For many decades lagging has been used to both protect conveyor pulleys and to increase the available friction for driving the conveyor belt. Today lagging is available in various embodiments with differing stated capabilities and strengths.
A primary consideration in the choice of lagging is the coefficient of friction. Designers use the friction coefficient in the Euler Capstan equation to calculate the drive capacity of the conveyor, so the behavior of lagging friction under real world conditions is of extreme interest. As belt technology innovates with increasing tensions and more power delivered through the drive pulleys, a correct understanding of the source of friction is necessary.
This paper will review a technique for measuring lagging friction coefficients under typical conveyor belt pressures (35-700 kPa) and discuss the surprising results. It will then explore the concept of lagging traction as a more accurate depiction of drive capacity.