Mechanism analysis of mechanical extraction of Pleioblastus amarus fibers by saturated steam pretreatment

Currently, bamboo fibers (BFs) are commonly processed through alkali boiling softening pretreatment, which generates wastewater that poses environmental pollution risks. This process is also complex and requires significant human and material resources. In contrast, the saturated steam softening pretreatment method studied in this study is environmentally friendly and significantly simplifies the post-processing of bamboo fiber preparation. Additionally, it provides methods and parameters for the hygrothermal-mechanical extraction of bamboo fibers. In this study, three-year-old bitter bamboo (Pleioblastus amarus) growing in Zhongtai town, Yuhang district, Hangzhou city, China was selected as the raw material. Firstly, bamboo fibers were prepared by crushing and mechanical extraction after softening through alkaline boiling and saturated steam pretreatment, respectively. The yield, mechanical properties, and other indicators of the fibers were then tested and compared. Subsequently, Scanning electron microscopy (SEM) was employed to observe and comparatively analyze the microstructural morphology of the two types of fibers. Infrared spectroscopy (IR) was performed on the functional groups of bamboo after alkali boiling and saturated steam softening to investigate changes in cellulose, hemicellulose, and lignin. Finally, the mechanism of mechanical extraction of bitter bamboo (Pleioblastus amarus) fibers by saturated steam pretreatment was further analyzed.