*Use of Ozone in the Textile Industry DOI: http://dx.doi.org/10.5772/intechopen.81774*

*Textile Industry and Environment*

by ozone [41].

nesses are sufficient [42].

Gashti et al. studied on surface oxidation of cellulose by ozone gas. The aim of the study is to investigate the influence of ozonation on the performance of the fluorocarbon monomer on cotton. As a result of the study, fluorocarbon efficiency on cotton is remarkably improved by ozonation before fluoromonomer grafting. The contact angle tests and microscopic appearances show that contact angle increases because of the higher efficiency of the water repellent polymer on the treated cotton

In Bahtiyari and Benli's study, ozone ultrasound humidifier combines to bleach the cotton fabric before dyeing with green walnut shells. As a result, treated cotton with ozone can be dyed with green walnut shells, and the colors of the natural dyed fabrics are good. Even if no mordanting agent is used in natural dyeing, the fast-

Bahtiyari and Benli proposed a green process line in their paper. In their study,

Erdem and Bahtiyari combined ultrasound and ozone during the pretreatment of cotton slivers. Ultrasound is used in scouring process, and as expected, ozone is for bleaching process. As a result of the study, hydrophilicity of the cotton is achieved by pectinase enzyme/ultrasound combination. Meanwhile, bioscoured cotton is dyed by using pomegranate peel and green tea. In the end of the study, they suggest their process line for production of medical and cosmetic textiles [44]. Benli and Bahtiyari applied ozone to natural dyed cotton fabrics in their study.

Aim of the study is to establish an alternative natural dyeing method without

mordanting agents. Ozonation ways are given below:

cotton fabrics are treated by ozone gas and ultrasound before natural dyeing without mordant (**Figure 5**). Natural dyes are nutshell, orange tree leaves, and alkanet roots. Finally, ozone and ultrasound are used for the pretreatment of cotton before natural dyeing without mordanting agent. At the same time, fastnesses of all the dyed samples are generally sufficient, except light fastness. But light fastness of

dyed samples with pomegranate peels is only sufficient [43].

**22**

**Figure 5.**

*Green process line [43].*


Different ozone application ways present various shades and effects due to chemical structure of natural dyes. Different types of fastnesses are examined in terms of ozone application ways and various mordanting agents. Generally, all dyed samples have high fastness except for light fastnesses. Direct ozonation of wet dyed samples improves the rubbing fastness values [45].

Kan et al. examined the effect of plasma-induced ozone treatment on the color fading of reactive dyed cotton fabric. According to the results, color fading effect is increased by increasing ozonation time, and air ratio has considerable effect on color fading. Color levelness of the ozone-treated fabrics is excellent [5, 46].

Eren et al. studied the color stripping of reactive dyed cotton by ozonation. The parameters are ozonation time and type of reactive dyes. The longest ozonation time gives the best color stripping result. COD value of effluent from ozonation is less than that of conventional reductive treatment [47].

Yiğit et al. discussed ozonation for discharge printing of reactive dyed cotton in their paper. The aim of the study is to use ozone gas instead of reductive agent and caustic soda in discharge printing. Color discharge increases at higher gas flow rates and prolonged ozonation times. According to results, ozone gas can be used for discharge printing. However, contour sharpness of conventional discharge printing is much better than that of ozonation. It is not as excellent as contour sharpness of conventional discharge printing [48].

Zhong et al. investigated color-fading process of sulfur-dyed cotton fabric by a plasma-induced ozone. As the results, the plasma-induced ozone color-fading treatment can be used to remove the color from the dyed fabric and the effect is uniform and even [49].

Perinçek et al. studied the ozonation of jute. The results indicate that the ozonation conditions for the best whiteness degree are fabric at pH 7, 60% WPV, and temperature of 23–25°C. The lignin content and DP values of fabrics are reduced by ozonation [50].

Perinçek et al. also combined ozonation and hydrogen peroxide bleaching in their paper. Linen fabrics are bleached in two steps. First, the linen fabric is treated by ozone. Then, it is bleached by hydrogen peroxide. The treatment conditions are optimized statistically [51].

