Assessing thermal-mechanical properties of wood powder cellulose-based composites for 3D-printed architectural components

Abstract

The construction industry is a major contributor to global CO₂ emissions, necessitating sustainable alternatives for building materials. Additive manufacturing (AM) using wood-based composites offers an eco-friendly solution for thermal insulation applications. This study explores the thermal and mechanical properties of wood powder–carboxymethyl cellulose composites fabricated via liquid deposition modeling (LDM). Six formulations incorporating industrial wood waste from beech and oak, with varied particle sizes, were developed to evaluate their extrudability, structural stability, and insulation efficiency. Material characterization included thermal conductivity testing via the transient plane source method and compressive strength assessment following ISO standards. Results indicate that particle size and wood species significantly influence material properties. Finer wood particles yielded higher compressive strength, whereas coarser particles exhibited lower conductivity, enhancing insulation performance. The best-performing formulation (B2: beech wood, medium particle size) demonstrated a balanced thermal conductivity of 0.188 W/m·K and compressive strength of 3 MPa. To assess large-scale buildability, a 3D-printed block component (200 × 350 × 220 mm) was fabricated. A refined formulation with reduced water improved print stability, demonstrating the viability of LDM for producing rigid, lightweight insulation blocks. This research establishes a foundational understanding of AM wood composites for thermal insulation, offering insights into material formulation, printability, and structural behavior. The findings underscore the potential of bio-based AM in sustainable construction, paving the way for scalable applications of wood waste in energy-efficient building systems. Future work will focus on optimizing binder composition, refining printing strategies, and exploring reinforcement techniques to enhance mechanical properties while maintaining thermal efficiency.