Erkan Avci

Evaluation of the physical, mechanical properties and formaldehyde emission of particleboard manufactured from waste stone pine (Pinus pinea L.) cones

The objective of this study was to investigate some physical/mechanical properties and formaldehyde emission of particleboard containing particles of waste stone pine cone at various usage ratios using urea-formaldehyde resin. Some physical (thickness swelling, water absorption), mechanical (modulus of elasticity, modulus of rupture, internal bond strength) properties and formaldehyde emission of particleboards were evaluated. The addition of cone particle improved water resistance of the panels and greatly reduced their formaldehyde emissions. However, flexural properties and internal bond strength decreased with increasing cone particle content in the panel. The cone of the stone pine can be considered as an alternative to wood material in the manufacture of particleboard used in indoor environment due to lower thickness swelling, water absorption and formaldehyde emission.

Utilization of Waste Tire Rubber in the Manufacturing of Particleboard

Utilization of waste tire rubber in the manufacture of particleboard was investigated, using the same method as that used in the wood-based panel industry. The manufacturing parameters were: a specific gravity of 0.65 and waste tire rubber content (10/90, 20/80, and 30/70 by wt% of waste tire rubber/wood particle). Two resin types, melamine/urea formaldehyde (MUF) and polyisocyanate, were used in the experiments. Average modulus of rupture values of MUF bonded particleboards with rubber crumbs were between 13–58% lower than the average of the control samples while polyisocyanate bonded particleboards were 12–51%. Water resistance of the boards improved with the increase in rubber crumb/wood particle ratio. Thickness swelling values of the MUF bonded particleboards decreased from 14–53% while polyisocyanate bonded particleboards were 9–48% as compared to control samples.

Utilization of waste tire rubber in manufacture of oriented strandboard

Some physical and mechanical properties of oriented strandboards (OSBs) containing waste tire rubber at various addition levels based on the oven-dry strand weight, using the same method as that used in the manufacture of OSB. Two resin types, phenol-formaldehyde (PF) and polyisocyanate, were used in the experiments. The manufacturing parameters were: a specific gravity of 0.65 and waste tire rubber content (10/90, 20/80 and 30/70 by wt.% of waste tire rubber/wood strand). Average internal bond values of PF-bonded OSB panels with rubber chips were between 17.6% and 48.5% lower than the average of the control samples while polyisocyanate bonded OSBs were 16.5-50.6%. However, water resistance and mechanical properties of OSBs made using polyisocyanate resin were found to comply with general-purpose OSB minimum property requirements of EN 300 Type 1 (1997) values for use in dry conditions at the lowest tire rubber loading level (10%) based on the oven-dry panel weight. The tire rubber improved water resistance of the OSB panel due to its almost hydrophobic property. Based on the findings obtained from this study, we concluded that waste tire rubber could be used for general-purpose OSB manufacturing up to 10% ratio based on the oven-dry panel weight.