The hardener type was found to be effective all of the properties
of particleboard. The pH of the wood particle with the urea was slightly higher than that of particles without
urea.
The lowest pH value for the resinated wood particles was obtained from ammonium chloride, followed
by ammonium sulphate and aluminium sulphate, respectively. The best quality properties were obtained
from the particleboards manufactured with ammonium chloride, followed by particleboard made with
the ammonium sulphate and aluminium sulphate, respectively. The urea usage significantly decreased
the formaldehyde emission of the particleboards while it slightly decreased the mechanical properties
and increased thickness swelling. Increasing conditioning period of the particleboards from one day to
one month improved the quality properties.