Simulation on Skew and Folded Wrinkle of Film Transferred by Misaligned Roller

Abstract

Various kinds of films and tapes are produced and widely used in many industrial fields. In order to raise productivity, both speed-up of line velocity and widening film width are highly requested. However, many technical problems occur in film production lines. The problems are skew, wrinkles, winding distortions, and so on. In this study, motion and deformation of a film which is transferred by four rollers including a misaligned roller are simulated by FEM software, in order to clarify characteristics of film skew and wrinkle occurence and effects of main parameters on these characteristics. The simulation results show that the film skews to the direction in which the roller distance decreases and the film approaches a certain position, when the movement of film width direction is constrained. While, it continues to skew to the opposite direction when the constraint is removed. The skew becomes larger as the width, thickness, Young's modulus of the film or the misaligned roller angle increases or as the roller diameter or roller distance decreases. A wavy wrinkle (trough) of the film due to misaligned roller runs on to the roller, and the width of the wrinkle becomes smaller because of the difference of the skew velocities of the two film areas separated by the wrinkle on the roller, and finally it becomes a folded wrinkle. Decreasing the friction force suppresses the folded wrinkles.