(129c) Weld Formation in Material Extrusion Additive Manufacturing
AIChE Annual Meeting
2018
2018 AIChE Annual Meeting
Materials Engineering and Sciences Division
Area Plenary: Area 8A Emerging Areas in Polymer Science and Engineering II (Invited Talks)
Monday, October 29, 2018 - 1:40pm to 2:15pm
In polymer extrusion 3D printing, a material extrusion AM method, thermoplastic filament is extruded though a rastering nozzle on the previous layer. The resulting strength of the 3D produced part is limited by the strength of the weld between each layer. While numerous factors can affect the weld strength, the temperature of the extrudate and the previous layer dictate the amount of interdiffusion and thus the weld strength. Temperature measurements were performed using forward looking infrared imaging. Interdiffusion estimates were calculated from temperature profiles, normalized using horizontal shift factors from offline rheological measurements of the neat polymer. Weld strength was measured directly by mode III fracture using a simplified geometry limiting the measurement to a single weld. Since the processing conditions are known aprioi this approach provides the data needed to estimate the final build strength at time of design. The resulting agreement between interdiffusion estimates and weld strength for a range of printing conditions and thermoplastics are discussed.