Maximizing the Lifespan of Your Conveyor Belts
Material handling operations come to a halt when a conveyor belt needs replacing. Even when scheduled, that’s expensive, but if the replacement was unplanned costs rise dramatically.
The way to minimize this cost and disruption is to maximize conveyor belt lifespan. Taking good care of belts starts with how the system is designed and extends into day-to-day inspection and maintenance. Here’s some advice on making belts last longer.
TYPICAL CONVEYOR BELT LIFESPAN
Most belts last at least three years. If they need replacing more frequently either there’s something wrong with how the system was designed, there are serious issues with the system, or the belt is wrong for the application. Some users can get 10 years of service from their conveyor belts, which shows that longer life is possible. However, this depends on how intensively the belt is used.
HOW HARD IS THE BELT WORKING?
The largest factor in conveyor belt lifespan is its length. This is because most wear occurs at the loading point when material falls onto the belt. Once the belt has accelerated the material to the forward velocity of the belt, there’s no relative motion, so no wear.
On a short run, any given spot on the belt will experience the impact of loading more frequently than if the conveyor is much longer. Thus it’s fair to say that longer belts will almost certainly last longer, (providing there are no alignment or other issues.)
OTHER DESIGN ISSUES & BELT LIFE
The most important point to consider is how material gets onto the belt. Lower impact forces will extend belt life. A well-designed transfer chute or loading zone drops material gently onto the center. The best systems give the material some forward velocity as this reduces belt loading. Screens or bars in the chute will prevent over-large pieces from landing on the belt.
Drive pulley diameter is another important factor. A smaller diameter pulley deforms the belt more, which can accelerate cracking. Always use a drive pulley of a diameter appropriate to the belt material and thickness.
Dust is a major issue in many mineral or aggregate transport applications. This gets into bearings where it increases resistance and drag on the belt. While it’s impossible to avoid dust, a good dust containment system will greatly reduce its impact.
An obvious, though sometimes overlooked, point is belt strength. Strength is specified in pounds-inch width or PIW. Underestimating the PIW rating needed is a common reason for premature belt failure. Calculators are available for working out the PIW required in a belt, or just follow the recommendations of your belt supplier.
MAINTENANCE FOR MAXIMIZING CONVEYOR BELT LIFESPAN
In addition to the design issues, there are several issues to watch for in day-to-day belt operation. A daily inspection is recommended to look for:
- Mistracking
- Material carryback
- Belt slippage
- Belt damage
Mistracking is where the belt runs to one side of the supporting structure. This causes the belt to rub and wear while also increasing loads. Mistracking can have several causes. If seen during the regular inspection it should be corrected immediately.
Carryback is where material stays attached to the belt rather than dropping into a transfer chute at the end of the belt. This increases loads on the belt and impacts with idlers will shorten their life.
Carryback is reduced by using well-adjusted scrapers. These need periodic maintenance to attend to points such as cleanliness, position, and tension.
Once a belt starts to slip the drive surface becomes polished and it becomes much harder to apply the required load. The motor will work harder while the belt stretches and eventually breaks. Drive pulley lagging, which provides the friction that moves the belt, is a primary cause of slip. Lagging wears over time, (3-5 years is the typical life,) and eventually leads to slippage. Ceramic lagging lasts twice as long.
A conveyor belt can be damaged by material or foreign objects falling on it or getting wedged against the belt. Once a cut or tear has started it will almost certainly grow until the belt fails. A daily inspection should be enough to detect such a problem and allow scheduling of repair or replacement before belt failure becomes imminent.
PREVENTING BREAKDOWNS & SAVING MONEY
For many industries, underground conveyor belts or surface/overland conveyor belts are essential for cost-effective operations, but they’re also a point of vulnerability. If the belt stops, alternative ways of moving material are slow, inefficient, expensive, and potentially dangerous.
Taking care of conveyor belts maximizes their lifespan and reduces the risk of breakdowns and unplanned stoppages. That means substantial efficiency gains and cost savings.
Learn more about maintaining your conveyor belt.