**4.1 Textile fibres with whey protein**

The use of milk proteins for fibre production and application in textile industry remotes back to the beginning of the twentieth century. The conventional fibre production method consists in dissolving 20–25% milk proteins, including whey protein and its fractions, in a 2% NaOH solution to obtain a solution of adequate viscosity for fibre production by wet spinning extrusion (10–30% solid material) [48, 49]. In this process, the protein solution is pumped through a spinneret into an acid bath with a pH below the isoelectric point of the protein (4.5–4.6) to cause its coagulation [48, 50, 51]. The coagulate is afterwards stretched and drawn to increase polymer chain orientation and tensile strength of the fibre. Coagulation baths, containing aluminium salts of formaldehyde, may further increase the fibre stretching and enhance its physical properties [48, 51].

There are already several studies and patents on the production of fibres from whey proteins aiming to obtain fibres with improved mechanical properties and

to use of more ecological productive processes. Kamada et al. produced fibres from β-lactoglobulin nanofibrils in the presence of alcohols, low pH and elevated temperature (hydrolysis of the protein in low molecular weight peptides for the formation of nanofibrils) [52]. Sullivan et al. produced nanofibres, by electrospinning, from WPI solutions (75%) and polyethylene oxide (PEO) (4%) and solutions of β-lactoglobulin (75%) and PEO (10%) in water [53]. Drosou et al. [54] studied the possibility to make whey protein fibres by electrospinning. However, electrospinning of nanofibres from proteins has proven to be quite challenging due to their globular nature, in most cases, the low viscosity of their aqueous solutions and potential lack of intermolecular entanglements [54]. To overcome these challenges, blends of proteins and other bio-based materials have been used. Drosou also tested some WPI/pullulan blends and was able to obtain continuous and uniform fibres [54]. The presence of the pullulan increased the viscosity of the solution, having a big impact in the process parameters. Zhong et al. adopted a similar strategy to obtain also whey protein nanofibres through electrospinning [55]. In this case the authors blended the whey protein with PEO and were not able to produce pure protein fibres. The ability of the whey protein solutions to produce fibres changed over time after dissolution [55]. Oktar et al. produced fibres from WPC blended with poly-ε-caprolactone (80 kDa) [56]. The obtained fibres showed improved mechanical properties to higher WPC concentrations (3–8% w/v). Kutzli et al. produced whey protein fibres by electrospinning, blending the proteins with enzymatically treated starch (maltodextrin) [57]. Using two different maltodextrins, with different molecular weights, the authors found that the spinnability of the solution is heavily dependent on the average size of the maltodextrin. Aman Mohammadi et al. obtained whey protein fibres by electrospinning, mixing WPI and guar gum [58].

As already mentioned, fibres resulting from these processes usually fail to have the mechanical properties for weaving and textile production. For this reason, whey protein fibres are often mixed with other fibres with appropriate mechanical properties (mostly cotton, silk and wool, with tensile strengths) [59].

The valorization of by-products of the dairy industry by wet spinning generates corrosive effluents rich in metal salts. This type of effluent requires appropriate conditioning and downstream steps of neutralization and precipitation of metals, which may entail large costs for its treatment and disposal (in order to avoid acidification of soils and water resources, increase of the dissolved salt content and the appearance of health problems in animals and humans resulting from untreated discards in water bodies used to supply populations) [60].

#### **4.2 Textile finishing with whey protein**

Whey proteins have also been studied for their applicability as coatings and additives in the textile industry. Pisitsak et al. (2015) studied the dyeability increase of cotton for a tannin-rich dye extracted from *Xylocarpus granatum* bark. Cotton fabrics were pretreated with WPI by a padding technique. The improvement in the dye absorption after protein pretreatment is ascribed to the insoluble complex formation between the tannin and the proteins present in the fabric, stabilized through hydrogen bonding and hydrophobic interactions, which makes it easy to be coloured. Besides that, both protein treatment and dyeing improved the ultraviolet (UV) shielding efficiency of the cotton fabrics [61].

