**3.2 Agro-industrial wastes**

The passage of traditional industrial processes to more sustainable patterns and a circular economy model are mandatory given the limited resources and adverse environmental effects that are noticeable today. In this sense, the establishment of bio-based economies and industrial processes, such as the textile industry, will contribute directly to substitute emission-intensive and non-renewable resources with renewable resources, as well as create innovative and functional added-value solutions [9]. Some wastes or natural additives can provide a wide range of functional properties to textiles, opening an opportunity for the development of new and innovative textile solutions. Some potential functionalities of some vegetable and agroforestry wastes and by-products are presented in **Table 3**.

### **3.3 Leather wastes**

The manufacture of leather upholstery for furniture, airplanes and automobiles has been one of the main markets in the last two decades. Currently, in Europe, 14% of all new cars have leather coverings, and an additional 4% are made in combinations of leather, textiles, composite materials and imitation leather. The world's leading car manufacturers have focused on looking for renewable materials, recycling materials in manufacturing processes and using less toxic materials to improve car recyclability [43]. In the European footwear industry, the production of about 1–2 × 105 tonnes of leather waste per year is estimated, with the annual cost associated with its management between 4 and 10 × 106 € [44]. In the manufacture of footwear, more than 70% of the leather used is leather tanned with chromium [10].

Despite the many methodologies and systems studied and implemented in the last decades, which allowed the minimization of waste production during the manufacture of leather and its processing by user industries, such as the automotive and footwear industries, these production processes inevitably generate waste leather which can be disposed or valorized as it is or by chemical conversion into other added-value products (collagen) [10].


**111**

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

to their biodegradability, biocompatibility, etc. [15]. In addition, collagen and its derivatives have also another set of properties that enhance their potential, not only for the direct functionalization of textile substrates but also for the development of

**Functionality Description Ref.**

excellent foaming properties, even in the absence of gelling

bacterial membranes, acting as a natural fungicide and bactericide

Inhibition of lipid peroxidation, elimination of free radicals and acting as transition metal ion chelating agents, protecting cells from damage caused by oxidation and helping to improve skin firmness

[45–47]

Gelling and dilating Aggregation of molecules at 30°C to form hydrolysed collagen gels and gelatine; swelling in the presence of water

Foaming The presence of hydrophobic and hydrophilic amino acids provides

Antimicrobial Hydrophobic amino acids penetrate the peptide chains that make up

*Different functionalities of collagen and its derivatives and respective area of application.*

**4. Functional applications of natural by-products and wastes in the** 

The consumer demand for more environmentally responsible products with better sustainability credentials is increasingly growing, in addition to progressively more restrictive legislation regarding the environmental impact of industrial activity. Additionally, other increasingly important factors are the search for textile products with differentiated technical and functional properties and with better sustainability credentials, without compromising the appearance, touch, and

These facts have led companies in the textile and clothing sector to gradually invest in an investigation strategy that leads to the adoption of sustainable policies and reduction of environmental impacts, based on the valorization of wastes and by-products of industries that are geographically close. In this scenario, the reuse of these natural by-products and wastes as a bio-resource in the demanding textile

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

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

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

the coating formulations (**Table 4**) [15, 45, 46].

**textile industry**

Antioxidant/ anti-ageing

**Table 4.**

comfort of the article.

sector presents itself as an alternative.

**4.1 Textile fibres with whey protein**

stretching and enhance its physical properties [48, 51].

Native collagen and its derivatives are widely applied in the food, agrarian (fertilizer), cosmetic and biomedical industries, as well as in the textile industry, due

#### **Table 3.**

*Vegetable and agroforestry wastes and by-products and functionalities.*

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


**Table 4.**

*Waste in Textile and Leather Sectors*

**3.2 Agro-industrial wastes**

values [31–33].

**3.3 Leather wastes**

1–2 × 105

stabilizing effect on serum proteins, protecting them from denaturation at temperatures up to 90°C. Due to its structure, β-lactoglobulin can also form complexes with vitamins and nutraceuticals, such as folic acid. β-Lactoglobulin/folic acid complexes exhibit particle sizes below 10 nm and exhibit stability over a wide range of pH

The passage of traditional industrial processes to more sustainable patterns and a circular economy model are mandatory given the limited resources and adverse environmental effects that are noticeable today. In this sense, the establishment of bio-based economies and industrial processes, such as the textile industry, will contribute directly to substitute emission-intensive and non-renewable resources with renewable resources, as well as create innovative and functional added-value solutions [9]. Some wastes or natural additives can provide a wide range of functional properties to textiles, opening an opportunity for the development of new and innovative textile solutions. Some potential functionalities of some vegetable

The manufacture of leather upholstery for furniture, airplanes and automobiles has been one of the main markets in the last two decades. Currently, in Europe, 14% of all new cars have leather coverings, and an additional 4% are made in combinations of leather, textiles, composite materials and imitation leather. The world's leading car manufacturers have focused on looking for renewable materials, recycling materials in manufacturing processes and using less toxic materials to improve car recyclability [43]. In the European footwear industry, the production of about

tonnes of leather waste per year is estimated, with the annual cost associ-

footwear, more than 70% of the leather used is leather tanned with chromium [10]. Despite the many methodologies and systems studied and implemented in the last decades, which allowed the minimization of waste production during the manufacture of leather and its processing by user industries, such as the automotive and footwear industries, these production processes inevitably generate waste leather which can be disposed or valorized as it is or by chemical conversion into

Native collagen and its derivatives are widely applied in the food, agrarian (fertilizer), cosmetic and biomedical industries, as well as in the textile industry, due

**Waste/by-product Source Functionalities Ref.**

Rice husks Rice processing Thermal insulation potential [36]

Pine bark To feed Antioxidant, antimicrobial, aromatic [39, 40]

properties

€ [44]. In the manufacture of

Anti-odour, antimicrobial, aromatic;

Absorbent, mechanical and structural

Antimicrobial, aromatic [37, 38]

[34, 35]

[41, 42]

UV radiation protection

and agroforestry wastes and by-products are presented in **Table 3**.

ated with its management between 4 and 10 × 106

other added-value products (collagen) [10].

Coffee grounds Coffee production

Eucalyptus bark Wood processing

Pine sawdust, composite sawdust, powder and pieces process

industry

*Vegetable and agroforestry wastes and by-products and functionalities.*

Wood processing industry

**110**

**Table 3.**

*Different functionalities of collagen and its derivatives and respective area of application.*

to their biodegradability, biocompatibility, etc. [15]. In addition, collagen and its derivatives have also another set of properties that enhance their potential, not only for the direct functionalization of textile substrates but also for the development of the coating formulations (**Table 4**) [15, 45, 46].
