Moving web instability caused by the bending deflection of the support idle roller

The moving web is transported through a lot of rollers in the roll to roll process machines. These rollers are usually driven rollers, dancer rollers and idle rollers. The number of the idle roller is the largest in the roll to roll process machines. The kind of roller is a thin and long part. The bending deflection can be produced by the own gravity and the web tension. The influences on the deflection of the idle rollers by the web tension, gravity, shoulder length and wall thickness are analyzed. The investigation is focused on the dynamics of the idle roller and the web stability. The relationships between the roller dynamic and the speed and tension of the web are developed. The effect on the instability by the diameter of the idle roller, the length of the idle roller, the roller wall thickness, the surface properties of the roller and the web are discussed. The best parameter combinations of the web and roller are given. The results show that the guide rollers dynamic characteristics have a direct impact on the web motion stability