Wood Flour Pretreatment and Toughening Agents in FDM 3D-Printed PLA Biocomposites
Abstract
Investigation of wood flour surface treatments and toughening agents on FDM 3D-printed PLA biocomposites. Wood flour was treated with silane coupling agents (KH550) and acetic anhydride, examining effects on mechanical, thermal, and water absorption properties. KH550-modified wood flour/PLA showed greater tensile strength and impact resistance, while acetic anhydride treatment improved flexural properties. The addition of cellulose nanofibers (CNFs) can improve tensile strength and modulus by 84% and 63% respectively at just 1 wt% loading.
Summary
Highly practical research for wood-filled filament optimization, relevant to widely available wood PLA filaments:
Surface Treatment Comparison
- KH550 silane treatment: Better tensile strength, tensile modulus, impact strength
- Acetic anhydride treatment: Better flexural strength, flexural modulus
- Both improve water resistance vs untreated wood flour
Cellulose Nanofiber Enhancement
- Just 1 wt% CNF addition improves tensile strength by 84%
- Tensile modulus improved by 63%
- CNF acts as nanoscale reinforcement between wood particles
Commercial Relevance
- Wood PLA filaments (like ColorFabb WoodFill, Hatchbox Wood) are widely available
- Understanding treatment methods helps evaluate commercial options
- DIY filament makers can apply these treatments to wood flour
Practical Processing Tips
- Wood flour should be properly dried before compounding
- Particle size affects surface finish and nozzle wear
- Higher wood content reduces flexibility (may need toughening agents)
- Print at lower speeds to prevent fiber accumulation
Applications
- Decorative parts with natural wood aesthetic
- Furniture prototypes
- Art and craft projects
- Educational models
Wood-filled filaments are among the most accessible natural fiber composites for hobbyists.