COST OF LAGGING FAILURE
Traditionally, many pulleys have been lagged with cold vulcanised bonding systems which were convenient to use and did not require the use of specialised equipment – effectively convenience was given priority over performance.
Today, the costs of conveyor downtime are enormous – for example, a conveyor transporting 12,000 tonnes/hour of ore, worth US$60.00/tonne, conveyor downtime costs the mining company US$720,000/hour.
For the past five years, Elastotec has collected data from our network of Approved Applicators on the modes of lagging failure that are seen on pulleys sent for refurbishment. Three of the most common modes of failure are:
- Debonding from the pulley shell.
- Edge lifting.
- Corrosion at the joints between lagging strips, leading to lagging debonding.
It has been well documented that cold vulcanised bonding of pulley lagging increases the likelihood of premature lagging failure due to debonding from the pulley shell, edge lifting, and corrosion of the shell at the joints between lagging strips. In many cases, these types of failures, require relagging on the conveyor, resulting in loss of production. Because the conditions for lagging on the conveyor are less than ideal, these problems often reoccur.