Shrinkage properties of wool treated with low temperature plasma and chitosan biopolymer

Low temperature plasma treatments of wool modify only the cuticle surface of the fibers, improving their surface wettability, dyeability, fiber cohesion, and shrink resistance. The shrink-resist properties obtained with plasma treatment do not impart a machine-washable finish, which is an important end-user demand. However, the shrink resistance of air plasma treated wool is suitably enhanced by a subsequent biopolymer chitosan application. Using a qualitative colorimetric method, chitosan adsorption is shown to increase after treatment with air plasma. SEM observations yield information about the etching effect and chitosan adsorption. Given that both kinds of treatments, air plasma and chitosan, are environmentally acceptable, a new ecological shrink-proofing process is proposed.