A review of preparation of binderless fiberboards and its self-bonding mechanism

The demand for fiberboards has been growing in recent years. However, emission of formaldehyde, which was the main component of adhesives in fiberboards, has caused environmental and health concerns. Industries are therefore pursuing green chemistry technologies to eliminate these concerns. Binderless fiberboards appeared to be such candidates since the manufacturing process involved no resin addition. Several potential mechanisms of the formation of binderless fiberboards have been proposed. Chemical changes of components in lignocellulosic materials were expected to occur, and self-bonding achieved during hot pressing provided main bonding strength. This review summarized various aspects of binderless fiberboard production, particularly feasibility of different raw materials, chemical and enzymatic pretreatments of raw materials, manufacturing process, as well as the potential mechanism of self-bonding. Furthermore, further work that may benefit the elucidation of self-bonding mechanism was discussed.