Development of alkali-treated surface-modified coir fibre filter for 1µm to 10 µm particle filtration and process optimization

Filtration of Particulate Matter (PM) 2.5 and PM 10 particles are focused by the filters used in Heating, Ventilation and Air Conditioning (HVAC) systems. Synthetic fibres/filaments are widely used to construct the filters for air conditioning filters and cleanroom filters which is not biodegradable. Natural fibres are easily biodegradable, exhibit better filtration characteristics as like synthetic fibres. In this research, alkali-treated coir fibres are used to construct the filter for filtering the particle range of 1.0 µm to 10 µm. Box- Behnken experimental design was used for the experimental plan and the experiments were conducted to construct the filters. The change in fibre properties by alkali-treatment was observed and the treatment with 5% and 10% alkali increases the crystallinity index of fibres. The influence of independent variables on the performance of developed filters was analyzed in detail. 5% NaOH treated fibre sample with 20% resin proportion and 60 g fibre content in the unit area was identified by a quality factor as the best combination of independent variables for constructing filter.