Kurban et al. examined the ozonation of nettle biofiber in their study. Different bleaching methods are applied to nettle fiber fabric. They are:


As a result of the study, ozonation improves the whiteness of nettle fiber fabric. Among all the bleaching ways, the highest whiteness is obtained from combination of the hydrogen peroxide bleaching and ozonation process [52].

### **3.3 Ozonation of protein fibers**

One of the early studies is about ozonation of wool garments. The aim of the study is to obtain shrink-resisted wool garments and fabric. Therefore, a continuous or batch treater was designed, and wool fabric and garments hung in cabin containing ozone. It was found out that circulation of the vapor around the garments and fabric is inevitable for rapid reaction. Fabric construction is very important for desired degree of shrink resistance. It is claimed that ozone-steam process is a solution to the felting problem of wool [53].

Rahmatinejad et al. discussed innovative hybrid fluorocarbon coating on wool treated with UV/ozone. The application of fluorocarbons on the wool fabrics is a problem because of chemistry and structure of the fiber surface. Therefore, UV/ ozone treatment is proposed as a solution to this problem. Firstly, wool is modified by UV/ozone treatment. Hydrophilicity of treated wool is remarkably better than untreated wool. UV/ozone treatment can be applied to one side of the fabric and hybrid functional fabrics with two different properties on each side of the fabric are thus obtained [54].

The chlorine/Hercosett process is the most common treatment for the wool dyeing. It causes environmental problems because of the pollution of wastewater with absorbable organic halides (AOX). Therefore, ozonation is an alternative surface modification method for improving wool dyeability [6].

Micheal and El-Zaher examined the effect of ultraviolet and ozone combination for different times on wool. As a result of the study, wetting of the wool is improved by the ultraviolet/ozone process because of surface modification. It means that there is an increase in amorphous areas of the treated wool. Ultraviolet/ozone oxidizes cystine bond on the surface of the wool fabrics and generates free radical species. They support dye uptake [6].

Shao et al. investigated the effect of UV/ozone exposure and peroxide pad-batch bleaching on the printability of wool. It is found that peroxide pad-batch bleaching can prevent the yellowness caused by UV/ozone treatment and improved the wettability of the treated wool in a short time. Printability performance of treated wool is similar to that of chlorinated wool [55].

Sargunamani and Selvakumar investigated the effects of ozonation on raw and degummed tassar silk fabrics. Ozone treatment is compared with soap degumming and hydrogen peroxide treatment. Soap treatment of silk is less harsh than ozonation. Peroxide treatment causes lower yellowing index compared to ozonation [6, 56].

Balcı et al. discussed the effects of plasma and ozone treatments on silk in their paper. In this study, raw and degummed silk fabrics are treated with low-frequency oxygen plasma and ozone. The processes are applied to the fabrics individually and alternately. According to the results, fabrics treated with ozone have more yellowing index that of plasma treatment. Increasing the treatment time of plasma and ozonation processes causes increase in yellowness and decrease in whiteness [57].

In this study, Perinçek et al. examined role of the fiber moisture, pH, and treatment time during ozonation on the dyeing properties of Angora rabbit. It is observed that ozonation increases the whiteness degree and dyeability property of the fibers. Ozone oxidizes cysteine linkage in the surface of fiber to cysteic acid [6, 58].

Perinçek et al. combine ozone and ultrasound in their paper. First, Angora rabbit fibers are bleached by ozonation. Then, treated fibers are dyed by the aid of ultrasound. It is indicated that the ozonation and ultrasonic dyeing improves the dyeability of Angora rabbit fiber considerably [59].

Atav and Yurdakul investigated the ozonation of mohair fibers. The optimum conditions of ozonation process are W.P.V. 60%, pH 7, and 30 min. Dyeability of the mohair fibers is improved by ozonation [6].

**25**

*Use of Ozone in the Textile Industry*

treated fabrics are limited [61].

**Figure 6.**

**3.4 Ozonation of the other fibers**

 *3: ozonation + oxidative bleaching + reductive bleaching).*

high-density polyethylene (HDPE) films [62].

functional groups is to support adhesion to the matrix [63].

