Editor’s note: Reprinted, with changes, from “Introduction To Nonwovens Technology,” by Subhash
							K. Batra, Ph.D., and Behnam Pourdeyhimi, Ph.D., (Lancaster, Pa.: DEStech Publications Inc., 2012),
							xvii-xxix, by permission of the authors and publisher. 
 With the exception of wool felts, fabric making has historically involved the conversion of
							fibers into yarns and yarns into fabrics, primarily by weaving, knitting or lace making. The beauty
							of these technologies lies in their ability to assemble thousands, indeed millions, of individual
							fibers — themselves weak, difficult to handle and sometimes functionally useless — into integrated
							products that are strong, foldable, absorbent, soft, and permeable. Most fascinating, the fabric is
							often held together, in a highly ordered structural fashion, by frictional forces only. As such,
							the woven, knit and lace fabrics on the one hand, and wool felts on the other, take the old dictum
							“there is strength in numbers” a significant step further: “there is even more strength in ordered
							numbers.” 
 Many of the physical/mechanical properties of woven, knit and lace fabrics are derived from
							their unique hierarchy of structure: fiber, yarn (single or plied), and fabric. The history of the
							fiber-based-product industry is replete with examples of proper selection of fibers, yarn structure
							and fabric structure, followed by suitable after-treatments (dyeing, printing, finishing), leading
							to unique combinations of characteristics such as strength, flexibility, draping, controlled
							dimensional stability, and aesthetics in the final product. 
							 
							A coated nonwoven substrate of fibrillated islands-in-the-sea fibers is the material used
							in this full-sized tent for military operations.
							
 
 During the late nineteenth and early twentieth centuries three economic necessities led to
							the development of the precursors of various fabric making technologies that gained momentum during
							the latter half of the twentieth century. The three necessities and the response to them may be
							summarized as follows: 
- The need to reclaim acceptable quality fiber from clothing, scraps and other textiles,
 particularly those made from wool, and reuse it to make economically competitive clothing and other
 articles. This led to the development of fiber reprocessing machinery and a new industry dependent
 upon it.
- The need to convert coarse hair not suitable for yarn making or felting, and coarse fibers of
 vegetable origin, into economically viable products. This led to the development of the needle loom
 to accomplish fiber entanglement by barbed needle punching (bonding).
- The need to profitably utilize fiber waste, or fibers not suitable for yarn spinning, such as
 wood pulp, from the emerging manufactured- fibers industry. This led to the idea of converting
 fibers into fiberwebs, and then using adhesives or other means to give webs integrity to function
 as fabrics.
 1,2
 In time, these three developments, in conjunction with many others, led to the revolutionary
							idea that commercially acceptable, textile-like sheet structures could be made without first
							converting fibers into yarns. That this could be done without weaving, knitting or lace making was
							even more revolutionary. 
 Woodings
							3 states “Heavyweight needlepunched ‘felts’ made from jute and sisal have been made
							since the 1890s in both the UK and USA.” The earliest product using fiberwebs for commercial
							purposes may well be the one embodied in a patent, USP 0,123,136, which was granted, in 1872, to
							Milton D. Whipple, who stated: 
 What I claim, and desire to secure by Letters Patent, is –
							
- The series of needles or pins, slightly roughened or barbed, set in a suitable frame or holder,
 and made to traverse back and forth through a bat or web of cotton or other fibrous substance, for
 the purpose of interlacing and condensing the fibers, substantially as herein described.
- I also claim, as a new article of manufactre, a bat, web, or sheet made as hereinbefore
 described.
– Milton D. Whipple. 
 The seeds of the nonwovens industry may thus have been sown in the 1870s. The germination,
							however, only began in earnest in the United States and in Europe during the 1920s,
							4 1930s,
							5 and 1940s.
							6 The industry finally became commercially viable in the United States and in Europe
							during the 1970s, and a bit later in Japan and elsewhere. Since then the growth of the industry and
							the versatility of its products has been revolutionary, even chaotic – albeit a healthy one,
							manifest in the problem of defining the nature of the products
							(See Chapter 1: Definitions). 
							 

							The Winged Fiber™, measuring 15 by 10 microns in the illustration, top, is shown in a cross
							section of a nonwoven fabric, bottom.
							
