Research subject: This research aims to revive outdated Kevlar fabrics for reuse in the manufacturing of polymer-based composite parts. As a polymer fiber with high tensile strength and significant resistance to impact and heat, Kevlar is used in various industries, including automotive, aerospace, and protective equipment manufacturing. This type of reinforcement alone does not give a good bond with polymer resins, and to create a strong bond, a conciliator (sizing agent) is used, which has a useful life. The physical and mechanical properties change over time due to environmental influences such as humidity, ultra-violet rays, and high temperature.
Research approach: In this research, among the thermal, mechanical, chemical, plasma, nanoparticles, and layering methods, the chemical method was chosen to revive outdated Kevlar fabrics. For this purpose, at first, three waste fabric samples were selected and finally, the tensile properties of regenerated and non-regenerated fabrics were compared according to the ASTM D638 standard tensile test.
Main results: The results showed that the chemically regenerated fabric had about 11.3% more tensile strength than non-regenerated fabrics, and the chemical regeneration process positively improved the mechanical properties of old Kevlar fibers. This achievement paves the way for the reutilization of aged fibers in advanced structures. This shows that the chemical regeneration process not only increases the mechanical strength of materials, but can also positively affect their durability and stability against environmental factors. In addition, this research provides an economic and ecological method for reviving old fibers, providing a basis for reducing industrial waste and reusing polymer materials.