Which factor most rapidly degrades belt life in PMMI mechanical drives?

• A. Excessive heat.
• B. Proper lubrication.
• C. Correct tension.
• D. Adequate cooling.

Answer: (A)

Excessive heat rapidly shortens belt life because heat directly ages and weakens the belt material. Belts are designed to run within a specific temperature range; when they overheat, the rubber compounds oxidize, harden, and become brittle, while the fabric/Cord reinforcements can lose strength. Heat also causes the belt to glaze or crack, reduces elasticity, and accelerates wear from friction, leading to faster cracking, chunking, and eventual failure. All the other factors help protect belt life—proper lubrication reduces bearing friction, correct tension prevents slippage and over-stretching, and adequate cooling helps keep the belt within its safe temperature range. But when heat becomes excessive, it accelerates deterioration far more quickly than those other factors can counteract.