Influence of Saw Blade Tension on the Stability of Sawing Processes

Sawing with bandsaws is a fast and efficient process for cutting semi-finished parts out of bar stock in the metalworking industry. However, the produced surface quality on the workpiece is low due to the unguided length of the saw blade during the engagement in the workpiece. The kinematic correlation between the thin, unstable structure of the saw blade, only pre-stressed in the cutting direction, and the distance of the two saw blade guides according to the workpiece dimensions leads to an indefinite behaviour of the saw blade in the kerf. Apart from the surface quality, this cutting behaviour also causes a great wear of the tool. With increasing wear of the tool, the process becomes more and more unstable and the cutting loss increases. For an optimization of the sawing process, the influences on the stability of the process are investigated by experiment on a test bandsaw equipped with extensive measurement equipment. This paper examines how the saw blade tension influences the stability of sawing processes subject to tool wear. For this purpose, the saw blade tension is varied in a wide range and the stability of the process is assessed. The results obtained show a great influence of the saw blade tension on the sawing process and form the basis for developing a stand-alone stability control system to automatically adjust the sawing parameters.