Effect of aramid reinforcement on mechanical properties and aging resistance in EPDM rubber hoses

In this thesis study, aramid-reinforced EPDM (ethylene propylene diene monomer) rubber, one of the synthetic rubber types widely used in the automotive industry, was comprehensively investigated. Owing to its superior heat, ozone, aging, and chemical resistance, EPDM is preferred in harsh operating conditions such as the engine compartment, where high temperature, vibration, and pressure are present. The aramid reinforcement structure, on the other hand, is employed to enhance the mechanical strength, flexibility, buckling resistance, and dimensional stability of the hoses. During the production process, carbon black, fillers, vulcanization agents, accelerators, antioxidants, and processing aids were mixed in specific proportions to prepare rubber compounds, followed by vulcanization in an autoclave. Hoses were manufactured using different aramid yarn thicknesses (930, 1100, and 1680 dtex) and pitch distances (2.9 mm, 3.3 mm, and 4.0 mm), and the influence of these parameters on hose performance was systematically evaluated. Within the scope of the experimental studies, the morphological properties of the produced hoses were examined using SEM (Scanning Electron Microscopy), while their mechanical behaviors were investigated through adhesion, burst pressure, diameter expansion, tensile, hardness, and elongation tests. The results revealed that the aramid reinforcement ratio and braiding parameters have a significant effect on the pressure resistance, deformation behavior, elasticity, fatigue strength, and layer adhesion performance of the hoses. In conclusion, this study provides a comprehensive evaluation of the structural, morphological, and mechanical performance of EPDM-based aramid-reinforced hoses and offers valuable insights into material selection, production conditions, and reinforcement optimization, contributing to both academic research and industrial applications in the automotive field.