Plywood product quality improvement veneer glue

At present, the adhesives used in the production of plywood mainly include PF phenolic resin and UF urea formaldehyde resin, among which urea-aldehyde resin is the major one. The curing agent used to modulate UF resin is mostly NH4CL, and the amount is 0.4-1% of UF resin quality. In order to achieve the appropriate active time and curing time, the required active time of glue is 6-8 hours. In summer when the temperature is high, buffer and curing agent can be used to prolong the glue activity. PF adhesive is used Before adding curing agent, but if you can add fillers and copolymers, you can improve the toughness and strength of the adhesive layer in the sizing, the current domestic use of roller sizing, mainly to take its technology is mature, simple structure Characteristics, but the early double-roller sizing, glue volume is not easy to control, low efficiency, if the use of four-roller sizing machine, can improve the uniformity of sizing and control the amount of sizing.