IntroductionIn recent years, as people on environmental protection, health awareness, as well as the sustainable development of wood processing industry, protein-based adhesives renewed attention. Soy protein rich, low cost and contains a large number of active groups to produce soybean meal and soybean protein gel has great potential [1]. Soy protein adhesives have been used in plywood manufacturing in the United States [2], 2005, China has also achieved the soy protein plastic plywood for industrial production [3], 2006, Nanjing Forestry University, a patent application for "non-formaldehyde-speed business bean gum Yang Ⅱ Plywood production method for industrial production "[4], in 2009 in Shandong Province of the soybean protein fiber in the industrial production of glue [5]. The results show that urea concentration on the unfolding of tertiary structure of soy protein have a significant effect, and the use of urea to the modification of soy protein than with alkali modification, has better water resistance [6,7]. Ultrasonic treatment is widely used in various studies, particularly ultrasound can accelerate the chemical reaction [8]. Currently, soy-based adhesive is mainly used in wood processing industry, less adhesive applied to this experiment, ultrasonic urea modified soy protein powder, preparation of soybean protein adhesive, adhesive cardboard; system protein concentration, urea concentration, treatment time, temperature, ultrasonic treatment time on the soybean protein gel adhesive strength. This experiment soy-based adhesives Pan-wide application provides a new way of 's thesis, expert help translate what wow, reward high scores, just to the exact translation:) good answer double extra points。绝对新