Impact roller, also known as an impact idler or buffer roller, is a type of conveyor roller used in conveyor systems to absorb and reduce the impact force generated when materials are dropped onto the conveyor belt. These rollers are designed to minimize the damage to both the conveyor belt and the conveyed materials by providing a cushioning effect.

Key features and functions of impact rollers include:
- Impact Absorption: Impact rollers are specifically designed to absorb and dampen the shock and impact forces that occur when heavy or bulk materials are dropped onto the conveyor belt. This helps prevent damage to the conveyor belt and minimizes spillage.
- Construction: Impact rollers typically have a reinforced structure with a rubber or polyurethane coating on the roller surface. This coating acts as a buffer to cushion the impact and protect the belt and materials.
- Reduced Material Spillage: By absorbing the impact force, impact rollers help reduce material spillage and dust generation, improving the overall cleanliness of the conveyor system.
- Extended Belt Life: The use of impact rollers can significantly extend the life of the conveyor belt by reducing the wear and tear caused by frequent impacts.
- Load Support: In addition to absorbing impacts, impact rollers also provide the necessary support for the conveyor belt and the conveyed load. They help distribute the load evenly across the width of the belt.
- Various Configurations: Impact rollers come in different configurations, including troughing impact rollers (for carrying the material) and flat impact rollers (for impact zones with low material heights). They can also be used in combination with standard carrying rollers.
- Maintenance: While impact rollers are designed to absorb impacts and reduce wear, they may require occasional maintenance to replace the rubber or polyurethane coating if it becomes worn or damaged.

Impact rollers are commonly used in industries such as mining, quarrying, construction, and bulk material handling, where heavy materials are loaded onto conveyor systems. They are strategically placed in impact zones, such as loading points and transfer points, to protect the conveyor equipment and minimize the risk of damage or downtime due to high-impact loads.