Molding Mechanism And Experimental Research On Seedling-growing Tray Made Of Rice Straw For Maize Seedling Transplantation

The technique of maize transplanting and seedling-growing trays is one of the effective ways to solve the problem of the quality and yield of Maize in the north cold area,but the adaptability of the seedling-growing trays and transplanting technique is poor.Therefore,according to the maize seedling-growing trays transplanting technology development needs,independent research and design maize transplanting seedling-growing trays,using the method of theoretical analysis,simulation and experimental research,and explored deeply from the design and manufacture of seedling-growing trays,compression molding and drying curing etc..(1)According to the agronomic requirements of maize transplanting seedling-growing trays,and demand of mechanization planting operation,research to determine the preparation main material and other auxiliary materials of seedling-growing trays,according to the nature of material preparation,determine the trays equipment through comparative analysis and design the preparation process.(2)Research on design the idea of seedling-growing trays,design structure of the seedling-growing trays,build mold three-dimensional model using UG NX8.0 software,simulation analysis on molding parts of tray mold manufacturing and molding equipment supporting connection through NX NASTRAN and ANSYS UG solver.(3)Comprehensive analysis forming mechanism of the biomass materials molding in hot press and powder material molding in normal temperature and high pressure,study the trays material compression molding process,establish the creep equation of the forming material in the actual compression state and the expression of viscous elastic plastic axial strain in the compression molding of the bowl shaped material in three dimensions,reveal the mechanism of compression molding,Analysis to determine the evaluation of the performance of seedling-growing trays.Using PROE software to establish the three-dimensional model of the trays,and the ANSYS WORKBENCH module was used to simulate the stress and deformation of the trays.Determining the position of the cutting tray and the cutting structure,obtaining better cutting effect.(4)Select the preparation proportion of seedling-growing trays material composition for single factor test,analysis the effect the trays forming rate,fracture rate,bending strength,compressive strength,maximum shear stress and the rate of expansion.Based on the results of single factor experiment,select the factors trays molding pressure,rice straw and reinforced matrix mass ratio as the factors,molding rate,swelling rate,bending strength,shear stress of seedling-growing trays as the performance index,carried out the two orthogonal rotating combination experiment of three factors and five levels.Establish regression equation of each factor and the performance index,to investigate the influence of various factors on the performance index,the regression analysis showed that the influencing factors on performance index,through the main objective function method,using Design-Expert Version 8.0.5 software,carried out the analysis of regression equation of performance optimization,confirm the optimal combination of parameters,through verification test,the performance indicators meet the requirements of maize seedling and transplanting.(5)Analysis the heat and mass transfer mechanism,drying curve equation and dynamic equation in drying stage of superheated steam drying and curing trays,revealing trays drying and curing molding mechanism.On this basis,the drying time,the steam temperature and the superheated steam mass flow were selected as the factors to analyze the influence on the dry strength,wet strength and drying rate.Then select the drying time,the temperature of superheated steam and the steam mass flow rate as factors,dry strength and wet strength and wet basis moisture content as the performance index,carry out the orthogonal rotation combination test of three factors and five levels.Establish regression equation of each factor and the performance index of the trays,to investigate the influence of various factors on the performance index,the regression analysis showed that the influencing factors in performance index,through the main objective function method,using Design-Expert Version 8.0.5 software,the regression equation of performance optimization analysis,the optimal combination of parameters.The performance indicators meet the requirements of maize seedling and transplanting through verification test.(6)Test the change of shear mechanical properties for the tray in the cutting rate,obtained in the same cutting rate under different straw quality than the trays shear the change of mechanical properties at different cutting speed,the same quality than the straw bowl shear mechanical properties variation,trays preparation and use of three point shear stage performance changes,provide a theoretical basis for the design of motion parameters of transplanting machinerotary device.By the experiment of seedling transplanting verified the quality of seedling raising and transplanting effect.