The Study On Mechanism Of Hot Pressing-binder Mixture Molding Of Corn Stalk Biomass

For the postgraduate material hot pressing-binder mixture molding mechanism,this paper uses corn stalks as the experiment material,and anhydrous powdered bagasse,corn starch,wheat starch and tapioca starch as the binder.A three-factor five-level orthogonal experiment was designed based on the binder adding mass ratio,the heating temperature of the forming sleeve,and the moisture raw material.The binder adding mass ratio is set to 2%,4%,6%,8%,10%,the heating temperature of the forming sleeve is set to 60,80,100,120,and 140°C,and the raw material moisture is set to 10%,12%,16%,20% and 24% respectively.Using the analysis of variance method,the relaxed density,surface quality and shatter resistance of each molding block are affected by the different binder adding mass ratio,the different heating temperature of the forming sleeve,and the different raw material moisture.The experiment results were analyzed for the best parameters,and a verification experiment was performed to verify that the results of the best parameter analysis were more accurate.Conducted analysis and comparison of molding power consumption and overall energy consumption.Energy consumption experiments were carried out on biomass room temperature-binder molding,biomass hot pressing-binder mixture molding and biomass hot pressing molding without adding binder.The verification conditions are that corn stalks are used as the raw material for biomass molding,and anhydrous powdered bagasse,corn starch,wheat starch and tapioca starch are used as binders,and using self-made hydraulic plunger molding machine as experiment equipment.It is found that the overall energy consumption of biomass hot pressing-binder mixed molding is less than the overall energy consumption of biomass room temperature-binder molding which can save 3%-6% of overall energy consumption and the overall energy consumption of biomass hot pressing-binder mixed molding is less than the biomass hot pressing molding without adding binder which can save 6%-9% of overall energy consumption,which can provide reference for follow-up research.The range analysis method is used to analyze the degree of influence of the center point temperature,maximum temperature,average temperature and minimum temperature of the cross section of the molding block in each experiment by the binder adding mass ratio,the heating temperature of the forming sleeve and the raw material moisture.The multivariate overall model of each dependent variable is obtained by curve fitting.Taking the center point temperature,maximum temperature and average temperature of the cross section of the molding block as independent variables,taking the shatter resistance of the molding block as the dependent variable,using Excel software to perform multiple regression analysis of the primary,secondary and cubic models.And the multiple regression equation is obtained.Finally,it was found that the cubic model fits best which fitting degree is greater than 0.8.A stereo microscope was used to observe the microscopic images of the center of the cut surface and the edge of the cut surface of the corn stalk molding block.It can be found by comparison that the bonding between the materials at the periphery of the cut surface is closer than that at the center of the cut surface.Using heating means can better promote the softening of the binder,which is conducive to molding.Adopting the method of adding binder can enhance the bonding effect between materials and better promote the molding.