*DOI: http://dx.doi.org/10.5772/intechopen.81774*

Perinçek et al. discussed bleaching of soybean fabric by different treatments combined with ozonation in their paper. Combined process is ozonation, oxidative,

Consequently, combined bleaching processes improve whiteness and hydrophi-

Hydrophilicity of synthetic polymer surfaces can be accomplished by ozone. The reactive molecules on 3-D structures are covered uniformly during the ozonation. Ozone treats not only the surface and penetrates through the polymer bulk. Ozone self-decomposes rapidly in water producing free radicals, a stronger oxidant than ozone itself. This property was utilized to produce hydrophilic and highly reactive

Yang et al. studied the effect of ozone on aramid fibers. They found out that surface morphology of aramid fabrics does not have obvious change after the treatment. Wicking effect increases slightly with increasing ozonation time. Ozonation treatment does not have significant effect on the tenacity and elongation of the fibers. However, the tenacity and elongation of aramid yarns improve significantly after ozonation and increase with increasing ozonation time. The authors claim that ozonation process extracts foreign matters from the surface of the fiber and establishes oxygen-containing functional groups. The importance of oxygen-containing

Rahmatinejad et al. investigated enhancement in polyester materials' hydrophobicity by surface modification via chemical pretreatment, UV/ozone irradiation, and fluorocarbon finishing combinations. The study concentrates on the application of UV/ozone radiation together with various chemical pretreatments

Benli and Bahtiyari examined dyeing of casein fibers with natural dye after ozonation. Casein fabrics are bleached by ozone. However, whiteness degrees of the

*Steps of bleaching process [60] (1: ozonation + reductive bleaching, 2: ozonation + oxidative bleaching,*

licity degree, wettability of the soybean fabrics significantly [60].

and reductive bleaching. Process steps are shown in **Figure 6**.

Perinçek et al. discussed bleaching of soybean fabric by different treatments combined with ozonation in their paper. Combined process is ozonation, oxidative, and reductive bleaching. Process steps are shown in **Figure 6**.

#### **Figure 6.**

*Textile Industry and Environment*

**3.3 Ozonation of protein fibers**

tion to the felting problem of wool [53].

species. They support dye uptake [6].

is similar to that of chlorinated wool [55].

modification method for improving wool dyeability [6].

thus obtained [54].

One of the early studies is about ozonation of wool garments. The aim of the study is to obtain shrink-resisted wool garments and fabric. Therefore, a continuous or batch treater was designed, and wool fabric and garments hung in cabin containing ozone. It was found out that circulation of the vapor around the garments and fabric is inevitable for rapid reaction. Fabric construction is very important for desired degree of shrink resistance. It is claimed that ozone-steam process is a solu-

Rahmatinejad et al. discussed innovative hybrid fluorocarbon coating on wool treated with UV/ozone. The application of fluorocarbons on the wool fabrics is a problem because of chemistry and structure of the fiber surface. Therefore, UV/ ozone treatment is proposed as a solution to this problem. Firstly, wool is modified by UV/ozone treatment. Hydrophilicity of treated wool is remarkably better than untreated wool. UV/ozone treatment can be applied to one side of the fabric and hybrid functional fabrics with two different properties on each side of the fabric are

The chlorine/Hercosett process is the most common treatment for the wool dyeing. It causes environmental problems because of the pollution of wastewater with absorbable organic halides (AOX). Therefore, ozonation is an alternative surface

Micheal and El-Zaher examined the effect of ultraviolet and ozone combination for different times on wool. As a result of the study, wetting of the wool is improved by the ultraviolet/ozone process because of surface modification. It means that there is an increase in amorphous areas of the treated wool. Ultraviolet/ozone oxidizes cystine bond on the surface of the wool fabrics and generates free radical

Shao et al. investigated the effect of UV/ozone exposure and peroxide pad-batch bleaching on the printability of wool. It is found that peroxide pad-batch bleaching can prevent the yellowness caused by UV/ozone treatment and improved the wettability of the treated wool in a short time. Printability performance of treated wool

