Research on urea- formaldehyde resin adhesive agent of low free formaldehyde content

The free formaldehyde of the urea formaldehyde resin adhesive agent is the main pollution source of artificial board.The urea formaldehyde resin with lower content of free formaldehyde could be prepared by adopting the techniques of decreasing formaldehyde/urea molar ratio,charging urea in three times and adding PVA as modifier.The concentration of free formaldehyde of the resin was 0.4% and reduced to 0.1% after one week,it is fully adequate to meet the demande of the environmental protection.This process is simple and lower cost.