Proteins are not the only milk component able to facilitate the dyeing process. Dyes are generally applied in an aqueous solution, and some of them require chemical auxiliaries to improve their water solubility and to improve the dyeing process. Bianchini et al. [62] reported a study to naturalize two synthetic azadyes through

**113**

*Innovation of Textiles through Natural By-Products and Wastes*

cial), improving efficacy and reducing waste [62].

to destroy dyes [62].

landfill confinement [57, 58].

horizontal configuration [63].

their linkage with lactose to induce their water solubility. In this study, a chromophore was transformed into a hydrosoluble species through glycol conjugation with a sugar, and a preliminary tinctorial test was carried out with polyester, cotton, acetate, wool and acrylic fabrics. Results showed several benefits since the modification of the dyes with lactose, as this improved their water solubility, allowing the elimination of surfactants and mordants, making the dyeing process easier and avoiding high temperatures and high pressures. Besides that, the new hydrosoluble dyes showed a better affinity towards different fabrics (synthetic, natural, artifi-

These developments brought benefits not only in terms of textile valorization but also in terms of the use and recovery of wastes and by-products. The utilization of carbohydrates largely and cheaply available, such as D-glucose, D-galactose and lactose, normally discarded in huge quantities in the environment, with no negligible impact, brings new possibilities for efficient and more selective waste treatment by using, for instance, live micro-organisms to attack the sugar moiety and consequently the covalently bonded chromophore, or the use of enzymes able

In the past years, novel and innovative solutions for flame retardant systems, for replacing the traditional additives, have been explored. In particular, the availability of a formaldehyde-free flame retardant system based on natural macromolecules such as proteins could be extremely interesting for a possible industrial application [63]. Considering the environmental concern, more ecological and effective solutions have been studied, in the field of flame retardancy, since the solutions mostly used are based on halogenates or phosphorus, being persistent and bioaccumulating in the soil and even carcinogenic and/or toxic for animals and humans. In this sense, biomacromolecules have aroused interest as a green solution in this field, particularly whey proteins and caseins. In addition to being biological additives, they can have added value, as they can be considered by-products or even wastes from the agro-food industry and their recoveries and subsequent use as flame retardants may comply with the current needs of valorization of agro-food crops, avoiding their

Therefore, different novel strategies have been designed in order to enable the use of green flame retardant systems. Due to the ability of whey proteins to act as water vapour absorbers and as oxygen barriers, textiles treated with this by-product have been exploited in order to increase their thermal stability and flame retardancy [63]. For this, folded and unfolded whey protein isolates were deposited on cotton fabrics. Through thermogravimetric analysis it was observed that whey protein coatings significantly affected the thermal degradation of cotton in an inert and oxidative atmosphere. Specifically, the application of whey protein coating contributed to the delay of the thermal degradation of the textile, also resulting in a smaller total mass loss. Besides that, the treated fabrics have shown a decrease of burning rate and an increase of total burning time, determined by the flammability tests in

The antibacterial properties of some of the whey components have also been studied. Through the cross-linking between microbial transglutaminase (mTGase) and lactoferrin, the antibacterial properties of wool were improved to *E. coli* (Gramnegative) and *S. aureus* (Gram-positive) bacteria. It was observed that the amount of lactoferrin deposited on the wool fabric was improved with the cross-linking reaction with mTGase, when compared to the control sample. The wool fabrics immobilized with lactoferrin exhibited approximately 70 and 60% inhibition for *E.* 

*coli* and *S. aureus*, respectively, showing a good antibacterial property [64]. The same was observed in a recent study developed by Srisod et al. [65]. It was described the utilization of WPI as reducing and stabilizing agent in a green

*DOI: http://dx.doi.org/10.5772/intechopen.93011*

### *Innovation of Textiles through Natural By-Products and Wastes DOI: http://dx.doi.org/10.5772/intechopen.93011*

*Waste in Textile and Leather Sectors*

and guar gum [58].

