4. Conclusion
Binderless boards were manufactured from rice straw by hotpressing
and measured for IB, TS and WA in order to evaluate the
morphological effect on the properties of the board. For the morphological
effect, we examined the influence of particle size and
morphological part. Our conclusions are summarized as follows:
1. Binderless boards were successfully manufactured from rice
straw when the raw materials were ground until they passed
through 1-mm screen.
2. For the effect of the morphological part, the IB of boards made
from stem powder was the highest, followed by leaf blade powder
and leaf sheath powder. IB increased with decreasing ash
and silica contents. Trichomes and wart-like protuberances on
the epidermis of rice straw might inhibit self-bonding between
particles.
3. The water resistance of binderless boards made from rice straw
was relatively high regardless of low IB. Wax-like substances
on the epidermis of rice straw contributed the water resistant
properties of particles.
4. This study suggested that binderless board made from rice straw
was one of the best methods to fully utilize the potential of rice
straw, in contrast to boards made with UF resin that suffer from
low compatibility between the resin and wax-like substances on
the epidermis of rice straw.