At a tire builder, freshly manufactured rubber material, is spooled on rolls at the end of the production machine. The rolls rotate slowly and take up the material.
If the rolls are full, they are rotated so the ends are on top, so that they can be removed by a forklift. Afterwards a new roll can be placed there again. For the start-up of a new roll, spooling slowly yet controlled is necessary, worker interaction must be possible.
On one hand, the material is not produced at a constant rate, but the rolls rotate at a constant speed. On the other hand, during change of roll, material is still produced. To separate this process, in between loops are used as a continuous production buffer. This is more commonly called loop control.
The hazard for the workers is that they can become caught up in a roll and trapped. The hazardous rotating movement can hurt a worker and therefore access must be protected.
The monitoring of the area underneath the rolls is done by safety laserscanners, area light curtains or sometimes by safety mats (e.g. textile material: some fabric fibers fall to the ground. This situation shouldn’t be result in a shut down. Due to the light weight of the fabric they won’t activate the mat). The worker would activate the mat directly if he entered this area. In this case rolls stop. Afterwards a manual restart is required from outside this area to restart winding. The removal area in which the forklift accepts the rolls is protected by 2 S3000 safety laser scanners, or light curtains which make sure that no worker is inside when the full rolls are removed. After tilting and removing the roll a new roll must be set-up. For start-up safe limited speed is required, activated by enabling switch. After start-up, a manual reset is required even if the laser scanners or curtains have stopped the machine.
Additionally there are emergency stop push-buttons that stops the roll actuators manually. These and all other safety components are connected to the Flexi-Soft safety controller.