to use of more ecological productive processes. Kamada et al. produced fibres from β-lactoglobulin nanofibrils in the presence of alcohols, low pH and elevated temperature (hydrolysis of the protein in low molecular weight peptides for the formation of nanofibrils) [52]. Sullivan et al. produced nanofibres, by electrospinning, from WPI solutions (75%) and polyethylene oxide (PEO) (4%) and solutions of β-lactoglobulin (75%) and PEO (10%) in water [53]. Drosou et al. [54] studied the possibility to make whey protein fibres by electrospinning. However, electrospinning of nanofibres from proteins has proven to be quite challenging due to their globular nature, in most cases, the low viscosity of their aqueous solutions and potential lack of intermolecular entanglements [54]. To overcome these challenges, blends of proteins and other bio-based materials have been used. Drosou also tested some WPI/pullulan blends and was able to obtain continuous and uniform fibres [54]. The presence of the pullulan increased the viscosity of the solution, having a big impact in the process parameters. Zhong et al. adopted a similar strategy to obtain also whey protein nanofibres through electrospinning [55]. In this case the authors blended the whey protein with PEO and were not able to produce pure protein fibres. The ability of the whey protein solutions to produce fibres changed over time after dissolution [55]. Oktar et al. produced fibres from WPC blended with poly-ε-caprolactone (80 kDa) [56]. The obtained fibres showed improved mechanical properties to higher WPC concentrations (3–8% w/v). Kutzli et al. produced whey protein fibres by electrospinning, blending the proteins with enzymatically treated starch (maltodextrin) [57]. Using two different maltodextrins, with different molecular weights, the authors found that the spinnability of the solution is heavily dependent on the average size of the maltodextrin. Aman Mohammadi et al. obtained whey protein fibres by electrospinning, mixing WPI

As already mentioned, fibres resulting from these processes usually fail to have the mechanical properties for weaving and textile production. For this reason, whey protein fibres are often mixed with other fibres with appropriate mechanical

The valorization of by-products of the dairy industry by wet spinning generates corrosive effluents rich in metal salts. This type of effluent requires appropriate conditioning and downstream steps of neutralization and precipitation of metals, which may entail large costs for its treatment and disposal (in order to avoid acidification of soils and water resources, increase of the dissolved salt content and the appearance of health problems in animals and humans resulting from untreated

Whey proteins have also been studied for their applicability as coatings and additives in the textile industry. Pisitsak et al. (2015) studied the dyeability increase of cotton for a tannin-rich dye extracted from *Xylocarpus granatum* bark. Cotton fabrics were pretreated with WPI by a padding technique. The improvement in the dye absorption after protein pretreatment is ascribed to the insoluble complex formation between the tannin and the proteins present in the fabric, stabilized through hydrogen bonding and hydrophobic interactions, which makes it easy to be coloured. Besides that, both protein treatment and dyeing improved the ultraviolet

Proteins are not the only milk component able to facilitate the dyeing process. Dyes are generally applied in an aqueous solution, and some of them require chemical auxiliaries to improve their water solubility and to improve the dyeing process. Bianchini et al. [62] reported a study to naturalize two synthetic azadyes through

properties (mostly cotton, silk and wool, with tensile strengths) [59].

discards in water bodies used to supply populations) [60].

(UV) shielding efficiency of the cotton fabrics [61].

**4.2 Textile finishing with whey protein**

**112**

their linkage with lactose to induce their water solubility. In this study, a chromophore was transformed into a hydrosoluble species through glycol conjugation with a sugar, and a preliminary tinctorial test was carried out with polyester, cotton, acetate, wool and acrylic fabrics. Results showed several benefits since the modification of the dyes with lactose, as this improved their water solubility, allowing the elimination of surfactants and mordants, making the dyeing process easier and avoiding high temperatures and high pressures. Besides that, the new hydrosoluble dyes showed a better affinity towards different fabrics (synthetic, natural, artificial), improving efficacy and reducing waste [62].

These developments brought benefits not only in terms of textile valorization but also in terms of the use and recovery of wastes and by-products. The utilization of carbohydrates largely and cheaply available, such as D-glucose, D-galactose and lactose, normally discarded in huge quantities in the environment, with no negligible impact, brings new possibilities for efficient and more selective waste treatment by using, for instance, live micro-organisms to attack the sugar moiety and consequently the covalently bonded chromophore, or the use of enzymes able to destroy dyes [62].

In the past years, novel and innovative solutions for flame retardant systems, for replacing the traditional additives, have been explored. In particular, the availability of a formaldehyde-free flame retardant system based on natural macromolecules such as proteins could be extremely interesting for a possible industrial application [63]. Considering the environmental concern, more ecological and effective solutions have been studied, in the field of flame retardancy, since the solutions mostly used are based on halogenates or phosphorus, being persistent and bioaccumulating in the soil and even carcinogenic and/or toxic for animals and humans. In this sense, biomacromolecules have aroused interest as a green solution in this field, particularly whey proteins and caseins. In addition to being biological additives, they can have added value, as they can be considered by-products or even wastes from the agro-food industry and their recoveries and subsequent use as flame retardants may comply with the current needs of valorization of agro-food crops, avoiding their landfill confinement [57, 58].

