Study On The Fiber Separation Mechanism Of MDF And The Optimization Design Of Plate-bar Structural Parameters

Medium density fiberboard (MDF) is one of the most important wood-based panels, because of its excellent physical and mechanical properties, it was widely used in the industry of engineering construction and interior decorating, etc. Thermomechanical refining process a very important during the whole process and the key factor that affects the refiner performance and potential lies in the refining plate. Whether the parameters of plate tooth structure are reasonable will directly affect the separation quality of fiber and the energy consumption. Study on the influence that the parameters of plate tooth structure on the move status and separation quality of fiber, reveal the fiber separation mechanism and optimize the parameters of plate tooth structure can help to establish a more complete fiber separation theory, improve the design level of refiner disk and can help to the energy-saving during fiberboard production.According to the basic principle of fiber separation and technical process of fiber preparation, combining with the parameters of plate tooth structure, this paper analyzed and studied the action mechanism of different refining zones to fiber separation; Combining with analysis of the influence that the parameters of plate tooth structure on the action mechanism of fiber separation, this paper expatiated the optimization design of the parameters of plate tooth structure.The move status of fiber in refining zones determine the residence time, thus have a great influence on the separation quality of fiber and the energy consumption. According to the fiber operation condition, through the analysis of forced state of fiber in gap, this paper established the mechanical model of fiber, and then the solved the trajectory of fiber and made clear the influence that the parameters of plate tooth structure on the move status of fiber, described the action mechanism of parameters of plate tooth structure from kinematics.Through the analysis of the change of raw materials’size and shape during refining, combining with the character of plate tooth structure in different zones, this paper studied on the action mechanism of each zone, made clear the influence that the width of groove, the bar angle, the dam and the refiner disk taper on the action mechanism of refiner disk, established the relation between mechanism of fiber separation, laid a theoretical foundation for the optimization design of the parameters of plate tooth structure.Through the experimental study on the influence that the raw materials on the separation quality of fiber, this paper analyzed the influence that the proportion of soft-wood and hard-wood and the content of bark on the separation quality of fiber, which provided a basis for the reasonable selection of raw materials; Through the experimental study on the influence that the parameters of plate tooth structure on the separation quality of fiber, this paper compared and analyzed the influence that the difference in parameters of plate tooth structure on the separation quality of fiber, found the key factor affecting on the separating state of fiber and the action mechanism of the parameters of plate tooth structure was verified.Based on the results above, combining with the production experience, this paper expatiated the optimization design of the parameters of plate tooth structure, discussed the theory and method of optimization design, analyzed the problems needing attention during optimization design and which provided guidance for the optimization design of the parameters of plate tooth structure.Study on the action mechanism of refiner disk to the fiber separation process and the optimization design of the parameters of plate tooth structure further improved domestic study on fiber separation mechanism, provided a new idea and method for the optimization design of plate-bar structural parameters, all of these can help to improve the quality and reduce the production cost of fiberboard and can help the rapid and healthy development of the whole fiberboard industry.