1. The thickness of the ring die is too thin and the strength decreases 2. The ring die is forcibly squeezed in by hard objects during operation (such as metal objects such as bearing balls falling in the granulating chamber) 3. The gap adjustment of the roll die is too small 4. The clamping surface of the ring die is severely worn, and the clamp ring is not tightly clamped or the clamp ring falls to the bottom will cause the flange to be damaged.