Carpet treatments, chemicals

Polyamide-6 (Nylon-6, Perlon) and polyamide-6.6 (Nylon-6.6) are the most well known polyamides. Polyamide-based filaments find wide spread applications as yarns for textile or industrial and carpet materials [70], However, nylon-based textiles are uncomfortable to wear and difficult to finish due to their hydrophobic character. This characteristic also leads to fouling of PA-based ultrafiltration membranes by proteins and other biomolecules which increases the energy demand for filtration and requires cleaning with aggressive chemicals or replacement [71-73], Consequently the enhancement of the hydrophilicity of nylon is a key requirement for many applications and can be achieved by using plasma treatment [74-76], As a promising alternative, enzymatic hydrophilization of PA requires less energy and is not restricted to planar surfaces. 

Foam technology is used to apply stain release chemicals to carpet. Liquid solutions normally used for treatment are replaced with foams. Wet pickup is lowered to as little as 8% in special applications, compared to 100% wet pickup in conventional methods [72]. The minimum pickup level for good finish penetration on cotton and cotton blends is about 45% [71], The reduction in water use at one plant was 20 million liters per year, and energy was cut 10% overall [72], However, foam and the surfactants necessary to produce it have their own set of problems in wastewater. 

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