Industrial ecology in Morocco: wet laying composite air filter membrane based on cottonized sisal fibers and recycled nonwoven supermarket bag

Our study is part of the context of the waste valorization and aims to develop a nonwoven composite membrane based on cellulosic fibers extracted from the sisal and the nonwoven bag recycled by shredding. This study offers significant advantages in terms of cost, durability, filtration performance, and physicochemical properties. Divided into three phases, the study involved the pretreatment of sisal fibers with chemical agents. The second step consisted of the manufacture of the membrane, and the last step concerned analysis and the evaluation of the degumming rate. Thus, analyses such as infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), optical microscopy (OM), X-ray diffraction (XRD), and laboratory tests (pH, air humidity absorption, flammability) were carried out. Filtration performance, including differential pressure or pressure drop (ΔP), particle filtration efficiency (PFE), and quality factor (Q), were also measured and compared to some air filtration membranes reported in the literature. The results showed good chemical treatment efficiency of the fibers, their reduction in diameter to the micrometric order, and their compliance with pH standards. The treated fibers also showed improved thermal stability, a type I_β crystal structure, and good flame resistance. The composite membrane achieved a particular filtration efficiency of 99%, a pressure drops of 127.514 Pa and 3.66 Pa⁻¹ as quality factor. These filtration performances have proven to be better with good filtration quality, compared to certain commercial membranes reported in the literature used in the automotive fields and as anti-dust protective masks.