Abstract:

The internal bonding strength (IB) of board made of laccase-reacted fibers (Pinus kesiya var. langbianensis),water-treated fibers,inacted laccase-treated fibers was compared.It was found that the internal bongding strength of fiberboards made from laccase-reacted fibers at pH 3.0,3.5,4.0,4.5, and 5.0 was markably higher than that from water treated ones and inactivated laccase-treated one.Therefore,the laccase activation of wood fibers and the contribution of laccase(EC 1.10.3.2)reaction to the auto adhesion of wood fibers were observed in the laboratory experiments.The main factors that effect on activation and adhesion,such as pH,dosage of laccase,the concentration of substrate and time for activation,were investigated through the test of IB.The fiberboard made under the optimal activating and hot-pressing conditions had desired internal bonding strength of higher than 1.0 Mpa.

Key words: Laccase, Activation, Lignin, Wood fibers, Auto adhesion