13 - Advances in structural wood products adhesive bonding

Abstract

Adhesives used for bonding wood are many and varied. Structural wood adhesives used in industrial applications are the subject of this review. Structural adhesives are intended for applications where the strength and stiffness of the adhesive should meet or exceed the wood properties. Structural adhesives must perform in long-term load applications, such as structural wood panels, composite wood beams, and cross-laminated timber. The structural adhesives included in this review are incorporated into structural wood composites. These adhesives are thermosets that are formulated for specific product applications as well as proprietary formulations. While improved performance and lower cost are always major considerations, increasingly adhesive formulators, composite manufacturers, and customers are striving for adhesives with lower environmental impact, lower human toxicity, and less dependence on petrochemicals. This chapter focuses on the developments of structural adhesives used for wood and their performance in structural wood-based composites over the past decade. Some background is provided for context. Topics include substrate characteristics, introduction to structural wood products, standards and test methods, new development for wood adhesives, wood and adhesive interactions, bond strength characterization, toughness, bond stiffness, and durability.