If you’ve been 3D printing your favorite action figures, machine parts, or board games for playing with your friends and family, you’ve probably noticed how fun it is to be able to turn your imagination into reality.
PLA is the filament most commonly used in the printing process, and we bet this filament is no stranger to you.
While PLA holds plenty of benefits compared to other types of filaments, sometimes it can cause minor issues to your prints. A couple of issues that most people complain about are the formation of bumps and rough edges on their prints.
As a 3D printing enthusiast, you would always want to have the perfect print quality every time, and thankfully, it is possible!
Since PLA is a soluble filament, dissolving it in a suitable solvent will result in flawless prints. Read on this guide to learn how to dissolve PLA.
What To Consider Before Dissolving PLA?
How easily a PLA filament dissolves depends on several factors. Two of those factors that should be considered are the quality and thickness of the filament.
It is recommended you purchase a high-quality filament having the appropriate thickness before you proceed with the experiment. You should consider the factors not only for the experiment but also in general for getting the perfect results.
What Dissolves PLA And How To Do it?
Since PLA is a soluble filament, it is possible to dissolve it in suitable chemical solvents. While you may think of some solvents being harmful to health, there are also safe options.
The solvent for PLA dissolving you choose greatly depends on personal preference. You can consider the chemical properties of the solvent, its price, and availability.
When you use a PLA solvent correctly and follow the precautions, you can minimize the risks of hazards.
Here is a list of the solvents commonly used for dissolving PLA.
- Ethyl acetate
- Propylene carbonate
- Methylene chloride
- Caustic soda (sodium hydroxide)
1. Ethyl Acetate
Ethyl acetate is a colorless liquid commonly used in paints, varnishes, and perfumes. It is formed by reacting ethanol with acetic acid. Although this chemical delivers a sweet smell that resembles that of pear drops, it is actually a hazard.
When inhaled in high concentrations, the chemical has the potential of causing dizziness and damaging the lungs.
Also, frequent contact with the skin can cause dryness and irritation. It is recommended you take precautions every time you work with ethyl acetate.
Ethyl acetate can be used for smoothing the surface of 3D printed models and also removing support structures.
Before you start working with ethyl acetate, make sure to wear a safety mask and goggles. It is also recommended you work in a well-ventilated area.
Ethyl acetate is also flammable, so you should always keep it in a safe place away from heat and other chemicals.
Acetone is also a colorless liquid used in paint and nail polish remover and also in the manufacturing of plastic. The chemical is also made in the body during the breakdown of fat.
Small amounts of acetone in the body aren’t a problem, as the liver converts them into harmless chemicals.
While inhaling moderate levels of acetone for a short period of time can result in headaches, high levels can lead to vomiting and even coma.
Acetone isn’t one of the effective polylactic acid solvents because it can’t dissolve the filament completely. It does, however, modify the other components present in the filament.
The modification takes several hours and that leads to a softer and sticker filament. It is recommended to use small amounts of acetone at first.
Acetone is a highly flammable liquid that can generate dense smoke when it comes into contact with an ignition source, such as spark-producing equipment.
It is recommended you wear a safety mask and nitrile gloves while working with acetone. Also, make sure you handle the chemical in a well-ventilated area.
3. Propylene Carbonate
Propylene carbonate is a colorless and odorless liquid derived from glycol. It is mainly used in the formulation of makeup and skin cleansing products.
Although propylene carbonate doesn’t possess any serious health hazards, it is worth noting that the chemical is flammable.
Since propylene carbonate is flammable, make sure to store it a place away from ignition sources.
4. Methylene Chloride
Methylene chloride is a colorless and odorless liquid having a sweet smell. It is widely used in the manufacturing of paint removers, pharmaceutics, and metal degreasers.
When inhaled, methylene chloride can depress the central nervous system, and when it comes into frequent contact with the skin and eyes, it can lead to irritation. The chemical is also regarded as carcinogenic.
Compared to most solvents, methylene chloride readily dissolves PLA. However, it should be your last resort because of the potential hazards.
Always wear a safety mask, goggles, and PPE while handling methylene chloride. It is also recommended you work in a well-ventilated area.
Pyridine is a weakly alkaline liquid that emits a fish-like smell. It is commonly used in medicines, food flavorings, and adhesives.
Pyridine is a highly flammable chemical. It can also have serious effects on health, including dizziness, abdominal pain, and coma.
Since pyridine is highly flammable, it is recommended you work with it in an area away from ignition sources.
Also make sure to wear protective clothing, mask, and gloves while handling the chemical. In case it comes into contact with the skin, wash the area thoroughly.
Tetrahydrofuran is a colorless liquid having a low viscosity. It is used in the manufacturing of adhesives, coatings, and fibers.