Therefore, different novel strategies have been designed in order to enable the use of green flame retardant systems. Due to the ability of whey proteins to act as water vapour absorbers and as oxygen barriers, textiles treated with this by-product have been exploited in order to increase their thermal stability and flame retardancy [63]. For this, folded and unfolded whey protein isolates were deposited on cotton fabrics. Through thermogravimetric analysis it was observed that whey protein coatings significantly affected the thermal degradation of cotton in an inert and oxidative atmosphere. Specifically, the application of whey protein coating contributed to the delay of the thermal degradation of the textile, also resulting in a smaller total mass loss. Besides that, the treated fabrics have shown a decrease of burning rate and an increase of total burning time, determined by the flammability tests in horizontal configuration [63].

The antibacterial properties of some of the whey components have also been studied. Through the cross-linking between microbial transglutaminase (mTGase) and lactoferrin, the antibacterial properties of wool were improved to *E. coli* (Gramnegative) and *S. aureus* (Gram-positive) bacteria. It was observed that the amount of lactoferrin deposited on the wool fabric was improved with the cross-linking reaction with mTGase, when compared to the control sample. The wool fabrics immobilized with lactoferrin exhibited approximately 70 and 60% inhibition for *E. coli* and *S. aureus*, respectively, showing a good antibacterial property [64].

The same was observed in a recent study developed by Srisod et al. [65]. It was described the utilization of WPI as reducing and stabilizing agent in a green synthesis of silver nanoparticles (AgNps) from silver nitrate. In addition, a natural tannin-rich extract was applied to cross-link the WPI/AgNps to cotton fabric through the formation of an insoluble binder. The cotton fabric treated showed an excellent antibacterial performance against *S. aureus*, even after 50 washing cycles, showing no toxicity to L929 cell changes to the intrinsic properties of the substrate (drapeability and tearing strength) [65].

Regarding the globular structure of whey proteins, due to their properties and structures, they have been used as a vehicle for active substances such as antimicrobials, antioxidants and drugs, among others, for the development of new functional products [66–69]. This approach is widely used in several industrial sectors, providing the possibility of a controlled release of bioactive compounds. It can easily be applied to the textile industry, with the possibility to add functionality to textiles.

The antioxidant effects of vitamin E encapsulated in BSA nanoparticles in cotton have already been studied [70]. The nanoparticles, produced by ultrasonic emulsification, have a size between 200 and 300 nm and have the capacity to encapsulate 99% of the vitamin. After impregnation onto cotton fabrics, they present an antioxidant activity and wash resistance up to ten cycles [71].

Microspheres of BSA have also been tested as encapsulation agents of an antibiotic, tetracycline, in order to obtain an antibacterial coating for cotton and polyester fabrics [72]. These capsules demonstrated not only good encapsulation capacity but also gave the textiles antimicrobial properties [72].

Nonetheless, these types of applications at an industrial level have some limitations since the cost-effectiveness ratio of these biomacromolecules may not compensate until now. In addition, the durability to the laundering was not yet achieved in an effectively sustainable and long-lasting way, since these biomacromolecules have a waterborne character and these coatings come off from the textile when subjected to washing. When adding binding agents to biomacromolecules, a balance must be sought between their green characteristics and the use of chemicals that do not eradicate the sustainability of the process. In this sense, exploitation of biologically derived chemical treatments, or at least chemicals with a low environmental impact, which could make the proposed biomacromolecules more durable than they are today, while maintaining their effective functionalities, is being carried out [73, 74].

