Monitoring creep and stress relaxation in splices on multiply textile rubber conveyor belts

The article discusses one of the most important issues related to a failure-free operation of belt conveyors, i.e. the problem of inspecting belt splices (Andrejiova, 2016; Zimroz et al., 2011), which are the weakest links in a belt loop operated on a conveyor (Jurdziak et al., 2016; Jurdziak, 2000). It presents the results of the investigation into the phenomena of creep and stress relaxation that occur in two different types of heat-vulcanised splices made on multiply textile rubber conveyor belts. The scope of investigation covered measuring the elongation of adhesive joints both in the connection points between individual splice steps and along the full length of the adhesive joint. The measurements of adhesive joint elongation included the allowance for creep and were performed directly after the load was applied to the splice. The findings suggest that although splice deformation is significant, the changes in the stresses that occur in the adhesive joint remain insignificant due to stress relaxation. In practice, a several-hour waiting time should be assumed before measurements can be taken. During operation, splices on multiply textile rubber conveyor belts undergo significant deformation due to material creep. Therefore, most information is provided by investigating splices of standard, full length. This paper presents the results of tests that take this phenomenon into consideration. Such tests have never been performed before, and their results constitute important information for the producers and users of conveyor belts. They allow an optimal choice of adhesive compositions used in splicing multiply textile belts and also they indicate directions for further research.