Abstract
A diagnostics of conveyor belt rubber layers consists a significant part of non-destructive diagnostics in conveyor belt transportation. Used rubbers undergo during their operation an aging process caused by the aggressive character of external environment and therefore their life-time decreases.
The main changes of physical properties appear firstly on their surface being in an immediate contact with the cargo transported and/or with an ambient air. Changes of CB structure caused by the aging are reflected mainly in changes of network density and glass transition temperature Tg.
The monitoring of mentioned changes we have done by dielectric relaxation spectroscopy. The real and imaginary part of complex permitivity ε* was measured by interdigital dielectrometry which is based on plane layout interdigital electrodes.
The change of geometry involves the spatial distribution of electric potential between electrodes and so the depth p of electric field into measured material. The depth p equals to p=(D+L)/π, where D denotes the interval between electrodes and L their width.
Experimental results obtained by this method are compared with mechanical and hardness measurements.