Full definition
Heat-resistant belts are specialized conveyor belts designed to withstand high temperatures while maintaining structural integrity and performance. These belts are critical in industries that handle hot materials such as cement, steel, and foundry products. The unique formulation of the rubber covers allows these belts to transport items like cement clinker, coke, foundry sand, sinter, hot slag, and asphalt without degrading. According to ISO 4195, these belts are categorized into temperature grades: T1 can resist temperatures up to 100°C continuously, T2 up to 125°C, T3 up to 150°C, and T4 can withstand up to 200°C. The DIN 22102 standard mirrors this classification, ensuring a level of consistency and reliability in belt manufacturing.
The compound formulations typically involve EPDM (ethylene propylene diene monomer) or SBR (styrene-butadiene rubber) blended with BR (butadiene rubber), enhanced with heat-stabilizing additives to improve their thermal resistance. The carcass of these belts is generally made from EP fabric, which is crucial for heat resistance. However, the bond between the plies is often the weakest link when exposed to elevated temperatures, which is why careful attention is needed during manufacturing and application.
Testing of heat-resistant belts involves accelerated aging at specified temperatures for 168 hours. This process evaluates changes in hardness, tensile strength, and elongation, which are critical indicators of the belt's performance under stress. The top cover thickness typically ranges from 4 to 8 mm, serving as a thermal insulator for the carcass. For applications involving temperatures exceeding 200°C, it is necessary to cool materials before they come into contact with the belt, or utilize special ceramic-fiber intermediate layers to protect the belt from thermal damage. These belts are essential in environments such as cement plants, steel mills, power plants, and foundries, where the risk of heat damage is significant.