Roll-to-Roll Manufacturing of Biomass Material for Sustainable Thermal Insulation Application

Abstract

Abstract. Biomass materials are agricultural byproducts generated following seasonal harvesting. Their unique fibrous structure imparts low thermal conductivity, high porosity, and resilience, making biomass a sustainable and low-cost alternative to conventional synthetic insulation materials. Additive manufacturing (AM) has shown promise in fabricating biomass-based functional structures due to its flexibility in accommodating irregular feedstock and its ability to preserve the hierarchical porous microstructures during the layer-by-layer deposition. While AM is effective in prototyping, the scalability of AM techniques such as the extrusion-based process has long been a bottleneck for industry-scale productions due to low deposition rate and interlayer delamination. Mitigating the scalability challenge requires a new manufacturing process that enables continuous, high-throughput deposition while maintaining material uniformity and structural integrity. In this work, we develop a roll-to-roll (R2R) high-fiber manufacturing platform to fabricate insulation panels directly from wheat straw fiber slurries. A novel deposition mechanism that leverages a multi-level manifold and slot-die nozzles is implemented to achieve high-throughput, planar slurry deposition. The uniformity of fabricated panels is improved through both material formulation and process design. Rheological studies are conducted to characterize the viscoelastic behavior of the slurry, while computational fluid dynamics simulations are used to optimize the slot-die geometry for uniform flow distribution. The R2R configuration enables continuous manufacturing and increases throughput to 78 cm3/s. The fabricated insulation panels demonstrate comparable performance to existing synthetic products, along with improved mechanical strength. This new manufacturing process demonstrates a sustainable pathway to repurpose agricultural waste into value-added, environmentally friendly building materials.