Pneumatic Molding Mechanism And Experiment Research On Straw-based Nutrient Seedling-growing Bowl Tray

The technique of rice transplanting and seeding-growing tray made of paddy straw is one of the effective ways to solve the problem of the quality and yield of rice in the north cold area.However,the current seeding-growing tray made of paddy straw need a lot of soil and efficiency of breeding is low,the tray molding process has problems such as high energy consumption and mold life is short.The study was conducted by the 2017 national basic level agricultural technology extension subsidy project”Cold Region Rice Quality Improvement Technology Integration Promotion”(JCTG17-03)and land reclamation bureau of science and technology project “Test and Demonstration of Mechanized Cultivation Techniques for Rice Seeding-Growing Bowl Tray”(HNK135-03-02),to realize the ecological cycle agriculture and sustainable development agriculture as the starting point,the aim is to improve the quality of breeding and to achieve the utilization of straw resources,designed the straw-based nutrient seedling-growing bowl tray,research on the pneumatic forming mechanism,raw material ratio,and molding process has also been carried out in depth.The details are as follows:(1)The concept of seedling cultivation of bowl tray and the concept of value-added use of rice straw were combined to propose the concept of nutritive rice straw potted tray.Under the premise of meeting the agronomic requirements for rice breeding and transplanting,from the perspective of potted tray strength and applicability,theoretical analysis and experimental studies were carried out to determine the structural form and main parameters of the potted tray.Compared to plastic trays,it has the advantages of no root damage and no rejuvenation stage.Compared to early seeding-growing tray made of paddy straw,he efficiency of childbearing has been significantly improved.(2)Based on the study of the pneumatic forming mechanism,a pneumatic forming process is proposed,straw-based nutrient seedling-growing bowl tray forming machine was developed.FLUENT software was used to optimize the structure of the mold,the optimal structure dimensions were confirmed,and verified the accuracy of simulation results through experiments.Combined with intelligent control technology,a pneumatic forming testbed was developed to provide a platform for research on the ratio and technology of rice straw nutrition tray raw materials.(3)In order to determine the optimum material ratio of nutritive rice straw potted tray,four-factor five-level orthogonal rotation combination test was conducted,with pneumatic forming testbed was used as a test platform,slurry concentration,pulp content,adhesive quality,and straw to cow dung mass ratio was used as variable,taking pot rate and strong seedling index as evaluation index.The response surface analysis method was applied to optimize the results and finally determined the optimum raw material ratio of the straw-based nutrient seedling-growing bowl tray.(4)In order to explore the optimum molding process parameters of the straw-based nutrient seedling-growing bowl tray,the straw slurry made from the optimal ratio was used as the raw material,pneumatic forming machine was used to prepare the nutritive rice straw potted tray.Using ternary quadratic regression orthogonal rotation combination test and response surface analysis method,the influence of three forming factors of forming mold vacuum degree,adsorption time and dwell time on the three molding specifications of pot rate,loose density and breaking strength were studied,the best molding process is obtained.(5)On the basis of the straw-based nutrient seedling-growing bowl tray forming machine,straw-based nutrient seedling-growing bowl tray production line was set up.According to the optimization of the optimal ratio of raw materials and the best molding process to achieve the industrial production of straw-based nutrient seedling-growing bowl tray.Field comparative experiments has been conducted from four perspective of seedling emergence rate,seedling quality,yield and benefit,as the prepared nutritive rice straw potted trays and conventional plastic trays were used as breeding carriers,the root nets and plastic membranes were used as barrier materials.Straw-based nutrient seedling-growing bowl tray pneumatic molding process is proposed innovatively base on pneumatic forming mechanism,the corresponding molding equipment was developed.The optimum raw material ratio and best molding process for production of trays was obtained through experiments,the preparation technology of rice straw nutrition trays was clarified and finally verified by production tests and field tests.The research results provide the preconditions and theoretical basis for the standardized production of rice straw nutrition trays.