Sundri wood chips were subjected to a mild chemical pre-treatment
by soaking them in 1,2 and 3% solutions of NaOH and NaiSCh,
individually as well as in mixture, for 24 hours at atmospheric conditions.
Hardboards made from pre-treated chips were tested for determining
their strength and water resistance properties. It was observed
that the boards made from the chips pre-treated with NaOH alone
and in mixture with Na2SO3 were stronger than those made by simple
steam softening of the chips prior to refining. Also the strength of
the hoards increased with an increase of the concentration of the pretreatment
solutions. Pre-treatment with NaOH alone produced stronger
boards than with the mixtures. Any such effect on the strength
property of the boards, however, was not obvious in the pre-treatment
with Na2 SO3 solutions. AU the pre-treatment methods adversely
affected the water resisting properties of the boards.