Experimental Study of Microscopic Morphology and Material Property for Recycled Polyamide 12 Powder in Selective Laser Sintering

Abstract

Selective laser sintering has become one of the most popular additive manufacturing technologies owing to its great capability of fabricating complex structures with reduced or even eliminated need for the support structure. Meanwhile, an average of 50% to 70% of the consumed powder materials is not directly used for part fabrication. To reduce material waste and enhance material usage efficiency, research studies have been conducted to facilitate the recycling and/or reusing of the waste powder in selective laser sintering. In this research, polyamide 12 powders are studied including virgin powder, waste powder, recycled powder, and mixed powder (with a 30% refresh rate) in terms of their microscopic morphology and material properties. In addition, the location of the powder sampled from the build chamber is also studied for its impact on the powder size and shape. Experimental results show that the average particle size does not change much in different samples, but the standard deviation increases in waste powder. Furthermore, the averaged ultimate tensile strength of test specimens fabricated with virgin powder is around 25% higher than specimens made with mixed powder (30% virgin powder and 70% recycled powder), showing a clear mechanical degradation.

Recovery of residual polyamide (PA12) from polymer powder bed fusion additive manufacturing process through a binder jetting process

“…, 2020; Wudy and Drummer, 2019; Yang et al. , 2021) are affected, while the average particle size does not change significantly (Al Amin et al. , 2022; Arbelaez Ríos et al.…”

“…Commonly, PA12 recycled is mixed with 30%-50% of virgin powder to refresh the properties (Gomes et al, 2022a;Wegner et al, 2014). However, even after refreshing an aging powder, the mechanical (Gomes et al, 2022b;Guo et al, 2023;Lopes et al, 2021;Mwania et al, 2020;Yao et al, 2020) and thermal properties (Alo et al, 2023a;He et al, 2022;Mwania et al, 2020;Wudy and Drummer, 2019;Yang et al, 2021) are affected, while the average particle size does not change significantly (Al Amin et al, 2022;Arbelaez Ríos et al, 2021).…”