**7. Plasma and its application in textile industry**

The obtained nonwoven fabric was made of continues microfibers with a uniform diameter

The laser-thinning method has been found to be effective for producing other nonwoven fabrics such as poly(L-lactic acid) and poly(glycolic acid). The schematic of setup is shown in

CO2 laser treatment was used as a novel method for creating antibacterial properties on glass mat by Wiener et al. in 2014. Various types of metallic salts such as CuO, ZnO, and AgNO3 were applied on surface of glass mat and irradiated with the laser light beam (100 *μ*s). Metal particles were deposited on the surface of samples. The antibacterial properties of the fabrics were connected with the presence of metal particles on their surface. Wiener et al. concluded that the change in properties induced by laser can effect an improvement in certain textile

Glass fiber mat surface modifications were carried out using CO2 laser. The geometry of the experiment is visualized in **Figure 9**. In the laser tube (1) produces IR laser beam (2). In the direction of laser beam, computer-adjusted mirror is located (3) which determined the positron of irradiated place on glass fiber mat (4). The temperature of the glass fiber mat on its irradiated side cannot be measured due to high intensity of IR laser beam. So only the temperature of back side of glass fiber mat was estimated (5) by infrared thermometer (6). Laser light treatment

without a droplet.

320 Radiation Effects in Materials

**Figure 8.** CO2 laser-thinning apparatus used for web formation [34].

**Figure 8** [34].

products [35].

Plasma technique can have very important effects on the properties of textile materials. Different types of plasma gases have different effects on the surfaces of textiles. Plasma has many potential for the activation and functionalization of textile materials. Plasma technology is slow but steady in the industrial revolution. Surface modification of textiles cannot replace all wet processes, but it can be a viable pretreatment, which can provide plenty of environ‐ mental and economical benefits. Therefore, textile industry should consider the concept of higher initial investments in equipment that will be paid off quickly with respect to environ‐ ment-related savings and the profit of the sale of high value-added products [37–39].

Improving the fastness properties and antibacterial activity of dyed cotton samples was studied by Shahidi in 2015. In her research, first cotton fabrics were dyed with various types of dyestuffs such as Direct, Vat, and Reactive. Then prepared samples were sputtered using plasma sputtering system for 15 s by silver and copper. For deposition of metal nano layer on the surface of samples, DC magnetron puttering system was used. Samples were placed on the anode. By attacking active ions, radicals, and electrons, the cathode particles were scattered. Silver or copper particles were deposited on the surface of cotton samples, and through incorporation of metal nano particles on fabric surfaces, the antibacterial has been developed. It can be concluded that sputtering technique can be a novel method for improving the fastness properties of dyed cotton samples [38].

DC magnetron sputtering system for creating antibacterial and ultraviolet protective cotton fabrics has been used by Shahidi et al. in 2016. A silver anode and cathode were used. Silver particles were deposited on the both sides of cotton samples, and the antibacterial property has been developed, through sputtering of silver particles on fabric surfaces. Treated cotton fabrics had an excellent UV-blocking property. According to the standard, the treated cotton fabric can claim to be a "UV Protective product." They concluded that the change in properties induced by plasma can effect an improvement in certain textile products [39].

Conventional wet treatment in textile industry involves high consumption and pollution of water resources. Wastewater processing costs are high, and drying the wetted fibers is energy-, time-, and cost-intensive. So the textile industry has a great interest in alternative dry processes. Low temperature plasma treatment is a dry and ecofriendly technology which has been widely used to modify the chemical and topographical properties of polymers and textiles surface. The application of plasma technologies as a pretreatment and finishing process for textiles has become very popular because this surface modification method changes the outermost layer of the substrate without altering the bulk properties. Low-pressure plasma treatments are known to induce physical and chemical surface changes in textile fibers through several concurrent processes (activation, etching, grafting chemical functional groups, and crosslinking).

Girmoldi et al., in 2015, performed atmospheric pressure plasma treatments of pure cashmere and wool/cashmere textiles with a dielectric barrier discharge (DBD) in humid air (air/water vapor mixtures). Their analyses revealed a surface oxidation of the treated fabrics, which enhances their surface wettability with minor etching effects, an essential feature for the maintenance of the textile softness [40].

Air plasma treatment can modify the physical and chemical properties of the surface, and it causes to increase the hydrophilic character of a material. The production of new textile products for cosmetic applications requires pretreatment on the surface of fabrics. In this kind of application, the textile must have some organoleptic and aesthetic properties which require the use of softeners.

Surface modification of the PA66 fibers by low temperature plasma has been studied by Labay et al. in 2014. Corona plasma treatment has been investigated to achieve surface modification in the first nanometers of polymer fibers surface in order to modulate the incorporation and the release of caffeine. Plasma treatment improved the caffeine release [41].

