Processing of High Performance Fluoropolymers by Laser Sintering

One of the main limitations of laser sintering (LS) is its narrow material portfolio. Fluoropolymers are a family of polymers with outstanding properties such as wide service temperatures (−260 °C - +260 °C), excellent resistance to chemicals, sunlight, flames, and weathering without the addition of stabilizers, plasticizers or fillers. In this study, fluoropolymers such as perfluoroalkoxy (PFA) and polychlorotrifluoroethylene (PCTFE) have been used in laser sintering. PFA and PCTFE have melting temperatures of 304 °C and 210 °C respectively which make them challenging to process. Our results demonstrate the feasibility of these materials in LS and that warping was the major issue encountered due to the relatively low powder bed temperature of ∼182 °C. We illustrate how particle size, additives, and thermal conditioning affect the powder flow and how the warping can be decreased by utilizing a modified build plate, and different scan strategies and part orientations. Flat sheets were successfully produced with potential use in membrane-based applications.