Signs Your PLA Filament Has Degraded

Many 3D printing enthusiasts have faced this frustrating scenario: carefully stored PLA filament that consistently fails during printing, leaving you wondering if the material has "expired." While PLA doesn't technically expire, it can degrade over time, especially when exposed to moisture. Here's how to identify signs of compromised PLA filament and avoid unnecessary waste.

Polylactic acid (PLA), one of the most popular 3D printing materials, offers ease of use and environmental benefits. However, its sensitivity to humidity makes proper storage crucial. When PLA absorbs moisture from the air, its performance deteriorates, leading to printing failures and subpar results.

Begin your assessment by examining the filament's appearance. Compromised PLA may show:

• A rough or dull surface texture
• Visible bubbles or micro-fractures
• Discoloration or cloudiness

These changes occur when absorbed water vaporizes during heating, altering the filament's structure.

Next, evaluate the material's physical properties. Quality PLA filament should demonstrate some flexibility, bending slightly without breaking. If your filament snaps easily during gentle bending or feels unusually brittle, it has likely absorbed excessive moisture.

• Inconsistent extrusion causing rough surface finishes
• Reduced layer adhesion leading to structural weakness
• Audible popping or hissing sounds from the nozzle
• Unusual odors during printing
• Visible steam or small bubbles in extruded material

If you suspect moisture damage, try rejuvenating the filament through controlled drying:

• Use a food dehydrator or specialized filament dryer
• Maintain temperatures between 104-122°F (40-50°C)
• Dry for 4-6 hours, adjusting based on filament diameter and humidity levels

Successful drying should restore printing performance. If problems persist after thorough drying, replacement may be necessary.

By recognizing these signs early and taking appropriate action, you can maintain your PLA filament in optimal condition, ensuring consistent print quality and minimizing material waste.