Study Of Producing UF-G Low Toxicity And Powder Urea-Formaldehyde Resin

The paper has been summarized the production and application status of urea-formaldehyde resin and analyzes the research advance of urea-formaldehyde resin in the domestic and international research. On the basis of many single-factor experiments the formula of low toxic and powdery Urea-Formaldehyde resin adhesive,synthesis technology and drying technology are thoroughly discussed.Considering technology and performance requirements of low toxic and powdery Urea-Formaldehyde resin adhesive, the single factor optimizing test that the choice of molar ratio,control mode of pH,feeding mode,categories and addition of the reinforcer, is carried out.On the basis of testing results the formula and synthesis technologic parameter of UF-G Low Toxicity and liquid Urea-Formaldehyde Resin Adhesive that molar ratio F/U=1.2:1; at the stage of acid,in the first stage pH value in the range of 4.8～5.0, in the second stage pH value in the range of 5.4-5.8; secondary batching of formaldehyde triple batching of urea; the complex strengthening agent what is taken melamine and metal salt as the main body is made out. And the appropriate content of strengthening agent is 5%.Finally,preparation of high quality liquid adhesive, which can be used to product the UF-G Low Toxicity and liquid Urea-Formaldehyde Resin Adhesive, by reasonable control of addition amount of strengthening agent,reaction temperature and reaction time.Through the study of the temperature of drying medium and drying time in laboratory, the results show that control the range of the temperature of drying medium from 170 to 190℃and the drying time form 4 to 6 seconds can obtain UF-G Low Toxicity and liquid Urea-Formaldehyde Resin Adhesive with the satisfactory index of physicochemical properties.Moreover, the performance test of the application of UF-G Low Toxicity and liquid Urea-Formaldehyde Resin Adhesive in the floorboard and MDF are offered. the results of the test showed that the formaldehyde emission meet El-class of European standards and the all other properties meet the requirements for national standard of China.