| Abstract:Stem is an important skeleton raw material for the base sheet of papermaking-process reconstituted tobacco. Its cell wall structure is compact, and the fibers are short and brittle. Direct refining tends to increase fine components, which adversely affects the base sheet''s strength, bulk, and coating adaptability. Appropriate pretreatment can promote the swelling and softening of stems, weaken the bonding between cell wall components, and reduce the resistance to fiber separation and refining. Focusing on the demand for high-efficiency, low-energy flexible refining, this paper reviews the mechanisms, process characteristics, and effects of various technologies for stem pretreatment, including hydrothermal/steam pretreatment, steam explosion, microwave expansion, screw extrusion, disc coarse refining, and biological enzyme treatment. By analyzing their synergistic relationship with modern pulping equipment such as high-consistency fiber separation and low-consistency refining, the paper proposes a development direction for efficient tobacco stem refining through the synergy of combined pretreatment and modern pulping and papermaking equipment. This lays the foundation for constructing a synergistic process technology route of “pretreatment regulation-high-consistency flexible fiber separation-low-consistency refining”, thereby promoting the development of tobacco stem pulping toward low damage, low energy consumption, and high quality. |