It’s frustrating when PLA filaments snap easily while trying to print 3D prototypes. Though widely used in 3D printing, PLA’s brittle nature troubles both hobbyists and professionals.
Brittle PLA causes fragmentation, reducing texture strength and leading to uneven extrusion during printing. Various theories explain why PLA filaments keep breaking, and users seek ways to overcome this brittleness. Before exploring solutions, let’s delve into the potential causes of PLA brittle.
Suitable Applications for PLA
Polylactic acid (PLA) is a versatile and environmentally friendly material used in a wide range of industries. Here, we explore the best applications for PLA, highlighting its advantages and limitations.
Examples of Ideal Applications For PLA
3D Printing
PLA is a smooth 3D surface with minimal warpage and ease of use, making it ideal for creating prototypes, educational models, and art projects.
Mix And Match Colours And Materials
PLA is available in a wide range of colors, making it ideal for pairing with soluble support materials to print parts with overhangs, complex geometries, and intricate curves.
Packaging
PLA has biodegradable properties that allow it to be used in the manufacture of disposable tableware, food containers, and packaging film.
Medical Applications
It can be used to make biodegradable implants, surgical sutures, and drug delivery systems. The material degrades safely in the body to lactic acid, thus reducing the need for surgical removal and minimizing complications.
Textiles
PLA fibers can be used in the textile industry to produce comfortable, breathable, and biodegradable fabrics.
Agriculture
PLA is used in agriculture to make biodegradable mulch, flower pots, and seedling trays.
Consumer Products
Many consumer products, such as mobile phone cases, toys, and kitchenware, are made from PLA. This material is both aesthetically pleasing and safe for items that come into direct contact with the human body and food.
Advantages and Limitations
Advantages
Eco-friendly: PLA is derived from renewable resources and is biodegradable.
Easy to print: It is one of the easiest materials to print within 3D printing, providing a good surface finish and minimal warpage.
Low odor: Unlike other plastics, PLA gives off a low odor when melted, making it more comfortable to use.
Variety of colors: A wide range of colors are available for creative and visually appealing prints.
Limitations
Brittle: PLA is more brittle than other materials such as ABS, which may limit its use in high-stress applications.
Lower heat resistance: PLA has a lower melting point, making it unsuitable for high-temperature applications.
Why PLA Filaments Get Brittle?
Polylactic acid (PLA) filament is popular for its ease of use and environmental friendliness, but it can become brittle under certain conditions. Understanding the causes of this brittleness can help prevent it and ensure better print quality.
Environmental Factors
PLA is hygroscopic, which means it absorbs moisture from the air. Excessive humidity can lead to increased brittleness. Humidity causes the polymer chains to break, which results in filaments that are prone to breakage.
Extreme temperatures, either too hot or too cold, can affect the integrity of PLA. Exposure to high temperatures can lead to filament degradation, while extremely low temperatures can make filaments more brittle and prone to breakage.
Storage Issues
Storing PLA filaments in an open environment exposes them to air and moisture. Without proper sealing, filaments can absorb moisture and dust, both of which can cause them to become brittle.
Over time, even under ideal conditions, PLA degrades. This material naturally undergoes chemical changes that lead to increased brittleness.
Manufacturing Defects
Not all PLA filaments are created equal. Variations in the manufacturing process can lead to inconsistent filament quality. Lower-quality filaments are more prone to brittleness due to weaker polymer chains and impurities.
Some manufacturers add fillers or other materials to PLA to modify its properties. While these additives can enhance certain properties, they can also make the filament more brittle.
Symptoms of a Damaged Material
Visible Cracks: Check your filament for any visible cracks along its length, as these indicate brittleness and potential breakage during printing.
Color Changes: Discoloration or uneven color distribution can signal filament degradation and potential damage.
Breakage During Printing: Frequent snapping while feeding into the printer is a clear sign of brittle filament, leading to interrupted prints.
Stringing and Blobs: Excessive stringing and blobs during printing often result from inconsistent extrusion due to brittle filaments.
Poor Print Quality: Layer separation or weak bonding in prints can indicate the use of brittle filament, affecting overall print integrity.
Surface Roughness: Rough or uneven print surfaces are often caused by brittle filament, leading to irregular material deposition.
How to Fix PLA Filaments That Have Gone Brittle？
Is there a solution when a PLA filament goes bad? There is a small way to restore the filament to its original state by applying heat. The theory supporting this suggestion is that heating causes water to evaporate, allowing the PLA to retain its original structure. Here are two ways to heat dry PLA filaments.
Heating PLA Filament Rolls
Heating the PLA filament rolls drives out moisture and restores elasticity, thus rejuvenating the material. This method is simple and easy to use and greatly improves the quality of the filament.
Steps
- Preheat oven: Set oven to low temperature, approximately 50-60°C (122-140°F).
- Place the filament: Place the filament roll in the oven on a baking tray or similar surface.
- Heat for several hours: Allow the filament to heat for 2-4 hours to allow the moisture to evaporate.
- Cool: Remove the filament and allow it to cool to room temperature before using.
Additional Tip: If the brittleness is reduced but not completely resolved, repeat the process. You can also cut off 2-3 meters of filament, as usually only a small section of the filament is affected and the rest of the filament remains intact.
Increase the Nozzle Temperature
Increasing the nozzle temperature during the printing process helps to reduce the brittleness of the PLA filament. Higher temperatures ensure smoother extrusion and better interlayer adhesion.
Steps
- Adjust printer settings: Increase the nozzle temperature by 5-10°C above the standard printing temperature for PLA.
- Test print: Make a small test print to check the quality and make adjustments if necessary.
- Monitor Performance: Observe how the filament behaves during printing and make further adjustments as necessary.
Other tips: Try different temperatures to find the optimum value. Note that these methods may not be effective if irreversible molecular changes occur in the PLA.
Precautions When Handling PLA Filaments
Prevention is always better than cure when handling brittle PLA filaments. Proper handling and storage can extend the life of the filament and maintain its quality.
Proper Storage
Airtight Containers: Store filaments in airtight containers with desiccant to keep them dry.
SHADE AND DRY PLACE: Keep filaments in a cool, dry place away from direct sunlight and moisture.
Handling Tips
Handle gently: Handle the filament gently to avoid micro-cracks or stress.
Regular Inspection: Check the filament regularly for signs of brittleness or damage and address the problem promptly.
Other Tips: Cover the spool of PLA filament with a plastic bag when using it and puncture a hole in the filament as it is fed into the 3D printer. This will minimize moisture absorption.
Conclusion
PLA is prone to breakage, which can lead to fragmentation, weaken texture, and cause uneven extrusion. This article explores the potential reasons behind PLA’s susceptibility to breakage, which users can better manage and mitigate to ensure a smoother, more reliable 3D printing experience.
