All physical and mechanical properties of particleboards were positively affected by increasing conditioning time of the particleboards. The condensation reactions of the UF resin in the particleboard continues after hot press [21]. For this reason, one day conditioned particleboards had lower IB strength and quality properties as compared with one month conditioned particleboards. The lower quality properties of one day conditioned particleboards than one month conditioned particleboards were mainly attributed to the incomplete condensation of the UF resin. Furthermore, incomplete moisture and temperature conditioning of one day conditioned particleboards could also cause above mentioned quality problems such as lower mechanical properties, higher TS and FE [23] and [24].