Disadvantages of PLA
Are your PLA 3D prints causing you unforeseen problems? Even though PLA is great because it's biodegradable and easy to use, it does have some restrictions that can affect how long your designs last. If you want your 3D printing projects to turn out well, you need to be aware of these drawbacks and figure out how to fix them.
Disadvantages of Printing with PLA
1. Mechanical Weakness
PLA is a more brittle 3D printing material than ABS and PETG. Because of its fragility, it is not a good choice for components that need to be flexible or subjected to mechanical stress. Instead of deforming, parts made of PLA may shatter or split when subjected to pressure.
2. Heat Sensitivity
The low glass transition temperature of PLA, which is about 60°C, is one of its major disadvantages. This means that items made from PLA can undergo deformation when heated. An example would be the possibility of shape loss or warping for a PLA part left in a hot automobile all summer long.
3. Limited Outdoor Use
PLA's heat and ultraviolet light sensitivity make it unsuitable for outdoor use. Prolonged exposure to sunlight can result in degradation, discoloration, and structural weakness. PLA is not a good choice for damp areas because it can degrade faster when exposed to moisture.
4. Chemical Resistance Issues
When exposed to chemicals, PLA degrades quickly. Some cleaning chemicals, oils, and solvents can dissolve or dilute the substance. This constraint makes it unsuitable for use in settings where people are likely to come into contact with chemicals.
5. Problems with Layer Adhesion
Although PLA has excellent layer adhesion when printed, interlayer bonding problems do occur from time to time. The result of this issue can be components that are fragile along the grain boundaries and hence easily cracked or broken when subjected to stress.
6. Few Options for Post-Processing
It can be difficult to post-process PLA. Because of the frictional heat, PLA components could melt if you sand them. Acetone smoothing, a typical method for achieving a glossy surface with ABS, also doesn't work well with PLA.
7. Misunderstandings Regarding Environmental Impact
The advertised biodegradability of PLA belies the fact that its proper breakdown necessitates the use of industrial composting facilities. Decomposition of PLA can be a lengthy process under ordinary environmental circumstances. Misunderstandings like these can lead to problems with waste management and environmental issues.
What Can We Do to Get Rid of These Drawbacks?
1. Raising Structural Stability
Consider annealing, a heat treatment that enhances crystallinity and strength, to make PLA prints with better mechanical strength. The printed item is heated to a certain temperature during the annealing process, which reorganizes the polymer chains into a more crystalline structure. This process improves the part's strength and thermal resistance. One way to enhance the mechanical qualities of PLA parts is to bake them at 70–80°C for a set amount of time.
Printing with a higher infill density also increases strength. Denser pieces are stronger and last longer when the infill percentage is higher. The use of 100% infill printing improves the resistance of printed items to distortion and dimensional changes.
2. Reducing Heat Loss
Mechanical strength and heat resistance are both improved by annealing. Prints made of PLA can have their heat deflection temperature raised through controlled heat treatment, making them better suited for uses requiring elevated temperatures. To enable structural reorganization, this procedure entails heating the printed object to a temperature slightly below PLA's melting point and keeping it at that temperature for a particular duration.
3. Raising the Bar for Outdoor Useful Lifespan
To prevent the degradation of PLA prints caused by sunshine, consider employing UV-resistant coatings for outdoor applications. Protect it from the sun's rays and keep it looking good for longer by spraying it with a transparent acrylic or polyurethane. You can add an additional layer of protection against environmental conditions by painting the PLA object with outdoor-grade paints.
4. Reducing Chemical Exposure
Coating something with a protective material can make it more resistant to chemicals. Coatings made of epoxy resin, for instance, can act as a barrier to keep chemicals from coming into contact with PLA. Parts that come into contact with solvents or oils can benefit greatly from this technique, as the coating protects the material beneath.
5. Resolving Problems with Layer Adhesion
You can reduce the likelihood of layer adhesion problems by printing at the correct temperature and using the correct cooling settings. Improving interlayer bonding is possible by printing within the manufacturer-recommended temperature range and modifying cooling fans to provide sufficient cooling without overheating. Keeping the printing area dry and the filament free of moisture are two other factors that can improve layer adhesion.
6. Raising the Bar for Post-Processing Freedom
Although acetone vapor smoothing and other conventional methods of surface smoothing do not work on PLA, there are other options available. To have a smooth finish, sand the area and then add filler primer. For example, some have found that, with enough time and effort, combining Bondo with Rustoleum Filler Primer produces adequate results.
Best 3D Modeling Software
There are many 3D modeling software applications available, each designed with different features and workflows. For this tutorial, we recommend using SelfCAD because it provides a complete 3D design environment in a single platform. In addition to powerful modeling and sculpting tools, SelfCAD includes a built-in online slicer for preparing models for 3D printing, 3D shape generators that simplify the creation of complex objects, and interactive tutorials that make learning the software straightforward.
Whether you're creating functional parts, artistic models, or educational projects, SelfCAD offers an efficient workflow that eliminates the need to switch between multiple applications.
Engineering with PLA Responsibly
Despite PLA's many benefits for 3D printing—including reduced production environmental impact and simplicity of use—its drawbacks render it unsuitable for specific uses. Before deciding on PLA, users should give serious thought to these characteristics, particularly if their projects call for mechanical strength, heat resistance, chemical exposure, or outdoor durability. To ensure that 3D-printed components last and function as intended, it is crucial to select the appropriate material tailored to the project's specific needs.
Frequently Asked Questions
1. What are the drawbacks of PLA?
Some people are worried that PLA won't hold up well in hot environments. Prolonged exposure to direct sunlight can cause PLA products to distort, especially on very hot summer days. Compared to other polymers, PLA's increased permeability is a result of its organic composition.
2. What is the post-print durability of PLA?
PLA, when stored at room temperature, has an extremely long shelf life—roughly 12–18 years. 3D-printed PLA items have a shelf life of one month, two years, or even decades, depending on storage conditions. Depending on its surroundings, it can degrade at varying speeds.
3. Why isn't PLA more commonly utilized?
Recyclable PLA is not compatible with any other polymers. It is not possible to recycle PLA with other plastics since its characteristics are different. Additionally, it is arguable that combining PLA with other plastics will significantly reduce its recycling potential and value.
4. Is PLA safe for printing?
PLA's low printing temperatures, little warping, and user-friendliness have made it a popular choice. The fact that it is non-toxic and doesn't produce any nasty fumes or harsh smells when printed means that it is usually safe to use at home. However, you should always make sure your printing area has enough airflow.
5. How are PLA and ABS filaments different from one another?
While PLA is stronger and stiffer, ABS is a lighter, tougher material that has more practical uses beyond just hobbyists. In comparison to other materials, ABS is somewhat more long-lasting, 25% lighter, and four times more impact-resistant.