Dear Venkatagopal,

It is not a question of indention degree, which could be called strain, but of the combination of indention and recovery efficiency of the rubber once deformed. A perfect rubber, which would exhibit no rolling loss, is one with perfect recovery of the deformation that has no time lag during recovery.

Many articles have been published on the concept back into the 1960's. Spaan made a major rubber technology contribution in 1978:

1. Spaan, C. Two Dissertations in 1978 on idler roll indention, belt flexure, and rolling losses of idlers. This and many other authors (7-8) are referenced in my first rolling resistance publication in Bulk Solids Handling (BSH) in Vol. 11 No. 4 November 1991 entitled:

Nordell, L.K, "The Channar 20 km Overland A Flagship of Modern Belt Conveyor Technology"

2. Jonkers, C. "The Indention Rolling Resistance of Belt Conveyors, Forden und Heben, Vol 30 1980. Jonkers was a student of Spaan prior to his appointment at Twente Univ. in the Netherlands.

2. Hager, M & Hintz, A., "Energy Saving Design of Belts for Long Conveyor Systems", BSH, Vol. 13, November, 1993

3. Nordell, L.K., "The Power of Rubber – Part I", BSH, Vol. 16, July, 1996

4. Nordell, L.K., “Zisco Installs World’s Longest Troughed Belt, 15.6km Horizontally Curved Overland Conveyor”, BELTCON 8, October 1997.

5. Nordell, L.K., "Improving Belt Conveyor Efficiencies: Power, Strength, & Life

W/ overland system case studies" IIR conference April 1998. More references on other authors are tabulated.

5. Nordell, L.K., "Overland Conveyor Design for Efficient Cost & Performance”, presented at IIR conference in Australia. 1998? ■