Mr. Jochman

Conveyor Dynamics, Inc. (USA) would be pleased to collaborate. We also are studying wear properties on all forms of conveyors.

We find the major properties of wear are:

1. Shear work index - rock sliding and pressure magnitude over width and axial pattern in the loading zone. . If the observed damage is all abrasion, then shear work has a linear correlation to belt life.

2. Impact force at rock tip contact with belt - when the value exceeds the rubber tensile value the ruber cracks to relieve the stress. If the observation is gouging related, then the damage is logrithmic. The combined abrasion and gouging damage is difficult to quantify unless you have means to separate the observed behavior, such as Discrete Element Modeling (DEM).

See our publications on these topics at our website:

www.conveyor-dynamics.com

3. Rock shape and sharpness of its edges - cutting index like gouging, this property is dependent on the impact force at the rock edge or tip that can cut or slice the rubber

4. Shear and impact are related to rock properties ( size, sharpness of edges and density), flow rate, and chute design ( directly producing the magnitude of shear work and impact magnitude (velocity and kinetic energy vector)) Changes in chute design (geomerty and surface treatment) can reduce the shear, impact, and cutting physical magnitudes by many times. This directly correlates with belt life.

5. Rubber properties that register abrsasion, gouging, and cutting indices. Cross link density and viscoelastic properties are major indices that correlate with resistance to damage.

Hoping to hear from you,

Lawrence Nordell

President

Conveyor Dynamics, Inc.

1111 West Holly st.

Bellingham, WA 98225

USA

ph 360/671-2200

fx 360/671-8450

email: nordell@conveyor-dynamics.com ■