Annular rings

1. Generally caused by slitter run-out if they appear in a regular pattern and are about 0.15 mm in depth.

— run-out is deviation of slitter from vertical plane.

2. In shear-cut slitting, the rings are uniformly spaced apart by an amount nearly equal to the diameter of the bottom slitter.

3. For score-cut slitters, the rings are regularly spaced apart in an amount equal to the diameter of the slitter.

— remedy is to grind the slitters correctly.

4. An irregular pattern of annular rings is probably due to wobbly slitters.

— check and ensure proper fit of bottom slitters to shaft and change bearings in the top slitters.

5. For individually mounted bottom slitters, check the bearings and make certain the slitters are properly ground.