Understanding the Role of Abrasion Resistance in Belt Sealing Systems
It is a common misconception that the sealing system must be "softer" than the belt cover to ensure the seal wears before the belt. However, a wide range of materials can be appropriate for edge seals. The key factor to consider is not whether the material is harder or softer than the top cover, but whether it has a lower abrasion resistance than the belt. Abrasion resistance is not measured by a durometer, which rates hardness, but by an abrasion index, such as Pico, Deutsches Institut für Normung (DIN), or Taber ratings.
Often, belts will develop signs of wear at a fixed distance from their edge that appear to be caused by overly abrasive or poorly adjusted belt seals. Generally, this wear is the result of fines or other materials trapped underneath the seal. This entrapped material is most often seen on belts without proper belt support or on conveyors where material loading begins while the belt is in transition, as the changes in belt shape make it easy for material to be trapped under the skirtboard.
It is also important to examine other nearby chutes and conveyors for leakage or spillage that could fall onto the belt.