommended temperature ranges.
- Nozzle Temperature: 180°C – 220°C
- Bed Temperature: 55°C-70°C
- Nozzle Temperature: 190°C-220°C
- Bed Temperature: 55°C-65°C
- Nozzle Temperature: 205°C-225°C
- Bed Temperature: 30°C-60°C
How Fast Can You 3D Print PLA? Printing Speeds for PLA
For PLA, the best printing speed is somewhere between 40-60mm/s. You can also print as fast as 100mm/s because PLA easily flows out of the nozzle, but quality at this speed will definitely suffer. Fine-tuning your settings and using a Delta 3D printer can produce higher speeds with great results.
The general rule in 3D printing is that the slower you print, the better your prints will come out looking. The key here is not to go too slow nor too fast, but to balance your printing speed.
You can print PLA at 60mm/s and get fairly decent quality prints because this filament’s mechanical properties allow it to be extruded easily and at higher speeds without affecting part quality.
Does PLA Need a Fan? Can You Print PLA Without a Cooling Fan?
Yes, PLA requires a cooling fan throughout the printing process. Without appropriate cooling, PLA parts will become prone to stringing, oozing, and warping. People usually set the fan speed at 100% as it can improve the overall quality and lead to better bridging and overhangs.
When people compared their surface quality at different fan percentage settings, you can see clear improvements in the quality with a 100% cooling fan activated.
For the first few layers of your 3D print, you want to have the cooling fans off so those layers properly adhere to the build plate without warping or curling. Your slicer should do this by default, then automatically turn on the fans at subsequent layers.
What is a Good Wall Thickness for PLA?
A good wall thickness value for PLA is 2mm that balances strength and durability. For really strong PLA 3D prints, a wall thickness of 2.5-3mm can work very well, especially for functional prints that have constant weight applied to it. You usually do not want to go below a 1.2mm wall thickness for 3D prints.
Wall thickness determines how weak or strong your print is structurally. You may be able to successfully print models with a low wall thickness, but with handling and common impacts, you may find your model isn’t very durable.
It can also lead to more warping and print failures due to not having as good of a foundation as you require, but this mainly depends on the structure and orientation of the model.
Similarly, using a too high wall thickness value can take away flexibility from your model, possibly resulting in print failures so it’s good to strike a balance for your wall thickness settings.
I’d stick between a wall thickness range of 1.5mm-3mm in most cases. The best thing you can do though is to trial and error your own wall thickness to see how the strength of 3D prints change.
You can try printing the same object with increases of 0.5mm increments for wall thickness to see what works best for your specific project or model.
What Are Advantages of 3D Printing PLA?
- Exceptionally easy to use and boasts high printability – the reasons why beginners pick up PLA to start their 3D printing journey with.
- PLA comes in a wide range of colors, blends, and hybrids with other filaments
- Environment-friendly and does not emit toxic odors, being one of the safest thermoplastic filament out there.
- Cost-effective and can be bought for cheap.
- It has a relatively low printing temperature that makes it easy to print and with fewer failures.
- Produces parts with terrific surface detail and quality.
- Post-processing is painless with PLA, allowing you to sand, prime, and paint with low effort.
- Biodegradable and breaks down in years as compared to ABS that can naturally last for hundreds of years.
- Natural PLA is labelled as food safe.
- Has fairly decent stiffness, and strength.
- Does not require a heat bed or an enclosed print chamber to print successfully
What Are the Disadvantages of 3D Printing PLA?
- PLA has less flexibility compared to other filaments, and has been known to be brittle in some cases when not printed properly
- It has a fairly low heat resistance, meaning that the filament is likely to deform when exposed to higher temperatures.
- Can absorb moisture from the air, making it unsuitable to be printed in high humidity environments.
- Biodegrability is a disadvantage as well, since PLA parts are not the best option for long-lasting models.
- PLA is vulnerable to oozing and therefore requires cooling fans for most of the print job.
- Doesn’t have the best resistance to UV
Tip: Dial in your retraction settings to take care of stringing/oozing with PLA. Learn how to get the best retraction speed and length settings by checking out the article.
How to Improve PLA Prints
To improve PLA prints, you need to level your bed and set the correct nozzle distance. Reducing the print speed can lead to better results, and using a 0.1mm layer height for higher quality. Moreover, using a filament dryer to store PLA can significantly improve the material’s performance.
PLA may seem like an easy filament to print with, but 3D printing is still complex on its own and it’s pretty easy to end up with undesirable prints if you don’t know what you’re doing.
A good-looking 3D print makes sure your time and money was spent well. If you’re getting poor results, there are a handful of things you can tweak and adjust to start printing impressively.
The first thing to check is the print bed and examine it for any issues. A properly leveled bed eliminates several print problems right from the get-go.
