Urea-formaldehyde resin (UF) is a thermosetting plastic formed by the condensation polymerization of urea and formaldehyde. It can be regarded as the “universal glue of the wood industry” - it forms a cross-linked network through the rapid condensation of cheap and readily available urea and formaldehyde, thus having extremely low production costs, good hardness and heat resistance (but poor water resistance and aging resistance). It not only has high bonding strength but also can deeply composite with wood fibers, and is widely used as a bonding agent for artificial boards (plywood, particleboard, medium-density fiberboard), electrical enclosures, sockets and switches, as well as in daily life such as buttons.