Preparation of and study on environmental protection urea-formaldehyde resin adhesive and plywood

The effect of modification of urea-formaldehyde(UF) resin and production technology of plywood on the amount of formaldehyde emission were studied.The modification method concerned mainly with adopting dehydration technique and using modifiers.The production technology of plywood concerned mainly with types of modifier and the preparation condition.The research showed that low free formaldehyde and high adhesion strength were obtained by adopting dehydration technology and adding modifiers.The amount of formaldehyde emission of plywood was declined obviously by using modified urea-formaldehyde resin adhesive.Increasing the pre-pressing time and hot pressing time can effectively reduce the amount of formaldehyde emission of plywood,and the amount of formaldehyde emission was cut down at first and then raised when the hot press temperature increase.The analytic study was also made on molecular structure of urea-formaldehyde resins.