Study on the mechanism of inhibition of bagasse fibres hornification by microwave bulking

Using bleached, undried bagasse pulp as raw material, this study investigated the inhibitory effect of microwave expansion on secondary fibre hornification. The optimal process parameters were determined through optimisation: microwave power: 900 W, temperature: 70 °C, duration: 2 min, solid-liquid ratio: 1:10, and expansion agent dosage 10 %. Results demonstrated that this treatment significantly enhanced fibre water retention and paper strength. Water retention of reused bagasse fibre increased by 18.89 % after a single reuse and remained elevated by 6.34 % after five reuses. Mechanistic analysis revealed that microwaves disrupt inter- and intramolecular hydrogen bonds in cellulose, reducing crystallinity, microcrystal size, and primary fibre cross-sectional area while disintegrating pseudocrystalline regions. This inhibits hornification, providing theoretical and technical support for efficient reuse of non-ligninous fibre.