Recycling melamine-impregnated paper waste as board adhesives

Melamine impregnated paper offcuts and waste has been shown to be usable both directly, in finely powdered form, as a binder for particle board and as a melamine substitute during the formulation and preparation of liquid MUF resins. Both approaches were based on the residual activity of the MF resin present in the resin. Amounts of waste melamine paper of 22% on dry wood, equivalent to 10% melamine resin solids on total dry panel weight, were shown necessary for water resistant particleboard, and 18.5% for interior particleboard. Due to problems connected to excessive viscosity increase only a maximum of 25% of the total melamine in the formulated melamine resin could be substituted to good effect in the formulation of liquid MUF resin adhesives.