García Rodríguez Alejandro, Espejo Mora Edgar, Velasco Peña Marco Antonio, Narváez Tovar Carlos Alberto
Facultad de Ingeniería Mecánica, Universidad Santo Tómas, Carrera 9 No 51-11, Bogotá 110231, Colombia.
Mechanical and Mechatronics Engineering Department, Universidad Nacional de Colombia, Carrera 45 No 26-85, Building 407, Bogotá 111321, Colombia.
Polymers (Basel). 2025 Feb 22;17(5):577. doi: 10.3390/polym17050577.
This study investigated the effects of multiple laser sintering (LS) cycles on a polyamide 12 powder mixture of 70% recycled material and 30% virgin polymer. This research aimed to understand how repeated LS processing influences this specific powder mixture's thermal and structural properties, which is crucial for optimising its performance in additive manufacturing applications. A thermal analysis revealed significant changes in the thermal behaviour of the powder over successive build cycles. Specifically, there was an observed increase in both the melting temperature and the crystallinity of the powder, alongside a notable decrease in the crystallisation temperature. These alterations suggest that the repeated LS cycles affect the thermal profiles and potentially enhance the material's stability and usability in additive manufacturing processes. Additionally, a particle size distribution analysis indicated statistically significant differences between the initial and post-sintering states of the powder. These differences are significant as they can influence factors such as flowability and packing density, which are critical for the efficiency of additive manufacturing applications. Microscopic observations further revealed a strong correlation between the crystal morphologies and particle shapes, indicating that the structural changes occurring during processing are inter-related. The relationship underscores the importance of understanding microstructural evolution and the mechanical properties of the final printed products. These findings provide crucial insights into the microstructural evolution and thermal behaviour of recycled PA12 powder during multiple LS processing cycles. This study aids in developing practical strategies for sustainable and efficient powder recycling within the realm of additive manufacturing. By examining the intricate dynamics at play, the research opens avenues for enhancing the performance and environmental sustainability of 3D printing technologies, making them more accessible for various industrial applications.
本研究调查了多次激光烧结（LS）循环对由70%回收材料和30%原始聚合物组成的聚酰胺12粉末混合物的影响。本研究旨在了解重复的LS加工如何影响这种特定粉末混合物的热性能和结构性能，这对于优化其在增材制造应用中的性能至关重要。热分析表明，在连续的构建循环中，粉末的热行为发生了显著变化。具体而言，观察到粉末的熔点和结晶度均有所增加，同时结晶温度显著降低。这些变化表明，重复的LS循环会影响热曲线，并可能提高材料在增材制造过程中的稳定性和可用性。此外，粒度分布分析表明，粉末的初始状态和烧结后状态之间存在统计学上的显著差异。这些差异很重要，因为它们会影响诸如流动性和堆积密度等因素，而这些因素对于增材制造应用的效率至关重要。微观观察进一步揭示了晶体形态与颗粒形状之间的强相关性，表明加工过程中发生的结构变化是相互关联的。这种关系强调了理解微观结构演变和最终打印产品机械性能的重要性。这些发现为多次LS加工循环过程中回收PA12粉末的微观结构演变和热行为提供了关键见解。本研究有助于制定增材制造领域可持续高效粉末回收的实用策略。通过研究其中复杂的动态过程，该研究为提高3D打印技术的性能和环境可持续性开辟了道路，使其更易于应用于各种工业领域。
