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EN
The paper discusses the topic of butt welding of polyurethane drive belts by the hot plate method in the context of modeling the process of this technological operation. Based on the analysis of the butt welding process, a series of studies of the thermomechanical properties of the material from which the belt is made has been planned. The results will be used for mathematical modeling of the welding process, and in particular its most important phase: the plasticizing operation. On this basis, the study of the compression of cylindrical specimens taken from the belt has been performed at two different speeds. Their result is the relationship between the compressive stress σc and the modulus of longitudinal elasticity Ec at compression and: deformation εc, temperature value T, as well as the compressive velocity vc. In the next step, dynamic viscosity η of the belt material was determined based on the results of dynamic thermomechanical analysis. The research work culminated in the attempts to plasticize the material on a hot plate, in conditions similar to the process of industrial welding. These studies were performed at different speeds vpl, resulting in the correlation between the force required for plasticizing Fpl and the value of the speed of the belt end vpl relative to the hot plate heated to a temperature Tp. The obtained results will be used to formulate a mathematical model of plasticizing the material, based on the selected mechanical deformation models.
EN
Belt conveyors are commonly employed in manufacturing and excavation processes. One of the basic components of such equipment are flat transport belts which can be monolithic or composite. In both cases, the belts are most often made of plastic materials. The manufacturing process of flat transport belts usually involves two stages. During the first stage, belts of very high length of up to several hundred meters are manufactured with use of the correct technology for a given belt type. In order to be usable in the finished conveyor system, correct length of such belts is to be achieved. Considering the above, the subsequent stage of manufacturing requires cutting the belts down to the appropriate length and very often joining the ends to form a closed loop with specific circumference. In an attempt to answer the demand of the manufacturing industry, the authors took up design works on an automated device for crosswise cutting of monolithic and composite belts. This article presents three construc-tion concepts of the authors’ own design together with an analysis of construction and operating factors which affect their usability. The presented discussion leads to selecting one of the solutions for which a drive system concept designed by the authors is proposed. Additionally, an analysis of the influence of the cutting knife geometry on cutting force is provided.
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