Natural and man-made textiles

Comparative life cycle assessment of natural and man-made textiles... 

The second and third types of fibres, regenerated and synflietic, are commonly grouped as man-made fibres. Hence, this chapter focuses on a comparative look at these natural and man-made textiles with an LCA lens. The detailed aspects of production processes, pertinent environmental impacts, etc. have already been reviewed and presented by the author in a previous book (Muthu, 2014). 

There are a limited number of studies in the literature that have compared man-made and natural textiles in the same study under similar conditions. Of course, there is a great deal of available information from the Internet and also from several consultancy studies/research papers that provide comparative figures of natural and man-made textiles. This kind of information on the environmental impact of various textile fibres, processes and technologies under natural and man-made categories of textiles have already been thoroughly reviewed and discussed in the author s previous book (Muthu, 2014). Hence, the same information is not repeated in this chapter this chapter is concerned with studies that have directly compared both natural and man-made textiles under similar conditions/system. 

Unfortunately, there are scant LCA studies on many textile products or product categories and again, there is a dearth of such comparative LCA studies on textiles. There are only a few textile studies that have compared both natural and man-made textiles on a single platform and measured different environmental indicators. The very tiny number of smdies available in the literature were referred to and discussed in this chapter. 

Functional fibres, filaments and yams are the basic building blocks of electrotextiles. The textile industry has demonstrated a remarkable capability to incorporate both natural and man-made filaments into yarns and fabrics to satisfy a wide range of physical parameters which survive the manufacturing process and are tailored to specific application environments. Electronic components can be fabricated within and/or on the surface of filaments and can subsequently be processed into functional yams and woven into fabrics. Passive components such as resistors, capacitors and inductors can be fabricated in several different manners. Diodes and transistors can be made on long, thin, flat strands of silicon or formed in a coaxial way. Progress has been made in the development of fibre batteries and fibre-based solar cells. In addition, a variety of actuated materials (piezoelectric, etc.) can be made into multiple long strands (filaments) and subsequently be woven into fabric. 

Usage in the preparation, dyeing and finishing of textiles of natural and man-made fibers as well as synthetics and their blends. 

With the industrial revolution came new discoveries and the development of the manufactured fibers industry, which was able to produce more new fibers than could be obtained from nature. The use of medical textiles derived from natural and man-made fibers as drug carriers increased dramatically, mainly in the form of bandages, therapeutic textiles, healthcare textiles, wound dressings, surgical operative sutures, transdermal patches for dermatosis and also for specific diseases. 

Textile fibers are normally broken down into two main classes, natural and man-made fibers. All fibers which come from natural sources (animals, plants, etc.) and do not require fiber formation or reformation are classed as natural fibers. Natural fibers include the protein fibers such as wool and silk, the cellulose fibers such as cotton and linen, and the mineral fiber asbestos. Man-made fibers are fibers in which either the basic chemical units have been formed by chemical synthesis followed by fiber formation or the polymers from natural sources have been dissolved and regenerated after passage through a spinneret to form fibers. Those fibers made by chemical synthesis are often called synthetic fibers, while fibers regenerated from natural polymer sources are called regenerated fibers or natural polymer fibers. In other words, all synthetic fibers and regener-... 

Raw materials for the manufacture of textile products are fibers, both natural and man-made. The choice of material-natural or man-made fibers or even blends-depends on the field of application and the desired properties of the product. 

Often used nowadays in the sense of textile material, e.g., natural fibre, man-made fibre, but correctly it refers to the comparatively short thread (staple fibre) of natural textiles. A fibre is fine, flexible, and very long in relation to its thickness. 

It is a long-standing dilemma in textiles when trying to conclude which one is better for the environment — a natural textile product or a man-made textile product The industiy is full of myths and general perceptions, which may or may not be trae. As mentioned in one of the previous books, a scientific LCA study conducted with aU the above-mentioned elements consistently is the way to find out the answer... 

Nonwovens are textile products that are manufactured directly from fibers. They are defined as a manufactured sheet, web, or matt of directionally or randomly oriented fibers, bonded by frictiOTi, and/or cohesion, and/or adhesion excluding paper and products which are woven, tufted, stitch-bonded incorporating binding yams or filaments, or felted by wet milling whether or not needed. The fibers may be of natural or man-made origin. They may be staple or continuous filaments or maybe formed in situ [37]. 

The word "textile" was originally used to define a woven fabric and the processes involved in weaving. Over the years the term has taken on broad connotations, including the following (1) staple filaments and fibers for use in yarns or preparation of woven, knitted, tufted or non-woven fabrics, (2) yarns made from natural or man-made fibers, (3) fabrics and other products made from fibers or from yarns, and (4) apparel or other articles fabricated from the above which retain the flexibility and drape of the original fabrics. This broad definition will generally cover all of the products produced by the textile industry intended for intermediate structures or final products. 

Figure 1.2. Classification of fibers. This is different from the commonly used classification of textile fibers. In the textile fiber classification, fibers are divided into natural fibers and man-made fibers.

Chemicals are ubiquitous as air, carbohydrates, enzymes, lipids, minerals, proteins, vitamins, water, and wood. Naturally occurring chemicals are supplemented by man-made substances. There are about 70000 chemicals in use with another 500-1000 added each year. Their properties have been harnessed to enhance the quality of life, e.g. cosmetics, detergents, energy fuels, explosives, fertilizers, foods and drinks, glass, metals, paints, paper, pesticides, pharmaceuticals, plastics, rubber, solvents, textiles thus chemicals are found in virtually all workplaces. Besides the benefits, chemicals also pose dangers to man and the environment. For example ... 

This textile fiber is the first man-made organic textile fiber prepared wholly from new material from the mineral kingdom. Though wholly fabricated from such common raw material as coal, water, and air, nylon can be fashioned into filaments as strong as steel, as fine as spider s web, yet more elastic than any of the common natural fibers. 

Until the 20th century mankind was limited to natural fibers such as wool, cotton, linen, and for the rich, silk. The first man-made fiber was artificial silk rayon (1910), which was based on cellulose. The big jump came with the invention of nylon by Wallace Carothers, with commercial production starting in 1939, followed in the 1950s by acrylics (which, when mixed with cotton, produced the wash-and wear textiles), polyesters, and many others. 

Up to the present time conservators were interested in preserving textiles made from natural fibers. With time, however, as present day materials incorporating man-made fibers are collected, concerns will arise as to their preservation and display. In this chapter, I survey the different types of man-made fibers, discuss environmental factors that can degrade them, and indicate methods for the identification or estimation of such damage. Also, I indicate where precautions need to be taken in their cleaning and display. 

The preservation of textiles made from man-made fibers requires attention to similar factors as textiles made from natural fibers—i.e., temperature, humidity, light conditions, and air purity. In some instances, preservation should be easier. Synthetic fibers and cellulose derivative fibers, for example, would be less prone to insect damage than natural fibers. As in the case of the natural fibers, there are well-established techniques for determining the type and extent of damage that has occurred to man-made fibers during use. This will assist in determining cleaning and preservation techniques. 

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