Understanding the role of microcrystalline cellulose for the development of high fidelity 3D printing of Kraft lignin filaments via fusion deposition modeling

A 3D Benchy was successfully printed using kraft lignin as the primary component of a fused deposition modeling (FDM) filament. The filament was produced by compounding the kraft lignin (TcC) with thermoplastic polyurethane (TPU) and adding up to 10% of micro crystalline cellulose (MCC). The compound was then extruded into a 1.75 mm filament. The influence of the addition of MCC on the morphological, thermal, rheological, and mechanical properties of the composite filament was studied. Rheological data reveal that the addition of MCC increases the processable temperature range of the filament by 10°C to 190–210°C. The mechanical data show that the addition of MCC reduces the tensile strength by 27.5% while increasing the Young's Modulus by 40.7%. When printed, the lignin-based filament shows high surface adhesion between the layers, with high resolution and dimensional accuracy, along with excellent shape retention of printed parts.