Rotary cutting as an alternative method in the processing of electrical steel strip: Geometric and kinematic determination of the process setup

Improving the efficiency in production is always the aim. In many applications, where progressive stamping approaches the technological limits, rotary cutting is successful. Relevant applications to name are the processing of paper, card boxes, packaging and simple perforated steel profiles. The main limiting factors of the stamping technology are the accelerations and decelerations in sheet feed and stamping motion. In contrast rotary cutting is a continuous process which leads to greater speeds and higher output. While performing the electrical steel strip between two cylindrical tools in stamp and die arrangement, the laminations are being cut out. Rotary cutting in the manufacture of laminations is a great challenge and a research topic at the Bavarian Technology Center for Electric Drives at the FAU. This paper provides the main technological differences between progressive stamping and rotary cutting regarding the process structure. Furthermore the geometric and technical parameters of the rotary cutting process are described mathematically. Finally the correlation of process parameters are identified.