Title: Multiplexing Core & Sheath Extrusion System Development For Additive Manufacturing For Inner-Bead Multi-Material Capability

Authors: Halil Tekinalp, Alex Roschli, Jesse Heineman, Vipin Kumar, Paritosh Mhatre, Umesh Marathe, Segun Isaac Talabi, Sanjita Wasti, Jay Reynolds, David Nuttall, Soydan Ozcan

DOI: 10.33599/nasampe/c.25.148

Abstract: Single-feed polymer extruders are widely used in large-format additive manufacturing (AM) systems; however, the increasing demand for multi-material functionality within a single part has driven significant innovation in this field. One approach involves robotic pick-and-place operations, while another explores mechanical switching of feed lines during extrusion. Although robotic pick-and-drop systems offer flexibility, they introduce longer layer times during material changes, which can negatively affect the structural integrity of the part. On the other hand, mechanical feed switching causes delays in material transitions, as the existing material must be flushed before the new material emerges from the nozzle. This poses particular challenges for smaller or more intricate parts. In this study we are developing a unique multiplexing extrusion system with core & sheath nozzle that combines two extruders via co-extrusion. This allows for a unique inside and outside inner-bead (i.e., within the same bead) multi-material capability. We believe that this technology will allow for combining neat and filled materials, ductile and stronger materials, and many other combinations to address the problems aforementioned above and disrupt the AM technology creating new opportunities and opening application areas.

References: 1. Post, B. K., et al. "The economics of big area additive manufacturing." (2016). 12 2. “Tradesman SeriesTM P3-44.” JuggerBot 3D, 6 Apr. 2023, juggerbot3d.com/products/tradesman-series-p3-44/. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Marrett, Duane. Thermwood LSAM - Large Scale Additive Manufacturing, www.thermwood.com/lsam_home.htm. Accessed 4 May 2024. “Heron AM.” Caracol, 8 Apr. 2024, www.caracol-am.com/technologies/heron-am. Dormeier, S. "Extruder control." IFAC Proceedings Volumes 13.12 (1980): 551-560. Chesser, Phillip, et al. "Extrusion control for high quality printing on Big Area Additive Manufacturing (BAAM) systems." Additive Manufacturing 28 (2019): 445455. Roschli, Alex Christopher. "Dynamic Extruder Control for Polymer Printing in Big Area Additive Manufacturing." (2016). Compton, Brett G., et al. "Thermal analysis of additive manufacturing of large-scale thermoplastic polymer composites." Additive Manufacturing 17 (2017): 77-86. Wolszczak, Piotr, et al. "Heat distribution in material during fused deposition modelling." Rapid Prototyping Journal 24.3 (2018): 615-622. “Learn More about Our Robot Based Solutions for Large Scale 3D Printing.” CEAD, 1 Nov. 2023, ceadgroup.com/solutions/robot-based-solutions/. Kalia, Karun et. al. "A Co-extrusion Additive Manufacturing Process with Mixer Nozzle to Dynamically Control Blowing Agent Content and Print Functionally Graded Foams." ACS Applied Engineering Materials 3.3 (2025): 625-635. Tekinalp, Halil, et al. "Multiplexing extrusion system development for increased throughput, flow accuracy and improved microstructure." 10th Composites and Advanced Materials Expo, CAMX 2024. The Composites and Advanced Materials Expo (CAMX), 2024.

Conference: CAMX 2025

Publication Date: 2025/09/08

SKU: 148

Pages: 13

Price: $26.00