The reduction of indoor air formaldehyde from wood based composites using urea treatment for building materials

The purpose of this study was to investigate the physico-mechanical properties and characteristics on reduction of formaldehyde from UF particleboards as furniture materials under urea treatment. Straw particle were treated at three levels of urea concentration (5%, 10%, 15%) and 95 °C as holding temperature. Particleboards were manufactured using hot press at the temperature of 180 °C and the pressure of 3 MPa with two types of UF adhesive (UF-45, UF-91). Then the formaldehyde emission values and physical, mechanical properties were considered. The results indicated that the specimens under urea treatment had better mechanical and physical properties in comparison with control specimens. Also specimens manufactured under urea treatment at 10% concentration and UF-91 type adhesive had the most physical and mechanical strength. Furthermore, the results showed that by increasing urea concentration, the formaldehyde emission value was decreased.

► Urea treatment reduced formaldehyde emission, water absorption and increased mechanical properties of particleboard.
► The minimum value of formaldehyde gas emission was measured at the urea concentration of 15%.
► Maximum value of bonding strength was measured at 10%.
► The type of the adhesive affected the formaldehyde emission and physical, mechanical properties of particleboard.