Sargunamani and Selvakumar investigated the effects of ozonation on raw and degummed tassar silk fabrics. Ozone treatment is compared with soap degumming and hydrogen peroxide treatment. Soap treatment of silk is less harsh than ozonation. Peroxide treatment causes lower yellowing index compared to ozonation [6, 56]. Balcı et al. discussed the effects of plasma and ozone treatments on silk in their paper. In this study, raw and degummed silk fabrics are treated with low-frequency oxygen plasma and ozone. The processes are applied to the fabrics individually and alternately. According to the results, fabrics treated with ozone have more yellowing index that of plasma treatment. Increasing the treatment time of plasma and ozona-

tion processes causes increase in yellowness and decrease in whiteness [57].

Ozone oxidizes cysteine linkage in the surface of fiber to cysteic acid [6, 58]. Perinçek et al. combine ozone and ultrasound in their paper. First, Angora rabbit fibers are bleached by ozonation. Then, treated fibers are dyed by the aid of ultrasound. It is indicated that the ozonation and ultrasonic dyeing improves the

dyeability of Angora rabbit fiber considerably [59].

mohair fibers is improved by ozonation [6].

In this study, Perinçek et al. examined role of the fiber moisture, pH, and treatment time during ozonation on the dyeing properties of Angora rabbit. It is observed that ozonation increases the whiteness degree and dyeability property of the fibers.

Atav and Yurdakul investigated the ozonation of mohair fibers. The optimum conditions of ozonation process are W.P.V. 60%, pH 7, and 30 min. Dyeability of the

**24**

*Steps of bleaching process [60] (1: ozonation + reductive bleaching, 2: ozonation + oxidative bleaching, 3: ozonation + oxidative bleaching + reductive bleaching).*

Consequently, combined bleaching processes improve whiteness and hydrophilicity degree, wettability of the soybean fabrics significantly [60].

Benli and Bahtiyari examined dyeing of casein fibers with natural dye after ozonation. Casein fabrics are bleached by ozone. However, whiteness degrees of the treated fabrics are limited [61].

#### **3.4 Ozonation of the other fibers**

Hydrophilicity of synthetic polymer surfaces can be accomplished by ozone. The reactive molecules on 3-D structures are covered uniformly during the ozonation. Ozone treats not only the surface and penetrates through the polymer bulk. Ozone self-decomposes rapidly in water producing free radicals, a stronger oxidant than ozone itself. This property was utilized to produce hydrophilic and highly reactive high-density polyethylene (HDPE) films [62].

Yang et al. studied the effect of ozone on aramid fibers. They found out that surface morphology of aramid fabrics does not have obvious change after the treatment. Wicking effect increases slightly with increasing ozonation time. Ozonation treatment does not have significant effect on the tenacity and elongation of the fibers. However, the tenacity and elongation of aramid yarns improve significantly after ozonation and increase with increasing ozonation time. The authors claim that ozonation process extracts foreign matters from the surface of the fiber and establishes oxygen-containing functional groups. The importance of oxygen-containing functional groups is to support adhesion to the matrix [63].

Rahmatinejad et al. investigated enhancement in polyester materials' hydrophobicity by surface modification via chemical pretreatment, UV/ozone irradiation, and fluorocarbon finishing combinations. The study concentrates on the application of UV/ozone radiation together with various chemical pretreatments on fabrics and their effects on the fluorocarbon finishing performance. In surface modification, UV/ozone irradiation prior to fluorocarbon treatment results in more hydrophobic polyester fiber surface than only fluorocarbon-treated fabric. Because of erosion, redeposition, and the melting effects of UV/ozone-irradiation, proper unevenness of the fiber surface is formed by UV/ozone radiation [64].

Elnagar et al. studied dyeability of polyester and nylon fabrics treated with UV/ ozone radiation. Mordant is ferrous sulfate. Natural dyes are curcumin and saffron dyes. The results show that dyeability of both fabrics with curcumin and saffron natural dyes increases with aid of UV/ozone [65, 66].

Atav and Namırtı investigated effect of ozonation process on dyeing of polyamide fabrics with walnut rind natural dye. Color yield is increased by ozonation before dyeing polyamide fabric, and ozone gas does not affect the color nuance and fastness properties negatively [67].

