The experiment designed as factorial using completely randomized
design arrangement. Duncan method was used to compare
means (P < 0.05). Statistical analysis was conducted in SPSS. The
combination of parameters in MDF production were produced 36
MDFs for our study (Table 1). Urea–formaldehyde adhesive (Table
2) was purchased from chasbsaz, Inc. (Sari, Iran). The adhesive levels
were 9% and 11% by weight. Canola straw (Fig. 1) was obtained
from canola fields in the north of Iran (Sari, Mazandaran). Determination
of fiber dimensions were carried out based on Franklin
method. Fibers from canola straw were processed at the Wood Science
and Technology Department, University of Tehran. The raw
straw was chopped by laboratory chopper and then soaked in tap
water for 1 h. Then the soaked straw was steamed at steaming
times of 2, 5 and 8 min. The pressure and temperature of steam
was 8 bar and 170 C, respectively. The steamed straw was then
pulped by using a laboratory atmospheric refiner. The pulps were
gradually collected and pre-dried. The drying process was completed
in a convective oven at 100 C. After drying, the dry-basis
moisture content of the fibers ranged from 2% to 3%.