Influence of fibre properties and its proportion on filtration behaviour of thermo-bonded multilayer nonwoven

Purpose The purpose of this paper is to study the influence of fibre properties on filtration behavior. Air pollution is a major threat to human beings due to industrialization and urbanization. Among various particles in the atmospheric air, PM 2.5 causes various respiratory problems to human beings and also causes premature engine wear. The primary importance for the filters is higher filtration efficiency with lower pressure drop. Design/methodology/approach In this research, nonwoven filters were developed with different diameters of polyester fibres such as 0.8d, 1.2d and 6d fibres and different proportions of fibres were used. The Kuwabara cell model was used to derive certain parameters and its effects were analysed. The effect of basis length, solid volume fraction and porosity on filtration behavior was discussed in detail. Findings The filtration efficiency is higher for particle size from 1–3 µm, when different layers of polyester fibres are used with coarser fibres as the top layer and finer as the bottom layer. The filtration performance is better for layered nonwoven than unimodal nonwoven. The higher proportion of micro-denier fibres results in higher filtration efficiency with higher pressure drop. Research limitations/implications The proposed research is more suitable for the particle size of more than 1 µm because of the fibre diameters and its achievable porosity. The filtration efficiency can be increased further by increasing the mass per unit area, which also increases the pressure and is not recommended. Originality/value The effect of triple-layers with different diameters of fibres on filtration was analysed. Due to the variation in diameters of fibres in different layers, the filtration performance varies.