The molecular structure of plastics makes them susceptible to degradation from exposure to ultraviolet (UV) light. The degree of distress depends on the specific polymer and the UV light’s wavelength. That’s why when you choose a 3D printing material, it’s essential to understand the polymer’s characteristics and the conditions it will experience in its intended application.
Recently, Stratasys additive manufacturing engineers tested 11 FDM thermoplastics to measure the impact of UV exposure. Test samples (called plaques) were printed in the flat (XY) and upright c(XZ) orientations and then put inside a QUV Chamber. The QUV chamber can simulate months or years of exposure to UV and humidity.
The samples were inspected for color change using the Commission Internationale de l’Eclairage (International Commission on Illumination) standard. Each plaque was photographed to record any color change. In addition to visual impact, all the plaques were tested to determine the effect on mechanical properties.
Tested Performance Properties:
• Yield strength
• Stress at break
• Elongation at break
• Modulus
Test results varied by material. For example, visual changes included colors becoming darker or skewing toward a yellow, red, or blue hue. Mechanical properties also varied, with some materials exhibiting an increase in properties such as tensile strength, while others either remained the same, or degraded somewhat.
For more detailed information on which specific FDM polymers were tested and the tabulated results for each material, download the white paper below.
