Antimicrobial and blood repellent finishes for cotton and nonwoven fabrics based on chitosan and fluoropolymers

In order to impart barrier properties against microorganisms and blood to 100% cotton fabrics and 55/45% woodpulp/polyester spunlaced nonwoven fabrics, samples are treated with chitosan and fluoropolymers using the pad-dry-cure and pad-cure methods, respectively. Antimicrobial activity of the samples is analyzed quantitatively by measuring the number of colonies of Staphylococcus aureus. Blood repellency is assessed with an impact penetration test using synthetic blood. Laundering durability of the finishes is measured, and scanning electron microscopy is used to evaluate changes in the fabric surfaces. To investigate the effect of finishing on the hand and air permeability of fabrics, the mechanical properties of the samples are measured by the KES-FB system. Samples treated only with chitosan show a high reduction rate in the number of colonies. Dual finished specimens treated with 1.1% chitosan concentration also maintain over 90% reductions in the number of colonies. The blood repellency of dual finished nonwoven fabrics is superior to that of dual finished cotton. Dual finished cotton fabrics exhibited durable antimicrobial activity with repeated laundering. As regards mechanical properties, bending rigidity and shear rigidity increase when cotton and nonwoven fabrics are treated only with chitosan, but these properties decrease after the fluoropolymer treatment. Air permeability of the specimens decreases slightly after the dual finish.