Study on the Possibility of Using Sunflower Stalk in Particleboard Production

In this study، the possibility of using sunflower stalk for composite-board manufacturing was studied. Density of the boards were 0. 45 g/cm3; variables included mixing ratios of sunflower stalk and industrial wood particles (100:0، 70:30، 50:50، 30:70 and 0:100)، type of resin at two levels of urea formaldehyde and isocyanate (PMDI) or polymeric diphenylmetane 4-4-Diisocyanate، and press-time of 5 and 7 minutes. Thickness swelling (TS) after 2 & 24 hours soaking in water، damping of sound (Damp)، modulus of rupture (MOR)، modulus of elasticity (MOE) and internal bonding (IB) of the boards were measured. The results showed that by increasing sunflower stalk particles، the amounts of TS 2&24، MOR، MOE and IB of laboratory panel were significantly increased. Isocyanate resin reduced thickness swelling after 2&24 hours soaking in water and increased damping of sound as well as modulus of elasticity. Also، urea formaldehyde resin improved modulus of rupture and internal bonding of panels. Press temperature had significant impact on the measured properties. Overall، using sunflower stalk particles up to 70 percent، isocyanate resin، and press time of 7 minutes، could result in producing boards with acceptable physical & mechanical properties which are suitable for interior uses.