Shear Strength and Microscopic Characterization of a Bamboo Bonding Interface with Phenol Formaldehyde Resins Modified with Larch Thanaka and Urea

Direct strain distribution and finite-element-analysis simulation of the bonding interface of bamboo laminated lumber with ultrasound-treated bamboo strips

“…The geometrical model was set up and then meshed into a finite number of units. Given that meshing could influence the calculation accuracy, the meshing quantity, density, and quality were taken into account (Guan et al 2016). The model geometry was meshed with refinements in the bonding interface with mesh of 0.1 mm×0.35 mm, where strain and stress concentrations were expected (Fig.…”

“…(Xu et al 2004;Correal and Ramirez 2010;Darzi et al 2018;Bakar et al 2019;Li et al 2019;Rusch et al 2019). Laminated bamboo lumber is bonded with adhesives, e.g., phenolic resin, so bond line and bonding interface characterization is important to ensure bonding performance (Correal and Ramirez 2010;Guan et al 2016). It is necessary to improve adhesive penetration into the bamboo matrix.…”

“…However, bamboo has a dense surface and an intrinsic lack of transverse tissue, e.g., wood rays (Liese 1998). Horizontal transmission only relies on pits in the cell walls, which may result in the shallow penetration of the adhesive into the bamboo and lead to unsatisfactory bonding performance (Ma 2009;Guan et al , 2016. Research has shown that micro-jets generated from ultrasonic cavitation may cause shock and a shear effect on the surface cells of bamboo strips.…”

“…It is known that the properties of bamboo engineered materials depends not only on the bamboo matrix itself but also on the properties of the bonding interface generated by mutual contacts with adhesives. The interface between the adhesive and bamboo plays a vital role in ensuring the performance of bamboo-based composite structure materials and their application (Guan et al 2016). The strain distribution in the interface of wood composite materials influences the stress transmission and dispersion, which may influence the macro-performance of wood-based composites in terms of dimensional stability, durability, and shear strength (Serrano and Enquist 2005;Jeong et al 2006;Gindl and Muller 2016).…”

Surfactant-Induced Reconfiguration of Urea-Formaldehyde Resins Enables Improved Surface Properties and Gluability of Bamboo

“…They are widely used in furniture, flooring, construction, civil engineering, and other fields [ 8 , 9 , 10 ]. However, due to the absence of transverse ray cells in bamboo tissues and the unobvious flow, wetting, and penetration depth of the liquid adhesive on the surface of the bamboo, the crosslinking of the adhesive and the bamboo material is unable to achieve the mechanical coupling effect with the wood [ 11 , 12 , 13 ]. In addition, bamboo green and bamboo yellow contain a certain amount of hydrophobic substances, including wax, fat, SiO 2 , bamboo film, and others, which will negatively affect the wettability and adhesion of bamboo [ 14 ].…”