1. Evaluation of the effects of extrusion parameters on the swelling of extruded filament in an innovative 3D printer containing a vertical co-rotating twin-screw extrusion unit.
- Author
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Silva, Dávila Moreira Lopes, Barbosa, Patrícia Alves, Chinelatto, Marcelo Aparecido, and de Castro Silveira, Zilda
- Subjects
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SWELLING of materials , *MANUFACTURING processes , *SURFACE texture , *SCANNING electron microscopy , *3-D printers , *SCREWS - Abstract
This paper investigates the die swell phenomenon in material extrusion additive manufacturing (MEX-AM) using customized 3D printing equipment with a co-rotating vertical twin-screw extrusion unit (Co-TSE AM). In twin-screw-based MEX-AM, the output rate is independent of the screws' rotational speed, and the complex die geometry impacts the thermomechanical behavior of the flow, thus affecting the die swell ratio (DSR). Towards exploring two premises, namely, influence of the Co-TSE AM die's complex geometry and influence of the main extrusion parameters, this study estimated the shear rate in the screws and die analytically and designed experiments to evaluate the effects of screw rotational speed, output rate, and nozzle diameter on the DSR. Scanning electron microscopy (SEM) assessed filament morphology and surface texture. The main results show DSR averages between 1.28 and 1.67 and both output rate and nozzle diameter significantly influence DSR, whereas screw rotational speed has no significant impact on the thermomechanical environment affecting material swelling. Filament width and height are differently influenced by standoff distance and print platform speed. The study enhances the understanding of the way extrusion parameters affect die swell in twin-screw MEX-AM, contributing to improved control and quality in single-step additive manufacturing processes. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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