In this study, Dendrocalamus asper and Phyllostachys edulis (Moso) bamboo were subjected to a two-phase process of flattening and densification using a non-confined thermo-hydro mechanical (THM) system (composed of two hot plates without lateral limit) to redesign bamboo's microstructure and improve its performance for applications in panel manufacturing. Different softening procedures using pre-treatments with water under vacuum/pressure conditions using a vacuum of −650 mmHg and a pressure of approximately 3100 mmHg (V/P) and boiling treatment for 1 h at 100 °C (B) before flattening were studied. All groups were flattened, dried at room temperature, and densified at the same processing parameters. The microstructural, physical, and bending properties of the obtained flattened-densified bamboo using these two pretreatments were examined and compared with untreated-undensified (UN) bamboo and samples flattened-densified in an equilibrium moisture content (EQ). The results of bending tests, comparing to the un-processed bamboo, revealed that the flattening process combined with densification promote an average increase in the Modulus of Rupture (MOR), (56% and 66%), Modulus of Elasticity (MOE) (48% and 78%), Limit of Proportionality (41% and 86%), and Specific Energy (126% and −12%) in the case of D. asper, and Moso respectively. However, the applied process increased the thickness swelling (SW) and water absorption (WA). This negative effect was more pronounced in the case of Moso compared to D. asper. The flattened-densified Moso using any type of applied pretreatments presented an average of 64% of WA and 35% of SW, while these values for D. asper bamboo were 28% and 19% of WA and SW respectively. In addition, boiling the bamboo in water as a pre-treatment prior to densification reduces the cracks number compared to the other pre-treatments, resulting in higher MOR, MOE, and dimensional stability.

在这项研究中，Dendrocalamus asper和Phyllostachys edulis (Moso)竹子使用无侧限热液机械 (THM) 系统（由两个无横向限制的热板组成）进行压扁和致密化两阶段过程，以重新设计竹的微观结构并改善其在面板制造中的应用性能。使用-650 mmHg的真空和约3100 mmHg (V/P)的压力和100°C煮沸处理1小时的真空/压力条件下使用水预处理的不同软化程序(B)在扁平化之前进行了研究。所有组均被压平，在室温下干燥，并在相同的加工参数下致密化。对使用这两种预处理获得的压扁致密竹子的微观结构、物理和弯曲性能进行了检查，并与未处理的未致密 (UN) 竹子和在平衡水分含量 (EQ) 中压扁致密的样品进行了比较。与未加工的竹子相比，弯曲试验的结果表明，压扁过程结合致密化促进了断裂模量 (MOR) (56% 和 66%)、弹性模量 (MOE) 的平均增加 ( 48% 和 78%)、比例极限 (41% 和 86%) 和比能 (126% 和 -12%) 在D. asper和Moso的情况下分别。然而，所应用的工艺增加了厚度膨胀（SW）和吸水率（WA）。与D. asper相比，这种负面影响在Moso的情况下更为明显。使用任何类型的应用预处理的扁平致密 Moso 平均呈现 64% 的 WA 和 35% 的 SW，而D. asper竹的这些值分别为 WA 和 SW 的 28% 和 19%。此外，与其他预处理相比，将竹子在水中煮沸作为致密化前的预处理可减少裂纹数量，从而提高 MOR、MOE 和尺寸稳定性。