Title: 3D printing parameters' adjustment of elastomer TPU material using the Box-Behnken design of experiments

Authors: Foteini Vakouftsi; John D. Kechagias; Stefanos P. Zaoutsos

Addresses: Forestry, Wood Science and Design Department, University of Thessaly, Karditsa, 43100, Greece ' Forestry, Wood Science and Design Department, University of Thessaly, Karditsa, 43100, Greece ' Energy Systems Department, University of Thessaly, Larissa, 41500, Greece

Abstract: The filament material extrusion (MEX) process is a widespread additive manufacturing (AM) process that requires parameter adjustments for zero-defect parts, although it is flexible and simple. The MEX process can use many pure, composite, or blended materials in filament form to fabricate functional customised parts layer-by-layer. Due to its flexural and elongation properties, the elastomer thermoplastic polyurethane (TPU) is used in 3D printing elastic and wearable electronics or medical applications. This work aims to assess the layer thickness (LT), nozzle temperature (NT), and bed temperature (BT) on the flexural strength (sb) and elasticity modulus (E) of TPU parts produced through 3D printing. The Box-Behnken design (BBD) of experiments and the response surface methodology (RSM) are adopted. Second-order mathematical models were fitted, and the residuals were tested for normality. The results were analysed by main effect plots (MEP), contour, and surface plots. The optimisation plot showed that the 0.24 mm LT, 235°C NT, and 60°C BT optimise the process performance.

Keywords: filament material extrusion; thermoplastic polyurethane; Box-Behnken design; BBD; response surface methodology; flexural strength; main effect plots; MEP.

DOI: 10.1504/IJEDPO.2025.152106

International Journal of Experimental Design and Process Optimisation, 2025 Vol.8 No.1/2, pp.1 - 14

Received: 26 Aug 2023
Accepted: 10 Dec 2024
Published online: 09 Mar 2026 *

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