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- A new concept of automated manufacturing process for wire rope terminalsPublication . Figueiredo, D.; Silva, Francisco J. G; Campilho, R.D.S.G.; Silva, André; Pimentel, C.; Matias, J.C.O.The products related to automotive industry need to be extremely competitive. The metallic wire ropes used to open doors in the vehicles are based on a braided wire rope provided with accessories. The more expensive is the vehicle, the more complex is the required final wire rope. In order to prevent the corrosion and reduce noise, the internal metallic cable can be coated with a polymer via extrusion. However, this coating needs to be removed from the extremities of the metallic cable, allowing the zamak injection of the mechanical terminals, preventing die casting defects. Nevertheless, the standard machines able to produce the mechanical terminals by die casting process were always prepared to work only with non-coated metallic cable. Customers demanding coated metallic cables impose the need to adapt the standard machines to this new reality. Thus, new systems needed to be added to the standard machine, allowing the metallic cable strip operation. Moreover, this operation needs to be added to the process but without repercussions on the cycle time. Different approaches were studied and tested in order to find the best solution. The new device was designed and produced, allowing its test in real conditions. The system based on just one blade did not show satisfactory results, being necessary the use of a system based on multiple blades. The new device, when connected to the standard machine, allows to produce wire ropes up to 2.5 meters long, striped in both sides, letting the die casting injection of the zamak terminal in one extremity, with a cycle time of 7 seconds (1000 wire ropes per hour, as they are produced in couples).
- 3D finite element analysis and optimization of cap ply production system in the tire industryPublication . Silva, André; Silva, Francisco J. G.; Campilho, R.D.S.G.; Neves, Pedro M.P.F.In automotive industry, tires play a key role. They are a composite structure formed by multiple layers of different materials such as rubber compounds, steel and polyamide cords. Between the tread and steel belts, a cap ply layer is used to restrict the growth of the tire, due to centrifugal forces. Cap ply is produced by using a pultrusion process that impregnates polyamide cords with rubber, resulting in a rubberized strip. When the controlling of the process is incorrect, premature vulcanization or lack of impregnation is often observed. To optimize the production process, CFD (Computational Fluid Dynamics) simulations were performed to study the flow of rubber inside the extrusion head channels by modelling the fluid properties and the domain. Laboratory tests were also conducted to determine the physical and cure properties of the rubber compound used. Crossing the results of the simulations with the laboratory tests was found that the temperature control used was inadequate. Simulations were also supported with the results provided by a temperature sensor controlled by an external device (Arduino). By using a proportional integral derivative controller and changing the setpoints for the thermal resistance, the amount of scrap generated by vulcanized rubber and lack of rubber in the cap ply strips was reduced by 100%.