Although synthetic resins play an important role in the
effective utilization of wood resources, from the viewpoint
of recycling or even abolishment of synthetic resins,
binderless boards are considered to be of growing importance.
So far, we have developed binderless boards from
finely ground powder of kenaf core in our previous studies.1
However, the water resistance of the binderless boards was
low and required further improvement. In the study, the
basic principle at issue is self-bonding, which is the main
factor of the board performance expression. Clarification of
the self-bonding mechanism is considered to be important
for designing better manufacturing conditions to improve
the binderless board performances, and for expanding the
possibility of application of the self-bonding mechanism to
other lignocellulosic materials. It has been proposed in
some studies on this subject that furfural generated from
hemicellulose during hot pressing contributed to the selfbonding,
2,3 but the details have not been clarified. In addition,
binderless boards in our study are different from those
in other studies4–9 in that we omitted the steam treatments
such as steam explosion or steam-injection pressing, and
thus their self-bonding mechanism should be examined
separately. Furthermore, in other studies, analyses were
conducted not on the binderless boards but on the pretreated
raw materials of binderless boards.2,5,10 To discuss
the self-bonding factors, analyses on the binderless boards
were required.