Ground wheat straw was procured from the Golestan province, Iran. Straw particles
were chopped beforehand by combine and converted after into smaller particles
with a grinder and then were sieved with a 9/+13-mesh sieve. Urea used for
pretreatment was provided by the Khorasan petro-chemistry company, Iran. This
urea is the same with the two types of UF adhesive used for particleboard manufacturing.
The characteristics of the two types of UF adhesive used in this study are
shown in Table 1.