#### **4.3 Textile coating as a sustainable alternative to genuine leather**

Genuine leather is made of animal skin, namely, bovine leather, tanned and finished with products of synthetic origin (chromium). It is used as a noble material for the manufacture of various products with applications in various industries, such as fashion, fashion accessories, footwear, decoration, automobiles, etc., and is the one that has the greatest expression in the market due to its excellent properties such as porosity, breathability, softness, comfort and fall, among others [75, 76]. Ecological leather refers to a leather tanning process that does not use metals such as chromium but in alternative recurs to substances of natural origin (vegetable, animal or mineral), such as vegetable tannins (polyphenols of plant origin) [77]. Though ecological leather has a lesser environmental impact than genuine leather, it still does not have the same properties of thermal resistance, colour fixation and versatility as the leather resulting from the treatment of tanning with chromium [75]. In addition, there are several ethical and environmental concerns involved in the use of genuine and ecological leather, such as the killing of animals and the high environmental impact resulting from their processing, which have triggered the growing interest on the part of the consumer in more sustainable alternative solutions to leather of animal origin ethically and environmentally. This generated

**115**

and furniture [92].

*Innovation of Textiles through Natural By-Products and Wastes*

income in indigenous and traditional communities [78–80].

abrasion and resistant to ignition by cigarettes [82–84].

furniture, car upholstery lining, etc. [76, 85–90].

a search for alternative solutions with the same performance of genuine leather, which catapulted textile industries towards sustainable innovation as a means of

Vegetable leather is a sustainable product of plant origin resulting from the use of vegetable wastes or by-products. There are already some alternatives of vegetable leather on the market to replace animal leather, although they do not fully reproduce the characteristics of animal leather. Of the solutions on the market, the main

Latex-based leather is the name given to a fabric made up of two renewable raw materials, the latex extracted from the rubber tree (*Hevea brasiliensis*) from the Amazonian forests and cotton. The cotton is impregnated with latex, natural rubber (primary product of the smoking of latex extracted from the rubber tree). These can be used in the production of bags, wallets, clothing, footwear and other objects usually produced in leather. The commercialization of these products has become a reason for hope for the improvement of the life of rubber tappers, their permanence in the forest and the sustainable development of the Amazon, generating work and

The company Ananas Anam has developed an innovative, natural and sustainable non-woven leather called Piñatex™, produced from pineapple leaf fibres, considered as a vegan alternative to traditional leather. From the pineapple leaf fibres, screens are obtained, which can be dyed, printed and treated to obtain different textures [81]. The material is strong, versatile (different colours, patterns, textures, thicknesses), breathable, smooth, light, flexible, sewable, resistant to water and

Products based on thin sheets of cork, laminated with a textile substrate that gives it resistance, are increasingly being introduced to the market as a sustainable vegan alternative to traditional/synthetic leather. They have characteristics equivalent to leather, such as resistance, lightness, breathability, malleability, thermal insulation and impermeability, adding the properties of low density and thermal conductivity. There are several products based on cork leather (cork sheet) on the market, created and launched by designers/brands and national reference companies, such as Bleed—We bleed for nature, Pelcor, and Artelusa, and international, such as Chanel, inter Louboutin, Stella McCartney, Yves Saint Laurent, Prada, Dior, Manolo Blahnik, Dolce & Gabbana and Gucci. These products are based on fashion accessories (wallets, belts, etc.), clothing, umbrellas, footwear, sports goods,

Wood-based leather is similar to cork but made from wood from fast-growing trees, such as oak bark, treated with non-toxic chemicals to make it durable, flexible and malleable. Wood leather can be as thick as genuine leather. Dolce & Gabbana is a market reference that has already used this material in a recent collection of bags and shoes [41]. The German shoe brand nat-2TM also recently launched a line of shoes in which up to 90% of the upper surface of the shoe is covered with wood, which is applied over an organic cotton, in order to become a flexible, soft material that allows to smell the wood and observe its natural texture [91]. Another solution is Wooden Textiles, created by Elisa Strozyk. These materials, which also bear some resemblance to leather, are obtained after cutting thin sheets of wood into pieces and adhering them to a textile substrate. The result is a material that smells like wood, but with some flexibility and softness. There are applications in decoration

Vegea® is a biomaterial produced by the Italian company Vegea, founded by Gianpiero Tessitore and Francesco Merlino [86, 87]. This material, with a similar aspect to leather, valorizes residues from bagasse (skins and tales from grapes), and does not use water in its production [74]. This leather, also known as WineLeather,

*DOI: http://dx.doi.org/10.5772/intechopen.93011*

answering the markets' demands.

examples are presented.

*Waste in Textile and Leather Sectors*

(drapeability and tearing strength) [65].

antioxidant activity and wash resistance up to ten cycles [71].

