Research On The Key Problems Of Variable-magnification Static Film Bidirectional Synchronous Tensile Equipment

The principle of the biaxial stretching of plastic film is that the extruder heats and fuses the polymer material into a thick film,and then stretches the polymer chain or crystal surface at a temperature higher than the glass transition temperature and lower than the melting point to make the molecular chain or crystal.The faces are arranged in an order parallel to the plane of the film.Magnification Biaxial stretching is a mainstream plastic film forming method in recent years.This method uses a bidirectional synchronous stretching structure to significantly improve the barrier properties,mechanical properties,thermal properties,and optical properties of the film,and makes the film thickness more uniform,satisfying Application requirements in various production areas.This article describes the kinematics and dynamics involved in stretcher design.The theory of kinematics analyzes the transformation of the global coordinate system and the local coordinate system,and the transformation matrix is ??obtained.The method of solving any instantaneous angular acceleration,angular velocity and angular displacement is obtained.Based on the analysis of the principle of synchronous biaxial stretching,a synchronous stretching model was established,and the relationship between various points was obtained.A new type of film clamping mechanism has been designed and developed.This mechanism realizes the film clamping function in the synchronous two-way stretching process,and is characterized by high reliability and simple operation control.When the film holder is fully closed,the offset angle of the gripper is designed to be 11 o,which can cause the gripping mechanism to produce self-locking during the gripping of the film and prevent the film from being clipped to produce waste products.The finite element analysis theory was used to analyze the reliability of the screw and the fixed frame in the key components.The analysis results showed that the precision of the screw and the fixed frame meet the requirements.The two-way synchronous motion of the stretching machine was simulated and there was no interference during the movement.The temperature distribution of the chamber was analyzed on the stretching case,and the temperature field in the cavity could meet the requirement of film stretching.This article has completed the overall design of the film biaxial stretching machine.The biaxial stretching machine is mainly designed from a stretching system,a heating device,a hot air system,an electrical and a control system,and a film synchronous stretching function is realized.