Abstract: The tea waste powder with different sizes as an additive was used to urea-formaldehyde (UF) resin, and the effects of the tea waste powder sizes and amount on the free formaldehyde content of UF resin, the formaldehyde emission, and bond strength of UF resin bonded plywood were studied in this paper. The experimental results indicated that the tea waste powder as an additive to UF resin could reduce its free formaldehyde content and reduce the formaldehyde emission of UF resin bonded plywood; the tea waste powder with much less size was easily mixed with UF resin and acted much more effective; the tea waste as an additive to UF resin in a proper amount did not decrease the bond strength of plywood.

Key words: Urea-formaldehyde resin adhesive, tea waste, free formaldehyde content, formaldehyde emission, bond strength