Temperature also plays a key role in 3D printing. Using the right nozzle temperature for your filament drastically improves print quality and negates hassles such as stringing.
You want to use a temperature that is just about enough to soften the filament enough to extrude it nicely, rather than using a really high temperature for the best results.
While a heated bed is not necessary for PLA, if you run into adhesion issues, try increasing your bed temperature to a value between 30-60°C. You can also use blue painter’s tape to further enhance the adhesive property of your print bed.
Having a printing speed too high can lead to poor surface quality, usually due to vibrations in the printer’s frame from all the movements. You can minimize the lower quality by making sure to have a stable workstation and 3D printer frame.
Cura defaults to 50mm/s for the print speed, but you can try reducing your speed in 5mm/s increments and check for visual improvements. A lower print speed always equates to higher print quality.
Post-processing is a useful step to improve the quality of your 3D prints. As PLA is easy to post-process, you can remove small defects by sanding your part or by using a knife. You can also prime and paint your model to give it a great finished look.
All that being said, you cannot hope to print successfully when your filament is in bad condition. I highly recommend taking care of your PLA filament by storing it somewhere it can stay dry, such as a food dehydrator, or a specific filament dryer.
You can purchase a professional filament dryer solution like the SUNLU Upgraded Filament Dryer from Amazon. You can efficiently remove excess moisture from your filament in a matter of hours, giving you more success and better quality 3D prints.
It’s very easy to set up since the filament dryer is fully assembled. You also have the added benefit of drying during 3D printing, for a moisture-free experience.
How Do You Make PLA 3D Prints Smooth?
The best way to smooth PLA 3D prints is to sand the model with different grits of sandpaper. After sanding, you can either apply a polishing compound or use a primer spray paint to get rid of layer lines and enjoy a smooth finish. You can also use a brush-on epoxy resin called XTC-3D for impressive, glossy results.
Smoothing a PLA 3D print can have numerous advantages, such as making it possible to print at a higher layer height, and use more supports. All emerging imperfections would, later on, be eliminated by smoothing the PLA parts.
While people mostly use sandpaper to smooth their PLA parts along with a combination of the XTC-3D brush-on epoxy, you can also use a heat gun and run it along the surface of the print. This method isn’t recommended though, and there’s a risk to damage your model.
How to Get PLA to Stick to the Bed
Leveling the print bed first is the go-to method for getting PLA to stick to the bed. After leveling the bed and making sure it’s clean, you can use a bed adhesive like blue painter’s tape and increase the heat bed temperature to make your PLA prints adhere strongly to the bed. Using a raft also works well.
Although PLA does not require a heat bed as it is a low-temperature filament, you can still turn up the heating for the first few layers to help it stick to the bed. Make sure to turn off the fans for the initial layers, so the part has an easier time sticking to the bed.
Remember to stay within the manufacturer’s recommended range for the nozzle and bed temperature and not go overboard as PLA can get too soft.
You can also print slower for the first few layers. There’s a setting in Cura called “Initial Layer Speed.” Printing at about 50% of your Print Speed can greatly increase your chances to get PLA to stick to the bed.
If your PLA prints aren’t sticking to the bed, I’d definitely recommend using an adhesive for your bed. Blue painter’s tape seems to work well, but you can also use glue sticks, hair sprays, or any other sticky substance.
You can get specific build surfaces that are known to be good for filaments to adhere to like PEI sheets or a nicely cleaned borosilicate glass bed.
Types of PLA Filament
One of the best advantages of buying PLA is that it is available in a comprehensive array of blends and colors. There is now a PLA filament for every use-case, whether you’re looking to print something exotic, or a mechanical part that needs to have high resistance properties.
I’ve put together a list of the many different types of PLA filament. The following, therefore, can give you an insight into what can be accomplished with this terrific thermoplastic material.
- Silk PLA
- Glow-in-the-dark PLA
- Carbon Fiber PLA
- Sparkling Glitter PLA
- Wood PLA
- Fluorescent PLA
- Flexible PLA
- Conductive PLA
- High-Strength PLA
- High-Temperature PLA
- Metallic PLA (Gold, Copper, Magnetic Iron, Brass, Bronze)
- Translucent PLA
- Multi-Color PLA
- Polyester PLA
Is PLA Biodegradable?
Yes, PLA is biodegradable since it is made from renewable resources like corn and starch. Specific conditions are required for PLA to biodegrade, such as high humidity, a temperature above 50°C, and micro-organisms. A professional facility usually provides the controlled environment for biodegradation to happen.
PLA’s biodegradability lends it a positive reception from makers around the world, and perhaps, this is a major reason why it’s the most popular filament in FDM 3D printing.
