328 16.From Natural Fibers to Man-Made Plastics all natural fibers and its production is cumbersome,as will be described later.Chinese silk textiles manufactured during the Han dynasty (206 B.C.-A.D.220)have been found in Egypt,in graves located in northern Mongolia,and in Chinese Turkistan. During the years of the industrial revolution,that is,in the eighteenth and nineteenth centuries,a number of machines were invented and put into service which transferred spinning,weav- ing,and other fiber-processing techniques from individual homes to centralized factories with consequential economic hardships for some people and concomitant social upheavals.These ma- chines which produced relatively inexpensive fabrics triggered, however,an increase in fiber demand and production. In the 1880s,it was eventually learned how to dissolve cellu- lose (from soft wood)and to extrude the resulting substance through narrow nozzles to form regenerated cellulose fibers such as artificial silk,which was later called viscose or rayon (see Section 16.3).Actually,the first artificial silk is said to have been made in 1879 by J.W.Swan in England for filaments of light bulbs even before Edison came up with his version!The first rayon stockings for women were manufactured as early as 1910 in Germany.(In France,viscose was called "mother-in-law silk"because of its extremely high flammability.)From there it was only one more (but not so easy)step to create completely synthetic fibers(from coal or oil)such as nylon.2 These new prod- ucts challenged the monopoly of natural fibers for textile and in- dustrial uses.Still,even today,more than one-half of the world's fibers stem from natural sources,among which cotton consti- tutes the most important part (Figure 16.1).We shall return to these topics in Sections 16.3 and 16.4. Natural fibers are generally classified by their origin.The plant or vegetable fibers are mostly cellulose-based,that is,they con- sist of polymers derived from carbohydrates (i.e.,CnH2nOn) which are manufactured by the plant from water and carbon dioxide gas through photosynthesis.They include bast fibers from stems of plants (jute,flax,sunn,hemp,ramie),leaf fibers (sisal, New Zealand flax,henequen,abaca,istle),palm-type and brush fibers (coir,raffia,palmyra,piassava),seed and fruit-hair fibers (cotton,kapok),and,of course,wood from trees.Table 16.1 con- tains usage,price,and origin of some of these fibers. Among the animal fibers,which are protein-based,are wool, mostly from sheep.Specialty animal fibers include mohair from Actually,the first useful light bulb was invented by the German H. Goebel who,in 1854,inserted a carbonized bamboo fiber into an evac- uated glass flask exactly like Edison 25 years later. 2Generic name for polyamides.all natural fibers and its production is cumbersome, as will be described later. Chinese silk textiles manufactured during the Han dynasty (206 B.C.–A.D. 220) have been found in Egypt, in graves located in northern Mongolia, and in Chinese Turkistan. During the years of the industrial revolution, that is, in the eighteenth and nineteenth centuries, a number of machines were invented and put into service which transferred spinning, weav￾ing, and other fiber-processing techniques from individual homes to centralized factories with consequential economic hardships for some people and concomitant social upheavals. These ma￾chines which produced relatively inexpensive fabrics triggered, however, an increase in fiber demand and production. In the 1880s, it was eventually learned how to dissolve cellu￾lose (from soft wood) and to extrude the resulting substance through narrow nozzles to form regenerated cellulose fibers such as artificial silk, which was later called viscose or rayon (see Section 16.3). Actually, the first artificial silk is said to have been made in 1879 by J.W. Swan in England for filaments of light bulbs even before Edison came up with his version!1 The first rayon stockings for women were manufactured as early as 1910 in Germany. (In France, viscose was called “mother-in-law silk” because of its extremely high flammability.) From there it was only one more (but not so easy) step to create completely synthetic fibers (from coal or oil) such as nylon. 2 These new prod￾ucts challenged the monopoly of natural fibers for textile and in￾dustrial uses. Still, even today, more than one-half of the world’s fibers stem from natural sources, among which cotton consti￾tutes the most important part (Figure 16.1). We shall return to these topics in Sections 16.3 and 16.4. Natural fibers are generally classified by their origin. The plant or vegetable fibers are mostly cellulose-based, that is, they con￾sist of polymers derived from carbohydrates (i.e., CnH2nOn) which are manufactured by the plant from water and carbon dioxide gas through photosynthesis. They include bast fibers from stems of plants (jute, flax, sunn, hemp, ramie), leaf fibers (sisal, New Zealand flax, henequen, abaca, istle), palm-type and brush fibers (coir, raffia, palmyra, piassava), seed and fruit-hair fibers (cotton, kapok), and, of course, wood from trees. Table 16.1 con￾tains usage, price, and origin of some of these fibers. Among the animal fibers, which are protein-based, are wool, mostly from sheep. Specialty animal fibers include mohair from 328 16 • From Natural Fibers to Man-Made Plastics 1Actually, the first useful light bulb was invented by the German H. Goebel who, in 1854, inserted a carbonized bamboo fiber into an evac￾uated glass flask exactly like Edison 25 years later. 2Generic name for polyamides