PLA is very probably the most popular 3d printing filament around. There’s a good reason for that popularity. Its one of the easiest materials to work with, giving good results within a wider range of variables than the majority of other filaments on the market.
PLA properties mean its forgiving to print with and has excellent finish quality.
In this article, we’re going to take a closer look at PLA and show you how to get the best results possible when using it on your print jobs.
What is PLA material?
You might be wondering what exactly is PLA filament made from? Well its full term is Poly-Lactic Acid and it is a thermoplastic polymer. Because it is derived from natural sources like corn and sometimes sugarcane, PLA is sometimes referred to a bioplastic. The majority of other thermoplastics are distilled from non-renewable resources like petroleum.
In addition, because it is a natural product, it is also biodegradable. This means that when discarded into a composting system, PLA will naturally break down into its constituent parts in about three to six months. Compare this to other thermoplastics which could take up to one thousand years to biodegrade.
What are the best applications for using PLA?
As PLA is so versatile, it's a great starting filament to use for the majority of 3D prints. Be weary though, due it being commonplace in the market - there is a lot of poor quality PLA around. People try this, get frustrated that it's weak and brittle and move onto other materials to 3D Print.
Our advice is to use high quality PLA. Don't just write it off as being not strong enough for the variety of prints. You'll be amazed at the difference. There's no need to move onto 'stronger' filaments like ABS, PETG or others until your prints get more advanced.
Typically print with PLA until you find you have a reason to experiment with other materials. When you want to print more exciting/usable products you can experiment with flexible materials.
Why print with PLA?
Here's why we love PLA 3D printer filament so much:
- It's easy and forgiving to print. Get good quality PLA and it'll flow nicely and won't warp.
- The finish detail is usually very neat. It isn't prone to stringing or blobbing.
- Post print finishing is straight forward. It's easy to sand, drill or cut after printing.
- It can be surprisingly strong (see the video below).
- PLA can be pigmented easily, so you'll usually find colour selections better and vivid.
- Its doesn't smell bad when printing (not that you should be smelling it, always print in well ventilated areas).
- You don't need to feel bad throwing it out, because eventually it'll biodegrade. Its also non-toxic and all natural ingredients. Well, ours is anyway.
- PLA print temperature is lower than most other filaments.
Pure PLA cannot be acetone smoothed, but it can be finished easily like this Bronze Benchy.
Is PLA filament food safe?
When not 3D printed, yes. If you’re new to 3d printing, it’s likely that you’ve already encountered PLA around your home. PLA is used to make many common objects, including food containers, disposable tableware and garbage bags.
However, 3D printing in PLA will not create food safe containers, because 3d printing can cause many tiny gaps and cavities in your prints that will harbor moisture and food residue. After a few washes, this will turn into mold and you won't be able to keep it clean.
Even though PLA is biodegradable it is still a strong and durable material. You will find PLA to be harder than other common thermoplastics like ABS. However, its lower tensile strength tends to make it more brittle PLA.
What is PLA melting point?
It should be noted that PLA melting temp is relatively low temperature, in the neighborhood of 170C upwards which makes it a poorer choice for objects that will be used in a higher temperature application.
Objects that are 3D printed with PLA will hold up fine when used at room temperatures in a normal environment.
3D Printing with PLA
Now that you know what PLA is and you have a general understanding of its strengths and weaknesses, let’s take a look at some of the things that you can do to get the most out of using PLA as a print material.
In this regard, we’re going to look at three critical areas that can affect the success of any 3d printing job – temperature, adhesion and material storage.
In any print job, it’s very important that you get the printing temperature just right if you want a good run. Printing with PLA is no exception to this rule. It's worth noting that higher quality PLAs print at lower temperatures, due to the purity of the resin and lack of contaminants.
PLA benefits from relatively low shrinkage, hence the low-to-no warp. While the PLA shrinkage varies from manufacture to manufacture it is usually within the 2-5% range. You're best printing a model that's an known length, with both horizontal, vertical and perpendicular holes in that you can measure it's length, and dimensions of the holes after printing to compare.
What temperature to print PLA?
In general, PLA filament settings have an optimal printing PLA temperature range from about 185C to about 205C. If you’re using 1.75mm as opposed to thicker 2.85mm (or 3.00mm) your optimal print will be closer to the lower end of this PLA filament temperature range.
If you’re using 2.85mm filament, you might want to go closer to the higher end of the temperature range to compensate for the increased thickness of the material.
With any material, and PLA extruder temperature can differ (+/-10%) depending on your machine. It may be wise to independently measure the temp of your extruder nozzle to accurately dial in the extrusion heat.
