ANALYSIS OF TENSILE PROPERTIES OF WORN FABRIC CONVEYOR BELTS WITH RENOVATED COVER AND WITH THE DIFFERENT CARCASS TYPE

Conveyors are the means of transportation used in many industries. The load-bearing and tractive component of a belt conveyor is a conveyor belt which consists of a carcass and cover layers. During an operation, belts are exposed to loads that cause damage to the belts. It is therefore necessary to ensure that a conveyor belt possesses required mechanical properties during the transport of material. The key mechanical properties of a conveyor belt are tensile properties. They are significantly affected by the fabric carcass of a conveyor belt. The tensile properties of conveyor belts are largely affected by the carcass materials. They are also affected by the types of fibres in the longitudinal (warp) and transverse (weft) directions of the fabric carcass because the carcass transfers all tensile stresses of the conveyor belt. A fabric conveyor belt is regarded as a composite material, consisting of the carcass (polyamide P and polyamide-polyester EP) and the cover layers. The costs of a conveyor belt represent 10-30 % of the price of the entire conveyor. It is therefore reasonable to prefer only those conveyor belts that show the properties prescribed by relevant norms. The subject of the article is worn conveyor belts with renovated top cover (renovated conveyor belts). The tensile properties are used to assess the suitability for further use of renovated conveyor belts in practice. The article presents the analysis of tensile properties of renovated fabric conveyor belts in relation to the carcass type. The observed results were compared applying the DOE method, regression and correlation analysis, and the method of statistic induction. All the conclusions, made based on the above-listed methods, are identical for the examined tensile properties. The results indicate that the examined tensile properties of conveyor belts have not undergone any significant change after the renovation of the top cover layer.