Properties of oriented strandboard bonded with phenol-urea-formaldehyde resin

Phenol-urea-formaldehyde (puf) resins,based on 14 and 24% urea addition of the resin solid weight,were synthesised in the laboratory and used as binders in oriented strandboards (osbs). the resins were compared with laboratory-synthesised control phenol-formaldehyde (pf) resin. laboratory osbs were made with pf resin and puf resins at two resin solid levels (3.5 and 4.5%). the properties of osbs made using pf and puf resins were evaluated. performance tests showed that mechanical strength properties decreased with increasing urea addition,while dimensional stability increased. all osbs showed good physical and mechanical properties. © forest research institute malaysia.