Selective Sheet Extrusion: A Novel Manufacturing Process for Large-Format Material Extrusion

Abstract

The trade-off between resolution and speed represents a significant challenge when extrusion-based additive manufacturing (AM) is used for large-format additive manufacturing (LFAM). This paper presents an analysis of a new material extrusion process, named selective sheet extrusion (SSE), that aims to decouple these parameters. Unlike traditional single-nozzle material extrusion processes, SSE utilizes a single, very wide nozzle through which extrusion is controlled by an array of dynamically actuated teeth at the nozzle outlet. This allows the system to deposit a selectively structured sheet of material with each pass, potentially enabling the deposition of an entire layer of a part in a single pass. An analysis of the theoretical performance of the SSE technology, in terms of speed and material efficiency in comparison with single-nozzle extrusion systems, predicted speed increases of 2–3 times for the geometries that were explored. The analysis was then validated through experimental work that indicated a normalized improvement in print speed of between 2.3 and 2.5 times using a proof-of-concept SSE prototype. The SSE concept expands the opportunity frontier of LFAM technologies by enabling enhanced print speeds, while maintaining higher resolutions at scale. This enhancement in speed and/or resolution could have significant benefits, especially in large-scale prints that benefit from enhanced internal resolution.