**4.3 Textile coating as a sustainable alternative to genuine leather**

Genuine leather is made of animal skin, namely, bovine leather, tanned and finished with products of synthetic origin (chromium). It is used as a noble material for the manufacture of various products with applications in various industries, such as fashion, fashion accessories, footwear, decoration, automobiles, etc., and is the one that has the greatest expression in the market due to its excellent properties such as porosity, breathability, softness, comfort and fall, among others [75, 76]. Ecological leather refers to a leather tanning process that does not use metals such as chromium but in alternative recurs to substances of natural origin (vegetable, animal or mineral), such as vegetable tannins (polyphenols of plant origin) [77]. Though ecological leather has a lesser environmental impact than genuine leather, it still does not have the same properties of thermal resistance, colour fixation and versatility as the leather resulting from the treatment of tanning with chromium [75]. In addition, there are several ethical and environmental concerns involved in the use of genuine and ecological leather, such as the killing of animals and the high environmental impact resulting from their processing, which have triggered the growing interest on the part of the consumer in more sustainable alternative solutions to leather of animal origin ethically and environmentally. This generated

also gave the textiles antimicrobial properties [72].

synthesis of silver nanoparticles (AgNps) from silver nitrate. In addition, a natural tannin-rich extract was applied to cross-link the WPI/AgNps to cotton fabric through the formation of an insoluble binder. The cotton fabric treated showed an excellent antibacterial performance against *S. aureus*, even after 50 washing cycles, showing no toxicity to L929 cell changes to the intrinsic properties of the substrate

Regarding the globular structure of whey proteins, due to their properties and structures, they have been used as a vehicle for active substances such as antimicrobials, antioxidants and drugs, among others, for the development of new functional products [66–69]. This approach is widely used in several industrial sectors, providing the possibility of a controlled release of bioactive compounds. It can easily be applied to the textile industry, with the possibility to add functionality to textiles. The antioxidant effects of vitamin E encapsulated in BSA nanoparticles in cotton have already been studied [70]. The nanoparticles, produced by ultrasonic emulsification, have a size between 200 and 300 nm and have the capacity to encapsulate 99% of the vitamin. After impregnation onto cotton fabrics, they present an

Microspheres of BSA have also been tested as encapsulation agents of an antibiotic, tetracycline, in order to obtain an antibacterial coating for cotton and polyester fabrics [72]. These capsules demonstrated not only good encapsulation capacity but

Nonetheless, these types of applications at an industrial level have some limitations since the cost-effectiveness ratio of these biomacromolecules may not compensate until now. In addition, the durability to the laundering was not yet achieved in an effectively sustainable and long-lasting way, since these biomacromolecules have a waterborne character and these coatings come off from the textile when subjected to washing. When adding binding agents to biomacromolecules, a balance must be sought between their green characteristics and the use of chemicals that do not eradicate the sustainability of the process. In this sense, exploitation of biologically derived chemical treatments, or at least chemicals with a low environmental impact, which could make the proposed biomacromolecules more durable than they are today, while maintaining their effective functionalities, is being carried

**114**

out [73, 74].

a search for alternative solutions with the same performance of genuine leather, which catapulted textile industries towards sustainable innovation as a means of answering the markets' demands.

Vegetable leather is a sustainable product of plant origin resulting from the use of vegetable wastes or by-products. There are already some alternatives of vegetable leather on the market to replace animal leather, although they do not fully reproduce the characteristics of animal leather. Of the solutions on the market, the main examples are presented.

Latex-based leather is the name given to a fabric made up of two renewable raw materials, the latex extracted from the rubber tree (*Hevea brasiliensis*) from the Amazonian forests and cotton. The cotton is impregnated with latex, natural rubber (primary product of the smoking of latex extracted from the rubber tree). These can be used in the production of bags, wallets, clothing, footwear and other objects usually produced in leather. The commercialization of these products has become a reason for hope for the improvement of the life of rubber tappers, their permanence in the forest and the sustainable development of the Amazon, generating work and income in indigenous and traditional communities [78–80].

The company Ananas Anam has developed an innovative, natural and sustainable non-woven leather called Piñatex™, produced from pineapple leaf fibres, considered as a vegan alternative to traditional leather. From the pineapple leaf fibres, screens are obtained, which can be dyed, printed and treated to obtain different textures [81]. The material is strong, versatile (different colours, patterns, textures, thicknesses), breathable, smooth, light, flexible, sewable, resistant to water and abrasion and resistant to ignition by cigarettes [82–84].

