摘要 |
An ultrasonic method for intermittently changing a condition of a workpiece is disclosed. The ultrasonic system includes an ultrasonic horn and a rotating anvil roll positioned to form a close relationship with each other comprising a nip. One of the ultrasonic horn and the rotating anvil roll includes an outer radial surface having a first length having a first amount of surface area per unit length of the respective outer radial surface, and a second length having a lesser amount of surface area per unit length of the respective outer radial surface. When ultrasonic energy is applied to the ultrasonic horn, the second length changes a condition of the workpiece when applied in the nip, but the first length does not change that condition. The change in condition occurs because the decrease in surface area along the second length increases the ultrasonic energy per unit area, as applied in the nip, to at least the threshold amount necessary to change the condition. Changes in condition of the workpiece include bonding together two or more layers of material, cutting one or more layers of material, or the like. Various patterns and designs can be provided at the working outer radial surface of the ultrasonic horn and/or the rotating anvil roll, for processing the workpiece. |