Search Results (3)

Bamboo–wood composites have found extensive applications in the container flooring, furniture, and construction industries. However, commonly utilized bamboo units such as four-side-planed rectangular bamboo strips and bamboo scrimber suffer from either low utilization rates or high adhesive content. The recently developed bamboo-flattening technology, which employs softening methods with saturated high-pressure steam, may improve the utilization rate and reduce the adhesive content, but its complex processes and high cost restrict its widespread application. This study introduces a novel bamboo–wood composite utilizing high-utilization, easy-to-manufacture bamboo units processed through a straightforward flattening-and-grooving method. However, the stress concentration introduced by the grooving treatment may affect the mechanical properties and stability of the bamboo–wood composites. In order to optimize the mechanical properties and bonding performance, response surface methodology based on a central composite rotatable design was used to map the effects of hot-pressing parameters (time, temperature, and pressure) on the mechanical properties. The bamboo-woodbamboo–wood composites prepared with optimized conditions of 1.18 min/mm pressing time, 1.47 MPa pressure, and a 150 °C temperature had a 121.51 MPa modulus of rupture and an 11.85 GPa modulus of elasticity, which exhibited an error of only ~5% between the experimental and model predictions. Finite element analysis revealed that, in comparison to homogeneous flat bamboo composites, grooved bamboo composites exhibited distinct tensile ductility and toughness due to discontinuous stress fields and alternating rigid–soft layers, which alter the stress transmission and energy dissipation mechanisms. Additionally, grooving treatment not only effectively improved the surface wettability of the bamboo plants, thus enhancing the permeability of the adhesive, but also facilitated adhesive penetration into parenchymal cells and fibers. This led to the formation of a more robust glue–nail structure and chemical bonding. Full article

Bamboo, as a renewable biomass material, has received wide public attention. However, due to the thin-walled and hollow structure of bamboo, the mainstream processing method is complex and requires splitting the bamboo into narrow strips and then gluing them together for further manufacturing products. In addition, the surface glue residue makes the safety of indoor applications a concern, especially for cutting boards that come into contact with food. In response to the above problems, this paper introduces a bamboo flattening technology, which can flatten and unfold the pre-treated bamboo into a large-size flattened bamboo board (FBB). The results show that, compared to untreated bamboo, the dimensional stability of the FBB was improved and the flexural strength and elastic modulus of the FBB were increased by about 8.0%. The flattened bamboo cutting board was manufactured with the FBB as the surface layer and had a moisture content and hardness value of 9.2% and 5080 N, respectively, and the accumulated dip peel length of any glue layer was less than 25 mm. The flattened bamboo cutting board is proved to be a carbon-neutral product with a carbon footprint value of −42.92 kg CO₂/t. This work provides a theoretical basis for the fabrication of large-size unspliced bamboo boards and provides new ideas for the scenario-specific application of FBBs. Using a FBB to make cutting boards can avoid contact between food and adhesives, making them more hygienic. The findings of this research can be used to make bamboo cutting boards more hygienic, environmentally friendly and possess excellent physical and mechanical properties. Full article

In this paper, we introduced a bamboo longitudinal flattening technology and analyzed the effects of the softening–flattening process on the physical and mechanical properties of moso bamboo. This is a newer bamboo processing technology that can enhance the utilization and reduce pollution compared with traditional bamboo-based products. Results showed that the parenchyma cells distorted and compacted due to the flattening process. The hemicellulose and cellulose content decreased, while the content of lignin presented an increasing tendency. As expected, the dimensional stability of moso bamboo enhanced due to the decrement of hemicellulose. The softening–flattening process positively contributed to the micro-mechanical properties of treated bamboo specimens. For example, the hardness and modulus of elasticity of the untreated bamboo sample increased from 0.58 and 15.7 GPa to 0.8 and 17.5 GPa, respectively. In addition, the changes in cellulose crystallinity and mechanical properties were also investigated in this paper. The cellulose crystallinity increased from 37.5% to 43.2%, significantly. However, the modulus of rupture of the flattened bamboo board decreased from 9000 to 7500 MPa due to the grooves made by the flattening roller. The MOE of flattening bamboo board showed the same decreasing tendency. Full article