In order to enhance the performance of the epoxy resin-prepared materials, straw fiber was used as the reinforcing base in this study. The principle of this study is to use the cellulose component exposed after the defibrillation of straw fiber can be further combined with the epoxy group. Firstly, the degree of defibrillation of straw fiber under three different pretreatment methods of acid, alkali and moist heat treatment was explored, and a control test was conducted with untreated straw fiber, which showed that the defibrillation of the straw fiber after alkali treatment was better than the other two methods. Secondly, to prove the comprehensive effect of the pretreatment method and straw fiber filling amount on the composite material performance, this paper carried out a tensile, bending, density and water absorption test. The results showed that when the straw fiber filling was 15%, the best performance of the composites was achieved by the alkali treatment, with tensile strength and tensile modulus reaching 1.89 KN and 3.92 MPa, bending strength and bending modulus reaching 2.00 KN and 81.65 MPa, average water absorption reaching 2.77%, and density reaching 0.957 g/cm³. Finally, the results were verified using Image J software was used for verification. After comparison, the material meets the basic requirements of high-density fiberboard material and provides a reference for preparing straw epoxy resin composites.

In the comprehensive development and utilization of crop straw, it is key to separate the fibers in the straw through a certain process or equipment. In order to obtain rice straw fiber material, the straw fiber crusher was designed using SOLIDWORKS software, and its grinding process was simulated using EDEM software to verify the feasibility of the machine principle and structural rationality. The grinding wheel speed, screw feed shaft speed, and grinding wheel clearance were used as test factors to design a three-factor, five-level test using Design Expert 13, obtaining a grinding wheel speed of 1250 r·min⁻¹, a screw feed shaft speed of 40 r·min⁻¹, and a wheel clearance 0.21 mm, which can achieve a theoretical kWh output of 45.8 kg/(kW·h) and a tensile index of 112.5 N·mg⁻¹. We aimed to establish a model of the pore channel of the specimen, analyze the characteristics of the model within the unit area of different specimens, investigate the intrinsic relationship between the tensile index and the image pore channel coefficient of the straw fiber specimen, and to verify the feasibility and rationality of using the tensile index to evaluate the quality of straw fiber.

As a new type of agricultural waste block substrate utilization, the initial wet base state of the substrate culture block needs to be dried. Therefore, studying the drying mechanism of substrate culture block is critical. In this study, the substrate culture block in a dry state was taken as the research object. Based on physical and chemical properties, the internal section of the substrate culture block was characterized by scanning electron microscopy and the pore condition of the particles was quantified. The results showed that the internal pore structure was uniform and favorable for plant root growth. Based on the pore structure, pore channel modeling was constructed to investigate the distribution of the internal multiphase medium and to distinguish between channels and pore-blind channels. The applicability of the modeling was verified and discussed. By measuring the drying rate of the substrate culture block and classifying its drying stages as fast speed, constant speed, and slow speed, it is clarified that the forms of moisture existence are bound-state water and free-state water, and the moisture migration is prioritized as surface adsorption water, interparticle water, particle attached water, and capillary water. Innovate a method to quantify the change of pore space in the drying process by pore coefficient ratio to evaluate the drying quality. The results show that when the pore coefficient ratio is about 40 %, its moisture content is 20 %∼30 %, and the drying effect is best at this time. The physical drying test further confirmed the correctness of the conclusion of the drying stage division and water loss law. This study can provide a theoretical reference for the modeling study of the pore structure of the block matrix and the exploration of its drying mechanism.

After corn straw and livestock manure are fermented and decomposed, grass seeds are added. The substrate grass seed blanket is made by screw extrusion, applied to park greening, square greening, protective greening, and residential area greening. With this device, the purpose of reducing the labor force and improving space utilization rate can be achieved. The working principle of the substrate grass seed blanket extrusion device is mainly described, and the extrusion process is analyzed including: compaction and filling stage, surface deformation and compaction stage, plastic deformation stage, and molding stage. The main experimental factors are determined through theoretical analysis of screw size and working parameters, including screw pitch, screw length, screw diameter, and screw speed. Using the EDEM simulation analysis method, taking the quality of extruded particles and the uniformity of grass seed mixing as test indexes, and under the condition of the same extrusion time of 30 s using Design-Expert software to carry out an orthogonal quadratic rotation combination test, a significant regression model was obtained. The effects of different parameters and extrusion conditions on grass seed blanket forming influence were studied by response surface analysis. The optimal working parameters were obtained: screw speed 250 r·min⁻¹, screw pitch 120~80 mm, screw diameter 240 mm, and screw length 400 mm. With the same extrusion time of 30 s, extruded pellet mass was 2620 g, calculated mass flow rate was 131 g/s, and the grass seed mixing uniformity was 92.35%. Under the optimal simulation conditions, the prototype was manufactured, and the actual verification test was carried out. The errors between the measured values of extruded substrate quality and grass seed mixing uniformity and the simulation test results were 3.4% and 2.5%, respectively, which met the requirements of the grass seed blanket extrusion molding device.