Tetrahydrofuran is regarded as a dangerous chemical. When inhaled, the effects of tetrahydrofuran include shortness of breath, headache, and unconsciousness.
Additionally, its low flash point causes the chemical to ignite quickly when exposed to ignition sources.
Although tetrahydrofuran effectively dissolves PLA, it needs very careful handling.
Always make sure to wear protective clothing, mask, and gloves while working with tetrahydrofuran. Make sure not to inhale the chemical under any conditions. You should also work in a well-ventilated area.
7. Caustic Soda (Sodium Hydroxide)
Caustic soda or sodium hydroxide is a white solid compound used in the manufacturing of soap and detergents.
It is also a hazardous substance that can cause severe damage to any tissues it comes into contact with. It can burn the skin, irritate the eyes, and if inhaled, cause pneumonitis.
Despite the hazards, caustic soda is proven to be effective for dissolving PLA. Experts recommend dissolving 120 grams of causing soda in 1 liter of water before dipping PLA.
Before dipping PLA into the solution, make sure to wear safety goggles and special gloves. Also, the containers for the solution and caustic soda itself should meet high safety standards.
Smoothing PLA Without Using Solvents
If you’re worried about the risks the above solvents possess, you can opt for solvent-free alternatives!
1. Use The Same Build Material And Support Material In 3D Printing
If you use the same filament for both the build and support material, there’s a high chance of achieving better results. If you need to smooth the filament, you can use sandpaper or X-Acto knife.
2. Use Tools For Welding PLA Surfaces
Another alternative solution to the use of chemicals is to use tools for welding PLA surfaces.
3. Spray Sandable Primer
Whenever you sand PLA, there will be visible lines on the surface. You can use a file and a primer to eliminate those lines. Spray primer evenly throughout the printed object and wait for each coat to dry.
After it has dried completely, use 320-grit sandpaper for sanding the surface. Keep sanding until the surface becomes smooth. Make sure to spray sandable primer each time after sanding. Repeat the process three times.
Note: Before spraying the primer, make sure to wear a safety mask and carry out the process in a well-ventilated area.
Frequently Asked Questions
1. Does Acetone Dissolve PLA?
It is possible to dissolve PLA with acetone, but not completely unlike other solvents. Although acetone is an organic solvent and PLA is an organic polymer, they are meant to be compatible according to chemical theories.
But due to the lactide monomers becoming chemically stable after forming PLA, acetone has little effect on them.
Many users claim that dipping PLA in acetone doesn’t cause complete dissolution. Doing so causes their prints to become bleached, change the texture, and split the layers.
2. Does PLA Dissolve In Water?
PLA doesn’t dissolve in water, rather it absorbs water. The more it absorbs water, the more its bonds weaken. As a result, the filament becomes swollen and brittle.
The process doesn’t start as soon as you drop the filament in water, but it takes several years.
3. How Can I Know If My PLA Filament Has Gone Bad?
When PLA filament is exposed to moisture, it will become brittle and lead to poor-quality prints. If your printed filament breaks with a light touch, or if you hear popping sounds during the printing process, it is likely the PLA filament has gone bad.
Thus, it is recommended to store your PLA filament in an airtight container.
4. What Is The Best Temperature Range For PLA?
Generally, PLA can work to its optimal level at a temperature ranging between 185 and 205 degrees Celsius.
In order for your PLA filament to reach the lower end of the temperature range, you will need to ensure it has a thickness of 1.75 millimeters.
5. How To Remove Supports Without Using Solvents?
It is not necessary to remove supports using solvents. If you’ve printed a 3D model whose supports are easily accessible, you can carefully pull them off by hand. For hard-to-reach areas, you can snip the supports using flush-cut pliers.
Once you’ve removed all the supports, you can sand the structure using a file and sandpaper. Additionally, you can smooth the sanded surface by rubbing a small amount of lip balm if you’re not planning to paint the 3D-printed model.
6. Will My 3D Printed Object Be Damaged By Dissolving PLA?
There’s a high chance of your 3D printed objects getting damaged when you dissolve PLA with solvents. As long as you are handling the process professionally, the chances can be reduced.
It is recommended to experiment with the solvent with a sample print to see the results.
As you’ve seen, there are many different ways you can dissolve PLA filament, with the aim of achieving perfectly printed 3D models.
All the above methods have been tested and found to deliver satisfying results. Of course, you don’t have to follow all the methods at once.
Follow the one that you think is convenient for you. You can slowly try out the rest of the methods to check for any difference!
If your friends are also experiencing the same issues with PLA, you can help them learn how to dissolve PLA and get flawless prints by sharing this guide.