Plasma technology is currently implemented in a wide range of industrial processes due to high efficiency, low environmental impact and simplicity. Low-temperature plasma treatment can be an alternative to traditional wet processes in textile preparation and finishing, causing modification of the fibre surface, which is mainly responsible for the material end-use properties i.e. wettability, dyeability, printability, shrinking, pilling etc. Appropriate choice of gas and control of plasma operation conditions provide a variety of effects on textiles (improvement of dyeability, printability and colour fastness, improvement of adhesion properties of coated fabrics, increase in hydrophobicity and water resistance, etc.). However, in spite of extraordinary efficiency, multifunctionality and simplicity, low-temperature plasma treatments still cannot replace all wet finishing processes, though they can be viable pretreatments that offer plenty of environmental and economical benefits.

The aim of this study was to investigate how morphology of fibers is affected by plasma during the process of decolorization by a low-pressure RF plasma (gas, treatment time, and power were varied) and atmospheric pressure industrial corona (number of passages and power). CIE LAB colorimetric system was used for determination of color difference between untreated and differently plasma-treated denim fabrics. Particular emphasis was put on the morphological changes induced by plasma treatment, because they indicate changes in mechanical properties of the fabrics. The morphology of plasma-treated fibers was analyzed by scanning electron microscopy (SEM). SEM images revealed that, when plasma conditions that lead to a decolorization were chosen, specific fiber surface changes were always observed in the form of submicrometer-sized striations, pits, and cracks. Mechanical properties of denim fabrics were moderately influenced by treatment conditions. The results indicated that decolorization was highly affected by plasma parameters and desired `worn look' effects could be designed by adequate control of plasma processing while paying attention to limiting the plasma-induced damage.

Plasma treatment is based on the physico-chemical changes of the material surface and as an ecologically and economically acceptable process it can be an attractive alternative to conventional modifications. The possibilities of plasma technology application to the modification of polymer and textile materials are discussed. Different specific properties of the material can be achieved by plasma cleaning, etching, functionalization or polymerization. The final effects are strongly influenced by the treatment parameters (treatment time, pressure, power, gas flow), the applied gas and nature of the material. The plasma treatment of polymers is predominantly focused on cleaning and activation of the surfaces to increase adhesion, binding, wettability, dye ability and printability. Current studies deal more with plasma polymerization where an ultra thin film of plasma polymer is deposited on the material surface and, depending on the applied monomer, different specific properties can be obtained (i.e. chemical and thermal resistance, abrasion resistance, antireflexion, water repellence, etc.). Plasma application to textiles is mostly oriented toward wool and synthetic fibres, though some studies also consider cotton, hemp, flax and silk. The main goal of plasma treatment is to impart a more hydrophilic fibre surface and accordingly increase wettability, dye ability, printability and particularly, shrink resistance in the case of wool. Recent studies have favored technical textiles, where plasma polymerization can offer a wide range of opportunities.