That said, anything made out of PLA is most likely to endure a good number of years and won’t simply degrade away in everyday conditions, such as keeping a PLA model at room temperature won’t have any significant effect.
What Kind of Paint Do You Use on PLA 3D Prints?
To paint PLA 3D prints, the most common kind of paint to use are acrylic paints that can be applied by using an airbrush, a canned spray, or a simple brush. There are other types of paints such as lacquers, oils, and enamels as well, but beginners are recommended to start with acrylic paints as they easily come off with water.
It’s common practice to use a primer before painting a 3D printed model, as it can help prepare the surface of the part to be painted. Before all that, sanding and polishing are fully encouraged, since it makes the applied paint look even more gorgeous.
What Happens if You Print PLA Too Hot?
Printing PLA too hot can result in your layers being too soft for the next layer to have a good foundation. This can lead to your part deforming, bubbling, warping and other imperfections like stringing. In some cases, a slightly hot temperature can improve layer adhesion and strength.
If you print PLA at a bed temperature that’s too hot, you can experience elephant’s foot, which is when the bottom layers become soft and the weight of the layers above them push down, squishing the initial layers and making them spread out.
In the video below, Stefan from CNC Kitchen experiments what happens when you print PLA at higher temperatures. Be sure to give it a watch.
What Can Dissolve PLA?
PLA can be dissolved by using chemical agents such as ethyl acetate, tetrahydrofuran (THF), methyl ethyl ketone, and methylamine as well, though some are quite dangerous chemicals. Some claim you can use Sodium Hydroxide (NaOH) and a water solution to dissolve your PLA parts effectively.
These chemicals are known to react with PLA and end up dissolving it, but if you’re looking to clean your extruder head, I recommend using methyl ethyl ketone to wipe the surface and protect your extruder from damage.
You can also use caustic soda which is a mixture of sodium hydroxide and water to dissolve PLA support structures.
Another method would be using Dichloromethane (DCM) but that isn’t readily available to everyone and is costly as well. I recommend sticking to substances like ethyl acetate, and methylamine in water that’s known to work effectively.
Can You Drink Out of PLA?
Yes, you can drink out of a PLA object, but not repeatedly. There are small gaps in the layers where bacteria growth can occur. In addition, PLA is a low-temperature filament, and coffee or tea will definitely melt any cup or mug made out of PLA, so no hot drinks either.
PLA is generally known to be food-safe, but things aren’t as simple as that. Your 3D object can be easily contaminated during any part of the 3D printing process, making the object unfit to be used for eating or drinking.
In addition, 3D printed models aren’t water-tight and there are small gaps in the layers that can serve as breeding grounds for bacteria and other micro-organisms. Your PLA-made mug can be suitable to drink from two or three times, but not any more than that.
It’s recommended to use a dedicated food-safe PLA filament that comes FDA approved on its material safety data sheet (MSDS). You can also use a food-safe stainless steel hot end to further prevent contamination of your 3D printed model.
It’s a good idea to use a food-safe epoxy sealant to fill in any gaps in 3D printed parts, allowing for a smooth and safe surface for food or drinks.
Is PLA Toxic to Humans?
PLA is a non-toxic plastic that isn’t harmful to humans in standard form, but when heated to high temperatures, it emits fumes with ultrafine particles that are known to be respiratory irritants. Lower temperature PLAs are usually the safer option. Make sure to 3D print PLA in well-ventilated areas.
PLA is one of the safest filaments out there that you can use to 3D print. Being sourced from natural substances, it is known to be fairly benign or harmless. Some people have complained of a sore throat or even headaches when 3D printing PLA in the same room.
It’s important to keep yourself safe by 3D printing in a separate, well-ventilated room that people aren’t regularly occupying. There aren’t too many extensive studies to my knowledge on long-term effects of 3D printing, but tests measuring the air quality after printing have been done.
PLA doesn’t emit the most harmful chemicals as compared to ABS, or Nylon for example, but some emissions aren’t ideal for humans to ingest. Manufacturers of PLA use various additives and dyes to give it specific properties, so keep this in mind.
In addition, microbes and bacteria can also grow in the tiny cracks and gaps found in 3D printed objects. It’s recommended not to use them frequently for handling food to avoid harmful pathogens.
Does PLA Dissolve in Water?
No, PLA cannot dissolve in water, but when submerged in it for a long period of time, the filament can slowly start to absorb water. Without meeting certain conditions such as a high water temperature, and UV light exposure, PLA will keep it’s structural shape and properties just fine.
Can PLA Filament Be Too Dry?
Yes, drying PLA for too long can have adverse effects on quality and strength. If there are heat-sensitive chemicals present in the filament, excessive drying can remove them. It’s better to dry the filament once to remove the moisture and then store it in a dry box to keep it at its best quality.