Since their inception, plastics have become indispensable materials. However, plastics used for extended periods in industrial applications are prone to aging, which negatively impacts their material behavior and performance. To ensure the long-term usability of these materials, they must be tested in real-time, in-service environments to assess degradation. In practice, however, accelerated aging techniques are commonly employed to avoid time loss. Over time, various indicators of degradation in plastics emerge, such as changes in molecular weight, cracking, and mechanical properties like strain at break and impact strength. Among these, color deterioration or change is a critical factor that helps evaluate the service life of these materials. Considering the increasing use of plastics in 3D printing today, and the growing focus on strength over aesthetics in these applications, it is particularly useful to evaluate aging in plastics based on the relationship between color and strength. The wide application of 3D printing in various industries necessitates understanding material properties under aging conditions. This study examines the effects of aging on the mechanical behavior of polylactic acid (PLA) with three different colors (yellow, orange, and red) and three different infill ratios (20%, 60%, and 100%). The samples underwent an accelerated aging process of 432 h, which included 8 h of UV radiation, 15 min of water spraying, followed by 3 h and 45 min with the UV lamps turned off. Tensile tests, bending tests, hardness measurements, and color evaluations were conducted on the samples, linking the color changes after aging with the materials’ mechanical properties. The results show that after aging, yellow samples with a 100% infill ratio exhibited a 6.9% increase in tensile strength (44.50 MPa to 47.58 MPa). Orange samples with a 100% infill ratio were less affected by aging, while red samples experienced a decrease in tensile strength across all infill ratios. Regarding bending force, increases were observed in the orange, yellow, and red samples by 10.37%, 25.05%, and 8.87%, respectively. This study underscores the importance of color selection when designing 3D-printed materials for long-term applications.

As the global 3D printing market continues to grow, the consumption of plastic products produced by 3D printers is also increasing. The role of 3D-printed products in both daily use and industrial applications has been progressively reinforced. Plastic materials undergo physical and chemical changes when exposed to environmental conditions such as temperature, light, and humidity. Consequently, they are subjected to aging during use, which shortens their service life. With the expanding use of 3D printing technology in various sectors such as healthcare, automotive, aerospace, and defense, it has become increasingly important to understand the changes (potential decreases or losses) in the performance of these materials after long-term exposure to environmental conditions. This study aims to contribute to the understanding of potential changes in 3D-printed ABS Plus material by examining the phenomenon of aging induced by exposure to radiation from a xenon arc lamp. ABS Plus samples of different colors (yellow, purple, red, green, and blue) were subjected to aging for 0, 112, 225, 337, and 450 h using a xenon arc lamp. To investigate the effects of aging, the mechanical (tensile, flexural, and hardness) and optical (color and gloss variations) properties of the samples were compared before and after aging. Following the mechanical tests, the fracture modes of the specimens were also examined. In addition, Scanning Electron Microscope (SEM) images were obtained to further discuss the effects of aging. The results revealed that the mechanical properties of the reference samples varied depending on color. The highest tensile strength was observed in the yellow samples (33.46 MPa), while the highest flexural strength was recorded in the green samples (58.46 MPa). After aging, the lowest tensile strength was found in the purple samples aged for 337 h (24.63 MPa), whereas the lowest bending force was measured in the red samples aged for 450 h (45.27 N). Overall, the mechanical properties of the samples varied with aging duration, with the blue and green specimens being the least affected. For the blue specimens, after 112, 225, and 337 h of aging, an increase in tensile strength was observed (2.77%, 10.54%, and 9.58%, respectively), while a decrease occurred after 450 h of aging (−6.22%). For the green specimens, after 112, 225, and 337 h of aging, the tensile strength remained similar to that of the reference sample (−2.97%, 0.23%, and 0.05%, respectively) but decreased after 445 h of aging (−8.09%). In terms of optical properties, the most significant color change (−23.51) was observed in the purple samples. Gloss measurements indicated that the impact of aging increased with exposure time.