Development of bimodal nanofibrous filter media via hybrid spinning of recycled PA6 and acrylic for oily aerosol filtration

Oily aerosols are a major contributor to air pollution, pose serious health risks, and can lead to corrosion in industrial systems. As a result, oil-free air is a critical requirement in various industrial settings. However, the removal of oily aerosols from air remains a complex and costly challenge. Filtration using fibrous filter media is a conventional method for capturing aerosolized oily aerosols, yet achieving both high filtration efficiency and low pressure drop for submicron-sized oily aerosols remains a key research focus. Additionally, the single-use nature and synthetic composition of most fibrous filters raise environmental concerns. In this study, high-performance oily aerosol filters were developed using hybrid nanofibrous structures fabricated from recycled PA6 and acrylic fibers through an innovative nanofiber production method. A novel thermal bonding process was applied to enhance the mechanical strength of the mats. The recycled PA6 and acrylic nanofibers exhibited average diameters of 98 nm and 560 nm, respectively. The modified filters demonstrated a contact angle of 110° against paraffin oil and achieved filtration efficiencies exceeding 90 %. Thermal treatment at 200 °C resulted in a 60.92 % increase in tensile strength for the HM samples. This approach offers a sustainable and efficient solution for oily aerosol filtration.