Products based on thin sheets of cork, laminated with a textile substrate that gives it resistance, are increasingly being introduced to the market as a sustainable vegan alternative to traditional/synthetic leather. They have characteristics equivalent to leather, such as resistance, lightness, breathability, malleability, thermal insulation and impermeability, adding the properties of low density and thermal conductivity. There are several products based on cork leather (cork sheet) on the market, created and launched by designers/brands and national reference companies, such as Bleed—We bleed for nature, Pelcor, and Artelusa, and international, such as Chanel, inter Louboutin, Stella McCartney, Yves Saint Laurent, Prada, Dior, Manolo Blahnik, Dolce & Gabbana and Gucci. These products are based on fashion accessories (wallets, belts, etc.), clothing, umbrellas, footwear, sports goods, furniture, car upholstery lining, etc. [76, 85–90].

Wood-based leather is similar to cork but made from wood from fast-growing trees, such as oak bark, treated with non-toxic chemicals to make it durable, flexible and malleable. Wood leather can be as thick as genuine leather. Dolce & Gabbana is a market reference that has already used this material in a recent collection of bags and shoes [41]. The German shoe brand nat-2TM also recently launched a line of shoes in which up to 90% of the upper surface of the shoe is covered with wood, which is applied over an organic cotton, in order to become a flexible, soft material that allows to smell the wood and observe its natural texture [91]. Another solution is Wooden Textiles, created by Elisa Strozyk. These materials, which also bear some resemblance to leather, are obtained after cutting thin sheets of wood into pieces and adhering them to a textile substrate. The result is a material that smells like wood, but with some flexibility and softness. There are applications in decoration and furniture [92].

Vegea® is a biomaterial produced by the Italian company Vegea, founded by Gianpiero Tessitore and Francesco Merlino [86, 87]. This material, with a similar aspect to leather, valorizes residues from bagasse (skins and tales from grapes), and does not use water in its production [74]. This leather, also known as WineLeather,

is already available in several colors, and it can be used for studying or obtaining different thicknesses, strengths, finishes, and textures. It is already applied in the production of clothing, bags and shoes, furniture, packaging, and automobile and transport accessories [93]. It is used to coat a textile substrate with a polymeric mixture, consisting of a cake residue flour and a derived polymer of oil extracted from grapes [94].

The German company nat-2™ developed a material similar to leather, obtained from coffee bean wastes [95, 96]. With this material a line of unisex sneakers was created, whose upper part contains recycled coffee, coffee beans and coffee plant, which constitutes up to 50% of the footwear surface, according the model. The coffee is applied in a layer, giving a soft touch and a coffee aroma. Two Mexican inventors, Adrian Lopez and Marte Cazarez, recently created a laminate based on nopal cactus (or figs), which resembles animal leather, that is breathable, environmentally sustainable and totally plant-based (cotton and Nopal blend), lasts at least 10 years and has the chemical and physical properties required by the fashion industries, furniture, leather goods and automobiles [97, 98]. The material is obtained by coating a cotton substrate with a mixture of dry (in the sun) and crushed cactus powder and protein extracted from the cactus, which serves as a natural binder [99].

Another leather-like material example is bonded leather or reconstituted leather. This consists of the preparation of a paste with ground leather wastes and binding agents, which is extruded, using a process similar to the production of paper [100]. This paste can be applied on a textile support, coated with a PU film and embossed to gain a leather-like texture [101]. The colour and pattern are checked by a surface treatment. The amount of leather fibres in bonded leather can vary, which is reflected in the quality of the material. This product is usually used in furniture, bookbinding and fashion accessories. Depending on the quality of the product, it can be a durable material, with flame retardancy, and does not develop a patina. The number of patents on reconstituted or recycled leather is extensive, without, however, mentioning the use of textile support for the application of the paste with leather wastes [102–124].

RecycLeather™ is a green technology company that produces recycled materials with the look and feel of leather, highly durable, resistant and light. The materials are obtained from leather waste, in particular, cut pieces from gloves. It consists of 60% leather waste, 30% latex (a natural binder) and 10% synthetic products, such as water and pigments [125].

