Abstract：
The laser-based powder bed fusion of polymers (PBF-LB/P) process often utilizes a blend of powders with varying degrees of degradation. Specifically, for polyamide 12, the traditional reuse schema involves mixing post-processed powder with virgin powder at a predetermined ratio before reintroducing it to the process. Given that only about 15% of the powder is utilized in part production, and powders are refreshed in equal proportions, there arises a challenge with the incremental accumulation of material across build cycles. To mitigate the consumption of fresh powder relative to the actual material usage, this study introduces the incorporation of recycled material into the PBF-LB/P process. This new powder reuse schema is presented for the first time, focusing on the laser sintering process. The characteristics of the recycled powder were evaluated through scanning electron microscopy, differential scanning calorimetry, X-ray diffraction, particle size distribution, and dynamic powder flowability assessments. The findings reveal that waste powders can be effectively reused in PBF-LB/P to produce components with satisfactory mechanical properties, porosity levels, dimensional accuracy, and surface quality.
摘要：
基于激光的聚合物粉末床融合(PBF-LB/P)工艺通常利用具有不同降解程度的粉末混合物。具体来说,对于聚酰胺12,传统的再利用方案涉及在将后处理粉末与原始粉末以预定比例混合,然后再将其引入该过程。鉴于只有约15％的粉末用于零件生产，粉末以相等的比例刷新，随着材料在构建周期中的增量积累，出现了一个挑战。为了减少相对于实际材料使用量的新鲜粉末的消耗，这项研究介绍了将回收材料纳入PBF-LB/P工艺。这种新的粉末再利用模式是第一次提出，重点介绍激光烧结工艺。通过扫描电子显微镜评估了回收粉末的特性，差示扫描量热法,X射线衍射,粒度分布，和动态粉末流动性评估。结果表明，废粉可以有效地在PBF-LB/P中重复使用，以生产具有令人满意的机械性能的组件。孔隙度水平，尺寸精度，和表面质量。
