Bamboo is a biomass material, which is a great substitute for wood with the potential to reduce the demand for woody materials. However, there is still a huge challenge to obtain crack-free bamboo boards with an ideal width due to the hollow cylinder and large curvature of bamboo culms. Herein, a method is demonstrated that can flatten bamboo culms by high-pressure saturated steam (180 °C/6 min) under a compression force of 8–10 MPa by two rollers. The macro- and micro-mechanical properties of the flattened bamboo board were also characterized in this paper. Results indicated that the saturated steam had no significant effect on the microstructure of the bamboo, whereas it decreased its hygroscopicity due to the degradation of the hemicellulose. The mechanical properties of the cell walls bamboo samples treated by softening and flattening were elevated compared with those of the untreated ones. During the flattening process, the parenchymal cells became compact. The elastic modulus of bamboo fibers increased from 16.14 to 18.75 GPa, while the hardness increased from 0.58 to 0.77 GPa. The improved mechanical properties of cell walls and increased density had a positive effect on the modulus of elasticity of the bamboo board.

竹子是一种生物质材料，是木材的绝佳替代品，有可能减少对木质材料的需求。然而，由于竹秆的空心圆柱体和大曲率，获得理想宽度的无裂纹竹板仍然存在巨大挑战。在此，展示了一种通过高压饱和蒸汽（180°C/6 分钟）在 8-10 MPa 的压力下通过两个滚筒压平竹秆的方法。本文还对压扁的竹板的宏观和微观力学性能进行了表征。结果表明，饱和蒸汽对竹子的微观结构没有显着影响，但由于半纤维素降解而降低了其吸湿性。与未处理的相比，经过软化和压扁处理的细胞壁竹样品的力学性能有所提高。在扁平化过程中，实质细胞变得紧凑。竹纤维的弹性模量从16.14 GPa增加到18.75 GPa，而硬度从0.58 GPa增加到0.77 GPa。细胞壁机械性能的改善和密度的增加对竹板的弹性模量有积极影响。