Characterization of PA‐12 specimens fabricated by projection sintering at various sintering parameters

• Published in: Polymer engineering and science 2021-01, Vol.61 (1), p.221-233
• Main Authors: Kaur, Taranjot, Nussbaum, Justin, Lee, Sanboh, Rodriguez, Kevin, Crane, Nathan B., Harmon, Julie
• Format: Article
• Language: English
• Subjects: 3D printing; Additive manufacturing; Analysis; Crystal structure; Crystallinity; Dynamic mechanical properties; Fourier transforms; Hardness; Ion beams; large area projection sintering; Laser cooling; Laser sintering; Light beams; Mechanical engineering; Mechanical properties; Microhardness; Parameters; Particle fusion; Polyamide resins; Polyamides; polyamide‐12; powder bed fusion; Sintering; Thermodynamic properties
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.25570

Large area projection sintering (LAPS) promises to be a new method in the field of additive manufacturing. Developed in the Mechanical Engineering Department, University of South Florida, LAPS uses long exposure times over a broad area of powder to fuse into dense, reproducible materials. In contrast, LS, a common powder‐based additive manufacturing, uses a focused beam of light scanned quickly over the material. Local regions of concentrated high‐energy bursts of light lead to higher peak temperatures and differing cooling dynamics and overall crystallinity. The mechanical properties of laser sintered specimens suffer because of uneven particle fusion. LAPS offers the capacity to fine‐tune fusion properties through enhanced thermodynamic control of the heating and cooling profiles for sintering. Further research is required to identify the relationship between LAPS build settings and part properties to enable the fabrication of custom parts with desired properties. This study examines the influence of LAPS sintering parameters on chemical structures, crystallinity, mechanical, and thermal properties of polyamide‐12 specimens using powder X‐ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, small‐angle X‐ray scattering, scanning electron microscopy, and microhardness testing. It was observed that higher crystallinity was imparted to specimens that were sintered for a shorter time and vice versa.