EcoDomo also has some collections with recycled leather [126]. This is obtained by pulverized leather fibres, obtaining materials with a leather content of up to 70%. It is available for different applications, such as furniture, panels, flooring, etc. EmbraceTM also has different materials, similar to leather, obtained from leather waste (43–58%), blended with cotton and polyester, and a PU topcoat [127].

Hydrolysed collagen has recently been applied in the leather manufacturing process, and in the production of flexible composite sheets, with polyvinylpyrrolidone (PVP) and cellulose derivatives, for application products in the area of footwear, clothing, etc. [128–130]. The application of collagen hydrolysates in leather production consisted of its mixture with oxazolidines before application, but the obtained results were not as good as those attained by tanning [45, 46]. The application of this by-product, without chromium separation, in the manufacture of flexible composite sheets with both PVP and cellulose allowed the obtaining of composites with improved mechanical properties (composites with PVP and cellulose) and greater thermal stability (cellulose composites) [47, 131].

Gelatex is a non-woven fabric (with nanofibres) made from gelatine derived from waste from the meat and leather industries, developed by Gelatex Technologies, a start-up from Estonia [132]. It is a material with a touch similar

**117**

*Innovation of Textiles through Natural By-Products and Wastes*

to leather and is breathable, durable and customizable (texture, thickness, water resistance, etc.). This material won the The Green Alley Award 2019 [133].

The mobilizing project TexBoost—less Commodities more Specialties is a structuring project of the Textile Cluster: Technology and Fashion, which aims to include a set of R&D initiatives with a strong collective character and high inductor and demonstrator effect, with the central involvement of companies of the textile and clothing sector, but also of other complementary sectors of the economy [134]. TexBoost consortium, led by RIOPELE and under the technical coordination of CITEVE, involves a total of 43 entities, of which 23 are industrial companies of the entire textile industry

The project is organized into six PPS—products, processes and services—of which it is worth highlighting the PPS5, sustainability and circular economy. This PPS5 aims the development of materials and solutions using wastes and by-products of other industries (footwear, automobile, cork, forest and milk industry) in new

For the first nuclear activity, vegan leather, the R&D work was focused in the development of a new generation of coated textile solutions that could be used as an alternative to natural and/or synthetic leather, using wastes and by-products of vegetable origin with new multifunctional properties combined with design and special fashion effects form the basis of this activity. The aim of this work were also to respond to one of the major trends in consumption, related to ethically and environmentally sustainable attitudes, developing products with a high potential for application in technical and functional areas, such as technofashion, eco-design, clothing, decoration, home textiles, footwear, fashion accessories, sport and protection, among others. During the project, several agro-industrial wastes were studied, and from them, eco-friendly and Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH)-compliant coating formulations were developed, and 100%

The mechanical performance of the developed solutions was assessed through a series of normalized tests, namely, Veslic friction resistance (ISO 11640: 2012), Martindale abrasion resistance (ISO 17704:2004), Crockmeter friction resistance (ISO 20433:2012), colour fastness (ISO 105-B02) and coating peeling (ISO 11644:2009) (N/cm). The obtained results are summarized in **Table 5**. In a general way, it is possible to conclude that the developed solutions pass the performance

Regarding the second nuclear activity—alternative leather solutions—the R&D activities focused on the development of a new generation of coated textile solutions by using wastes and by-products resulting from industrial operations, such as the tanning industry, natural leather cutting (for indoor automotive) and EVA (for shoe components), here highlighting the leather wastes, with new multifunctional properties combined with fashion design and special effects. The aim was also to meet one of the major trends of current consumption, which is related to ethically and environmentally sustainable behaviour, developing products with high potential for application in technical and functional areas and in rapid expansion: technofashion, eco-design, clothing, decoration, home textiles, footwear, fashion

During the project, leather waste was studied, eco-friendly and REACHcompliant coating formulations were developed, and 100% cotton textile substrates

and 15 are non-corporate entities of the research and innovation system.

cotton textile substrates were coated by knife coating (**Figure 1**).

*DOI: http://dx.doi.org/10.5772/intechopen.93011*

**5. Case of study**

and innovative textile solutions.

norms and specifications.

accessories, sport and protection, among others.

were coated by knife coating (**Figure 2**).

to leather and is breathable, durable and customizable (texture, thickness, water resistance, etc.). This material won the The Green Alley Award 2019 [133].
