Study On Structure Optimization For Synchronization Bidirectional Stretching System Of BOPP Film

The plastic film has become one of the largest production and the most varieties of plastic products in China, In existing technology the transverse and longitudinal tensile are respective, Lead stretching ratio、film thickness uniformity and the properties of the films to control difficultly in the relevant parameters. Based on absorbing the domestic and foreign film step transverse and longitudinal tensile, tensile equipment technology of the synchronization, accessory modeling by means of 3D software for the related parts, based on it to complete motion simulation, research the track and stretching chains of the synchronization control bidirectional stretching machine, and optimize the track design. To solve the existing problem of tensile equipment of film thickness, in order to improve the tensile properties of thin film.This paper according to the principle and structure of Synchronization control bidirectional stretching machine and simplifying the model of stretching chains. Abstract the crank slider mechanism and analysis to it. According to the motion principle of a standard crank mechanism and establishing the motion equation by D-H method. The software ADAMS is used to build a three-dimensional model and make a dynamic simulation. The Displacement, velocity and acceleration of the standard crank mechanism are gained. The dynamic simulation results show the Reasonableness of the standard crank mechanism and the Relationship between agencies of operation. Thus we can design standard crank mechanism flexibly to meet the needs of a variety of mechanical devices, and simplify the design of the device. According to the motion principle of a standard crank mechanism and establishing the motion equation by D-H method. The software ADAMS is used to build a three-dimensional model and make a dynamic simulation. The Displacement, velocity and acceleration of the standard crank mechanism are gained. The dynamic simulation results show the Reasonableness of the standard crank mechanism and the Relationship between agencies of operation. Thus we can design standard crank mechanism flexibly to meet the needs of Synchronization control bidirectional stretching machine devices, and simplify the design of the device. Based on the kinematic analysis of the stretching chains, the kinematics model is established by Lagrange formulation. The virtual prototype model of bidirectional stretching machine is built by ADMAS and the motion conditions of chains are added. The theoretical values of Spatial Kinematics are calculated by reverse. The optimization model successfully predicts the reliability and stability of the stretching chains by compared with the empirical model and gets kinetic parameters of each stretching chain’s node. The research has important significance in designing chains and improving the quality of stretching machine.The kinematics analysis and simulation results show that through the computer simulation experiment, by reverse motion trajectory of the stretching chains, because the software operation’s exact and fast, the results obtained uniform tensile trajectory under ideal condition and can efficiently optimize the original equipment. After optimization the simultaneous biaxial stretching equipment has stretched uniform, the output of film has the physical stability of properties.