Simultaneous processing of thermosets and thermoplastics in additive manufacturing of multi-material polymer parts

Multi-material additive manufacturing (AM) pushes the barriers of complex part production with a comprehensive and complementary material spectrum to unprecedented heights. The experimental “Fusion Jetting” technology is one of the first attempts to simultaneously process thermoplastics and thermosets within a single AM process to functional multi-material parts. Applications lie in the field of load-path optimized reinforcements, hard-soft and smart structures as well as the strategic variation of the mechanical, thermal, and electro-magnetic part properties. This investigation focuses on the implementation of UV-curable acrylates within thermoplastic polyurethane (TPU) parts utilizing an experimental laser-based AM process to specifically alter the mechanical behavior of future parts. Process parameters like the laser power or the acrylate content within each plane are strategically varied to examine their respective impact on the mechanical and microscopic part properties. Based on tensile testing results, an increase of the Young’s Modulus for TPU parts with acrylate reinforcements is detected. The choice of the sequence of the individual process steps proofs fundamental towards the laser/material interaction and the infiltration behavior. This includes the detection of increased infiltration of the acrylate within melted regions of TPU using low energy densities resulting in parts with increased porosity. The results are further discussed towards the bonding behavior between the materials, including the potential impact of selected process parameters on the visually detected delamination behavior during mechanical testing.     «

Multi-material additive manufacturing (AM) pushes the barriers of complex part production with a comprehensive and complementary material spectrum to unprecedented heights. The experimental “Fusion Jetting” technology is one of the first attempts to simultaneously process thermoplastics and thermosets within a single AM process to functional multi-material parts. Applications lie in the field of load-path optimized reinforcements, hard-soft and smart structures as well as the strategic variation...     »