Want to print PLA filament clear? Check out our printing how to print clear filaments, clearer article here.
In any event, no matter what PLA filament temperature you start with, you do want to adjust that temperature slightly upwards or downwards depending on the environment of the room you are printing in and the initial print conditions that you observe.
In general, it’s a good idea to start PLA printing temperature at about 180C and note how the material is being extruded, as well as the quality of the print layers being produced. That's usually the best temp for PLA settings. If you note problems with the material, simply adjust the temperature up or down in 5C increments until the problem is no longer noticeable.
Please note that due to the high quality of our PLA you'll want to typically print at lower temperatures than others available. Finding the best PLA temperature can be a little trial and error but is nearly always nearer the lower end of the spectrum for higher end filaments.
Your print temperature is probably too high if you notice that strings of material are occurring as your printer is moving between different parts of the print job. This “stringing” happens because the PLA loses too much viscosity due to being too hot. As a result, the material leaks out of the print nozzle as it moves.
Your print temperature is probably too low if you notice that the PLA is having trouble adhering to the print surface or to previous layers. Temperature is also likely the cause of problems in the surface of the printed object like gaps, holes and missing layers.
However it's worth noting in our experience, 90% of problems printing with PLA is that it's simply being printed too hot. So if in doubt on your 3D printer settings for PLA, turn it down.
This is an indication that the PLA is under extruding because of a higher material viscosity caused by a PLA 3D printing temperature that is too low. In either case, dialing in the correct print temperature will increase the chances that you’ll end up with an object that is both useful and beautiful.
Be careful you don't boil your PLA. This sounds odd, but it's easy to print good quality PLA too hot. If you're doing high detail or bridges, you want to control your PLA print temp with fans, to prevent sagging or loss of detail to 'melting' style effects.
When it comes to print speed, every printer is different and optimum settings will depend on what type of printer you’re using. However, printing PLA is usually good at any speed between 30mm to 90mm/sec. For higher quality end results, a lower printer speed is more likely to get you the finished product that you want. As with temperature, the best speed for the object that you’re printing will need to be dialed in.
Getting PLA to stick can be a combination of correct distance from the bed, bed surface material and 1st layer fan speed (off).
Getting your print material to adhere to your print surface is key to a successful print run. One of the things that make high quality PLA one of the easier materials to print with is that it somewhat easily adheres to a wide variety of surfaces with a minimum of fuss.
Printing PLA without a heated bed is easily done - although to aid first layer adhesion we do recommend a heated bed between 40-50C.
Problems with your PLA filament not sticking? Take a look at our article on build plate surfaces and adhesion to get an idea of what PLA build surfaces might work best for you.
One additional thing should be noted. PLA doesn't require a heated bed to print it as it's low warp, but you might want to use one as it can make those first few layers adhesion easier.
If your PLA does warp, you might want to take a look at our article “Warping – Why It Happens and How to Prevent It” which can be found here.
It's always best to store your filament in our metallic sealable bags between uses
PLA, like a number of other thermoplastics is hygroscopic. This means that, over time, it naturally absorbs water from the air that surrounds it. When water builds up it PLA, it tends to break down or alter the molecular chains that hold the PLA together. When you print with PLA that has absorbed water, you will find that it is harder to get layers to bind together and those that do bind together tend to be distorted.
Is your PLA filament brittle or snapping? That's likely caused by (assuming it was good filament to start with) it having absorbed moisture.
The solution to this problem is in proper storage of your PLA when you’re not printing. Here at rigid.ink, this is the reason we provide metallic, sealable bags, along with desiccants, with every order we ship. It makes no sense to sell our customers the highest quality thermoplastics available and not give them the best means to protect those materials when they are not being used.
To get a better idea on just how much difference good quality PLA is over cheap PLA, check out Tom Sanladerer's video here:
It’s our goal to make sure that your print jobs are a success the first time, every time you print. When what you print is less than successful you not only waste material, you also waste time. Low cost filament seems like a bargain, but it’s not. Yes, you don’t pay as much upfront for your printing material. However, when design after design is ruined because of imperfections in the filament, the cost of buying replacement filament begins to add up.
As Tom says, our PLA printing filament is the best you’ll find. Don't believe us? Just check out our PLA filament reviews. We carefully manufacture our filament PLA 1.75mm and 2.85mm to super-tight tolerances of just +/-0.03mm either side of the diameter you purchase.
This means that when you use our PLA you save time and money and get a successful print run, time after time.
We also offer FREE 10m samples to test, as well as filament 1KG & 3KG rolls shipped from here in the UK.