How do you determine the vacuum adsorption roller seal

How do you determine the vacuum adsorption roller seal - 2020 06 - 25 zhi-cheng xue Li Yanfeng Li Zhenglu yao qiu-min wu April summary: vacuum adsorption roller seal face geometry parameters, such as the Angle of dynamic and static ring sealing, sealing processing position and the gas film thickness on the opening force, leakage has important influence. Vacuum adsorption roller is mainly used in high precision coating machine, coating machine in working process, vacuum pump suction of vacuum adsorption roller forming local negative pressure, make the object of the coating during the process of traction can firmly adsorbed on the surface of the roll and less prone to offset, to avoid the phenomenon of the membrane material sliding, thus reduce the wear on the surface of the roll surface coating products, so that you can guarantee the printing product surface ( Such as LCD screen, etc. ) The high quality and high precision. 1 seal model is set up in the process of vacuum adsorption working roller, the roller rotates with the moving of the membrane material, sealing strip on roller and installation, roller in the stillness. In order to improve the life and sealing performance of a sealing strip, the seal form for non-contact seal, it is a fixed radial clearance seal, and side clearance can be adjusted and controlled. In order to make the sealing strip have better sealing performance, sealing strip end needs to have a certain Angle between the static ring and ring form convergence fluid film, sealing strip size and Angle of the machining position face Angle will affect the sealing effect. Simplified geometric model of three kinds of gas film cross-section shape as shown in figure 1. Sealing performance 2. Article 1 gas film thickness in a sealed Angle & alpha; , the curvature of the parabola don't change, just change the height of entry for the gas film, the changes of leakage and opening force as shown in figure 2. It can be seen that when the surface of the vacuum adsorption roller linear velocity of 300 m/min, with the increase of film thickness, three kinds of sealing leakage of the model were increased, but open strength were decreased. When gas film thickness at the same time, minimum leakage of model 1, model 2 is the largest. 2. 2 sealing strip processing position assumes that the three models of the thickness of the gas barrier to 0. 2 mm, the result is shown in figure 3. Can be concluded that with the increase of Angle of sealing strip, leakage and opening force increase. In three kinds of sealing models, model 2 is the worst sealing, not be considered. Model 3 by parabolic fluid film layer, leakage and open force are reasonable, but the parabolic model 3 difficult processing, especially when using fluorine plastic sealing material, it is easy to deformation, therefore is not the optimal solution. Minimum of model 1 open force, leakage and model 3 close, can guarantee reasonable leakage, thus confirm the optimal model. 2. 3 sealing Angle through the above comparison, choose model 1 as the research object is analyzed. Under certain Angle of seal, three processing position y reaches ideal seal leakage and gas film thickness values as shown in figure 4. When sealed phase Angle at the same time, the nearer the pressure export processing position, the greater the leakage, and the smaller the thickness of gas film. When sealing Angle increases, the machining position closer to the pressure outlet boundary, the leakage rate will be smaller. When processing position y = - 3. 2 mm, the leakage of the range of 0. 049 - 0. 096 m3 / h, can satisfy the actual requirements of leakage. When sealing Angle of 0. 04 rad, leakage of 0. 072 m3 / h, close to the actual requirements of leakage, the optimal value of 0. 7 m3 / h, so the structure can satisfy the limit pressure and normal work required leakage under pressure. （ Source: packaging engineering)