Shaping the parameters of cylindrical belt surface in the joint area

Most of the industrial machines use round-shaped drive belts for power transfer. They are often a few millimetres in diameter, and made of thermoplastic elastomer, especially polyurethane. Their production process requires the bonding step, which is often performed by butt welding, using the hot plate method. The authors have undertaken to design an automatic welding machine for this purpose. Consequently, it is required to carry out a process analysis of hot plate welding, which entails describing the dependency between technological parameters (temperature, pressure force, time) and the quality of the joint, especially the outer surface of the belt around the weld. To analyse this process in a proper way, it is necessary to describe the physical phenomena that occur in the material, during particular operations of the hot plate welding process. One of the most troublesome phenomena occurring during the welding process is removing of the flash. These round rings, placed around the weld, which remains after the joining process, are unacceptable in the finished component. The authors took an effort to design the necessary equipment for removing of the flash after welding, using some simple parts that cut off excessive material. The paper shows the three possible solutions for flash removal. They were verified experimentally, and afterwards, the best solution was chosen. Additionally, a number of analytical calculations were carried out in order to determine the maximum force value required for this operation. Results of the analytical calculations were compared with experimental results.