Studies on needle-punched natural and polypropylene fiber nonwovens as oil sorbents

This article reports on oil sorption behavior of needle-punched nonwoven fabrics made from milkweed, kapok, cotton and polypropylene fibers using air-lay and carding technologies. The effects of fiber and fabric parameters on oil sorption and retention capacities, and oil sorption rate and fabric strength were investigated. Fabrics made using natural fibers such as milkweed and cotton were found to selectively absorb oil over water. Milkweed and kapok nonwovens displayed higher oil sorption and retention capacities as compared to cotton and polypropylene nonwovens. Further, milkweed and kapok nonwovens exhibited higher oil sorption rate as compared to cotton and polypropylene nonwovens. The porosity of nonwoven fabric was found to play a vital role in determining the oil sorption capacity. Although the web-forming technology did not affect the oil sorption and retention capacities and oil sorption rate, it affected the fabric strength significantly. Cotton nonwoven kept on artificial sea water for 10 days displayed very low water sorption capacity, although the nonwovens produced using natural fibers exhibited preferential sorption of oil over water and high oil sorption and retention capacities; which are advantageous in using them as oil sorbents to cleanup oil spills on oceans, but they offered low fabric strength. These findings indicate that further research works are required to improve the strength of natural fiber nonwovens for sustainable oil spill removal.