Lee et al. discussed ozone-gas treatment of nylon 6 and polyester fabrics in their paper. It is appeared that the O1s relative intensity increases for nylon 6 and polyester fabrics. Oxygen is included in the form of OCOH and OCOOH. Therefore, hydrophilicity of treated fabrics is higher than untreated ones. Ozonation changes the crystalline and amorphous regions, especially for polyester fiber. Moisture regain, water absorption, and dyeing properties increase despite an increase in the crystallinity. On the other hand, ozonation affects the brittle hand of the fabric [68].

Lee et al. studied ozonation of cationic dyeable polyester and poly(butylene terephthalate) fibers too. Although water absorption is improved by ozonation, crystallinity index increases a little bit. They claim that ozonation changes fiber surface. On the other hand, internal structure of both fibers is also changed by the treatment. Therefore, it has effect on the dyeing properties of the fibers. After ozonation, dyeing rate with the cationic dye increases exceptionally. However, increasing dyeing rate with disperse dye is not so significant [69].

Eren and Aniş suggest ozone treatment of polyethylene terephthalate fibers after dyeing as a novel after-clearing method. Results indicate that the trimer removal rates of ozone treatment are quite similar to the conventional reduction clearing for 1-min and higher for 3-min ozone treatments. The treatment time at 130°C is also efficient on the amount of surface trimer [70].

Eren studied on combination of after-clearing and decolorization by ozonation after disperse dyeing of polyester. He claims that encouraging results from decolorization and wash fastness tests are obtained with a 3-min ozonation period in the dyebath at room temperature. Decolorization and COD removal ratios are up to 67 and 62%, respectively [71].

Eren et al. discussed after-clearing of disperse dyed polyester with gaseous ozone in their paper. They propose that a new ozonation method is adopted to continuous treatment lines. Proposed method is different from exhaust application method in early papers [71, 72]. Ozone gas from the generator blasts through the wet fabric. Depending on the type of the disperse dyes, ozonation time is different for wash fastness results which is comparable to that of conventional reduction clearing method. According to results from tensile strength tests and scanning electron microscopy analysis, ozonation does not cause any serious damage to the fabrics [73].

#### **3.5 Advantages and disadvantages of use of ozone in the textile industry**

Wet processing of textile materials consumes large amounts of electricity, fuel, and water. Therefore, greenhouse gas emissions and contaminated effluent are environmental problem. Ozone treatment proposed a solution to environmental pollution from textile wet processes [5, 74, 75]. Use of ozone in the textile industry has advantages and limitations [4].

**27**

*Use of Ozone in the Textile Industry*

*DOI: http://dx.doi.org/10.5772/intechopen.81774*

conventional wet processes,

• improving dyeability of fibers,

reductive washing, etc.

high oxidation potential of ozone,

• flammability and explosivity of ozone.

• high capital investment for new machinery setups,

• necessity of onsite generation because of unsuitable for storage,

• use of ozone in illiterate way due to occupational health and safety,

[4]. However, limitations of the ozone have not to be forgotten by users.

• needs regular monitoring and alarm system in the mill for any leakages, and

Finally, ozonation within a closed system can be called as environmental process

• unsuitable for storage due to decomposition of ozone quickly,

wet processes,

potential of ozone,

Advantages of ozonation in the textile industry [4, 5, 13, 74]:

• no halogenated organic compounds (AOX) in waste water,

• different pattern and fading effects soon in denim washing,

• more ecological antifelting treatment than conventional methods,

bib, hydrophilic cotton, etc., due to disinfectant property of ozone.

