Researchers have made tremendous progress in the construction, automotive, and aerospace industries by successfully connecting wood and plastic without the need of glue or screws. Because it requires adhesives or mechanical fasteners, wood which is prized for its strength, light weight, and environmental benefits often has limitations when paired with other materials like plastic or metal. The structural integrity of wood might be jeopardized by screws and adhesives that deteriorate over time. Two novel bonding techniques have been developed by materials scientists at Graz University of Technology (TU Graz) in Austria with the goal of increasing the versatility and environmental friendliness of wood.
The first method involves 3D printing plastic composites directly onto wood surfaces. The plastic flows into the wood’s natural pores, undergoing a chemical reaction similar to traditional glue. When tested, the joint eventually failed, but the presence of both plastic in the wood pores and wood fibers in the plastic indicated that the joint itself remained intact, suggesting a strong bond. Researchers believe that refining this technique such as using lasers or etching to increase the wood’s pore density could further enhance the strength of the bond.
The second method employs ultrasonic vibration. A device called a sonotrode generates heat through friction when it comes in contact with the plastic composite, causing the plastic to melt and infiltrate the wood’s pores. This creates a stable bond, particularly suitable for long, flat surfaces.
The research team tested both methods with different woods, such as beech and oak, and plastic composites, like carbon fiber-reinforced polyamide. Though the team also experimented with metals, further details are yet to be disclosed. The process has been patented, and there are optimistic projections that this technology could soon be adopted in manufacturing, offering a more sustainable and efficient alternative to traditional bonding methods.