Polyester fiber is one of the most important materials for textile manufacturing. However, the conventional antistatic finishing processes for polyester involve numerous energies and chemicals, with corresponding environmental pollution. The synergetic effects of lowtemperature oxygen plasma (P) and N,O-carboxymethyl chitosan (N) treatments on the antistatic and antibacterial properties of polyester fabrics were investigated by Liu et al. in 2016. They concluded that all the treated polyester fabrics had no obviously antibacterial effect on *E. coli* (Gram-negative). Their findings indicated that the proposed process can provide good antistatic performance for polyester fabrics with a minimum of pollution [42].

Silver or copper particles were deposited on the surface of cotton samples, and through incorporation of metal nano particles on fabric surfaces, the antibacterial has been developed. It can be concluded that sputtering technique can be a novel method for improving the fastness

DC magnetron sputtering system for creating antibacterial and ultraviolet protective cotton fabrics has been used by Shahidi et al. in 2016. A silver anode and cathode were used. Silver particles were deposited on the both sides of cotton samples, and the antibacterial property has been developed, through sputtering of silver particles on fabric surfaces. Treated cotton fabrics had an excellent UV-blocking property. According to the standard, the treated cotton fabric can claim to be a "UV Protective product." They concluded that the change in properties

Conventional wet treatment in textile industry involves high consumption and pollution of water resources. Wastewater processing costs are high, and drying the wetted fibers is energy-, time-, and cost-intensive. So the textile industry has a great interest in alternative dry processes. Low temperature plasma treatment is a dry and ecofriendly technology which has been widely used to modify the chemical and topographical properties of polymers and textiles surface. The application of plasma technologies as a pretreatment and finishing process for textiles has become very popular because this surface modification method changes the outermost layer of the substrate without altering the bulk properties. Low-pressure plasma treatments are known to induce physical and chemical surface changes in textile fibers through several concurrent processes (activation, etching, grafting chemical functional groups, and cross-

Girmoldi et al., in 2015, performed atmospheric pressure plasma treatments of pure cashmere and wool/cashmere textiles with a dielectric barrier discharge (DBD) in humid air (air/water vapor mixtures). Their analyses revealed a surface oxidation of the treated fabrics, which enhances their surface wettability with minor etching effects, an essential feature for the

Air plasma treatment can modify the physical and chemical properties of the surface, and it causes to increase the hydrophilic character of a material. The production of new textile products for cosmetic applications requires pretreatment on the surface of fabrics. In this kind of application, the textile must have some organoleptic and aesthetic properties which require

Surface modification of the PA66 fibers by low temperature plasma has been studied by Labay et al. in 2014. Corona plasma treatment has been investigated to achieve surface modification in the first nanometers of polymer fibers surface in order to modulate the incorporation and

Polyester fiber is one of the most important materials for textile manufacturing. However, the conventional antistatic finishing processes for polyester involve numerous energies and chemicals, with corresponding environmental pollution. The synergetic effects of lowtemperature oxygen plasma (P) and N,O-carboxymethyl chitosan (N) treatments on the antistatic and antibacterial properties of polyester fabrics were investigated by Liu et al. in

the release of caffeine. Plasma treatment improved the caffeine release [41].

induced by plasma can effect an improvement in certain textile products [39].

properties of dyed cotton samples [38].

322 Radiation Effects in Materials

maintenance of the textile softness [40].

linking).

the use of softeners.

In 2016, pure cashmere and wool/nylon textiles were modified by means of an atmospheric pressure plasma treatment with a DBD in humid air followed by a finishing process with a fluorocarbon resin by Zanini et al. Their result indicated a higher amount of fluorocarbon resin on the surface of the fabric which was plasma treated before the finishing process and a more uniform coverage of the fibers of this textile. They concluded that the hydrophilic character of the plasma-activated fabric leads to a higher adsorption of the water-based dispersion that contain the fluorocarbon resin and limit the de-wetting phenomenon of the fibers during the drying step. All these results highlight the importance of the plasma activation step to enhance the hydro- and the oleo-repellent properties of the modified fabrics, as assessed by different analyses (water contact angle, standard tests for hydro- and oleo-repellence, and water adsorption isotherms) [43].

Textile industry wastewater has large amounts of organic dyes that are resistant to the biological methods. Moreover, other physical and chemical processes such as adsorption and coagulation merely transfer contaminants to a secondary phase and require more treatment. Fenton and sonication processes are simple and efficient methods that are applied for the mineralization of various contaminants from polluted water sources. The plasma-treated pyrite (PTP) nanostructures were prepared from natural pyrite (NP) utilizing argon plasma due to its sputtering and cleaning effects resulting in more active surface area by Khataee et al. in 2016. They reported that, environmentally friendly plasma modification of the NP, in situ production of H2O2 and OH radicals, low-leached iron concentration and repeated reusability at the milder pH are the significant benefits of the PTP utilization. The significant advantages of the stable PTP are not needed for adding of H2O2, low-leached iron amount, and application at the milder pH [44].

**Figure 10.** Schematic diagram of the glow discharge plasma system used in Khataee et al. study (2016) [44].