• high strength loss in textile materials due to illiterate use of ozone,

• treatment of hygienic nondurable products like sheets, gauze bandage, tissues,

• prevention of yellowing problem with after-treatment like catalase treatment,

• difficulty in using ozone gas due to suitability of textile finishing machine for

• except for stainless steel, corrosion in metal parts of finishing machine due to

• damage possibility of plastics of the finishing machine due to high oxidation

• higher whiteness than conventional bleaching processes, and

Limitations of ozone treatment [4, 5, 13, 14, 32, 74, 76, 77]:

• lower water and chemical consumption and time loss of ozonation process than

• no need to store chemicals compared to the other conventional methods,

• no dangerous waste because of decomposition of ozone into oxygen,

• combination with novel technologies like UV, plasma, and ultrasound,

*Textile Industry and Environment*

on fabrics and their effects on the fluorocarbon finishing performance. In surface modification, UV/ozone irradiation prior to fluorocarbon treatment results in more hydrophobic polyester fiber surface than only fluorocarbon-treated fabric. Because of erosion, redeposition, and the melting effects of UV/ozone-irradiation, proper

Elnagar et al. studied dyeability of polyester and nylon fabrics treated with UV/ ozone radiation. Mordant is ferrous sulfate. Natural dyes are curcumin and saffron dyes. The results show that dyeability of both fabrics with curcumin and saffron

Atav and Namırtı investigated effect of ozonation process on dyeing of polyamide fabrics with walnut rind natural dye. Color yield is increased by ozonation before dyeing polyamide fabric, and ozone gas does not affect the color nuance and

Lee et al. discussed ozone-gas treatment of nylon 6 and polyester fabrics in their paper. It is appeared that the O1s relative intensity increases for nylon 6 and polyester fabrics. Oxygen is included in the form of OCOH and OCOOH. Therefore, hydrophilicity of treated fabrics is higher than untreated ones. Ozonation changes the crystalline and amorphous regions, especially for polyester fiber. Moisture regain, water absorption, and dyeing properties increase despite an increase in the crystallinity. On the other hand, ozonation affects the brittle hand of the fabric [68]. Lee et al. studied ozonation of cationic dyeable polyester and poly(butylene terephthalate) fibers too. Although water absorption is improved by ozonation, crystallinity index increases a little bit. They claim that ozonation changes fiber surface. On the other hand, internal structure of both fibers is also changed by the treatment. Therefore, it has effect on the dyeing properties of the fibers. After ozonation, dyeing rate with the cationic dye increases exceptionally. However,

Eren and Aniş suggest ozone treatment of polyethylene terephthalate fibers after dyeing as a novel after-clearing method. Results indicate that the trimer removal rates of ozone treatment are quite similar to the conventional reduction clearing for 1-min and higher for 3-min ozone treatments. The treatment time at 130°C is also

Eren studied on combination of after-clearing and decolorization by ozonation after disperse dyeing of polyester. He claims that encouraging results from decolorization and wash fastness tests are obtained with a 3-min ozonation period in the dyebath at room temperature. Decolorization and COD removal ratios are up to 67

Eren et al. discussed after-clearing of disperse dyed polyester with gaseous ozone in their paper. They propose that a new ozonation method is adopted to continuous treatment lines. Proposed method is different from exhaust application method in early papers [71, 72]. Ozone gas from the generator blasts through the wet fabric. Depending on the type of the disperse dyes, ozonation time is different for wash fastness results which is comparable to that of conventional reduction clearing method. According to results from tensile strength tests and scanning electron microscopy

analysis, ozonation does not cause any serious damage to the fabrics [73].

**3.5 Advantages and disadvantages of use of ozone in the textile industry**

Wet processing of textile materials consumes large amounts of electricity, fuel, and water. Therefore, greenhouse gas emissions and contaminated effluent are environmental problem. Ozone treatment proposed a solution to environmental pollution from textile wet processes [5, 74, 75]. Use of ozone in the textile industry

unevenness of the fiber surface is formed by UV/ozone radiation [64].

increasing dyeing rate with disperse dye is not so significant [69].

efficient on the amount of surface trimer [70].

and 62%, respectively [71].

has advantages and limitations [4].

natural dyes increases with aid of UV/ozone [65, 66].

fastness properties negatively [67].

**26**

Advantages of ozonation in the textile industry [4, 5, 13, 74]:


Limitations of ozone treatment [4, 5, 13, 14, 32, 74, 76, 77]:


Finally, ozonation within a closed system can be called as environmental process [4]. However, limitations of the ozone have not to be forgotten by users.

*Textile Industry and Environment*
