Optimization of process parameters of 3D printed thermoplastic elastomeric materials using statistical modeling with particular reference to mechanical properties and print quality

Additive manufacturing of thermoplastic elastomeric material (TPE) using direct ink writing (DIW) based printing technique opens new horizons for various applications. However, the most crucial process in DIW 3D printing is the optimization of printing parameters to obtain high-quality products both in terms of aesthetics and strength. In this work, statistical models were developed considering layer height, print speed, and, ink concentration to obtain the optimized print quality product from the blend of thermoplastic polyurethane (TPU)/ epichlorohydrin − ethylene oxide − allyl glycidyl ether elastomer (GECO) based TPE materials. Experiments were designed according to the central composite design (CCD) scheme and the influence of input printing parameters on shrinkage and tensile strength was analyzed. The significance of each parameter was systematically studied using the response surface method. For both responses, shrinkage, and tensile strength, printing speed was found to be the most significant parameter. Ink concentration significantly affected tensile strength with a contribution of ∼ 34%. On the other hand, the layer height, with a contribution of ∼ 22% significantly affected the shrinkage behaviour of the 3D printed sample. Finally, multi-objective optimization was performed using a genetic algorithm to identify the optimal 3D printing parameters of the developed TPE materials.