							
							
 
							Nonwovens Forerunners
							
							
 The concept of “nonwovens,” as fibers in a network or web form, is not new. But to trace the
							origins of the concept poses a challenging problem.
							7
 First, there are the forerunners we find in nature: the nests of many birds, mammals, and
							invertebrates; the spunbond-like cocoon produced by the silk worm; spider webs; the root structures
							of trees, shrubs and grasses, which serve as natural erosion control akin to modern geotextiles;
							the fibrous skeletal structure of bark and leaf components of shrubs and trees; the extremely fine,
							spunbond-like fibrous structure of the every day egg-shell; the paper-like hornet nest. 
 Second, according to a reference in Wikipedia, the art of felt making from wool was
							developed by the early Sumerians around the fourth millennium B.C., just as the ancient Egyptians
							were devising fibrous network structures from papyrus.
							8 Beaten bark-cloth made from the inner bark of trees of the mulberry family — paper
							mulberry, bread fruit, wild fig — has been in use in Oceania, Africa, Southeast Asia, and the
							Americas from prehistoric times. Several layers of this cloth can be bonded together by moisture
							and beating, which presumably release the inner resins
							9 that provide the binding material. 
 Third, according to Gordon: “There are several similar recurring legends about the discovery
							of felt. In one, Noah attempted to make his ark more comfortable by padding the floor with sheep’s
							wool. By the time the journey of forty days and nights had passed, the loose wool had turned to a
							matted fabric (felt) by the pressure and moisture the animals had subjected it to.” The author
							cites further examples: “Another legend placed the discovery in France in the Middle Ages. A monk
							who lived in the city of Caen decided to make a pilgrimage to a distant shrine. He set out wearing
							a pair of new sandals and his feet soon became sore and tired. To make them more comfortable, he
							picked some wool from the backs of the sheep and put it in his sandals. When he arrived at his
							destination after fifteen days of walking, he found a strong soft cloth had been created by the
							constant moisture and pressure of his feet … An almost identical story takes place in the Middle
							East, where a tired, foot-sore camel driver took some of the soft hair from his camels and put it
							in his sandals. By the time the caravan reached its destination, he, too, had discovered felt …
							it is generally believed that it was the nomadic people of Central Asia who first learned to make
							it … The oldest pieces of fabric to have been found date from about 1500-1000 B.C. Felt caps as
							old as 3,500 years have been found in Scandinavia, and several items from the later Bronze Age
							(1400-1200 B.C.) have been found in tombs in northern Germany and Siberia.” 
 Fourth, Ruiji and Ke’an
							10 speculate that the invention of paper, which is in some sense a nonwoven, “during the
							early Western Han Dynasty (206 B.C.-8 A.D.) was most probably introduced from silk floss making. To
							make the silk floss, the ‘waste’ cocoons were beaten on a bamboo screen in water. After thorough
							beating, there was a layer of silk fiberweb left on the screen. This web-form material might have
							been culled and used as paper …” They also suggest that, according to recent archaeological
							evidence, paper made from hemp was introduced in China as early as the second century B.C. More
							reliable records in Han Shu (The History of the Han Dynasty) state that Cai Lun made great
							improvements in paper making in 105 A.D. Other sources assert that Ts’ai Lun first introduced
							paper: it could be made from “bark, hemp, fish net and rags.”
							11 The art of Washi, paper making by hand, using hemp and fibers from mulberry or
							certain deciduous trees, dates back to the sixth century A.D. in Japan.
							12
 Fifth, if a silk worm, ready to spin, drops to the floor, it will not stop spinning: the
							result is a “flat cocoon,” or “cocoon paper,” akin to modern day spunbond web. The ancient Chinese
							knew this. According to Ruiji and Ke’an, the earliest records of the technologic utilization of
							this phenomenon date back to the Song Dynasty (960-1279 A.D.). 
 Sixth, the industrial process of papermaking was based on adaptation of a machine invented
							by Nicholas-Louis Robert in 1798. “In 1801, Robert and his brother-in-law John Gamble patented the
							machine in England. They divided the patent rights with their financial backers, Henry and Sealy
							Fourdrinier.”
							13 Similarly, as Gordon tells, the industrial process of wool-felt making was invented
							by an American, named J. R. Williams, in 1820. 
 Seventh, Millman
							14 suggests the invention of nonwovens can be traced to a British Letters Patent Number
							114, granted in 1853 to Bellford, which detailed the use of carding machines, conveyor belting,
							impregnating, mattresses, and cushions. 
 Eighth, Tyas
							15 claims that the production of needle looms was established around 1870 by William
							Bywater Ltd.; whereas Ward
							16 asserts that “one of the first, if not the first, needle loom was built by …
							Bywater … in 1878 and delivered to a Leeds woolen manufacturer, Hargreave & Mussey, for
							making horse blankets.” Some put the date as early as 1860 and the location as both England and
							Germany. It is interesting to note that an air-based entangling predecessor to the current
							water-based entangling systems dates back to 1882.
							17 Claim 2 of the patent states: “The herein-described method of making a fur bat in a
							continuous flat sheet – that is to say, by depositing a layer of loose fur upon a traveling fabric
							of substantially non-feltable fibrous material and attaching the fur to the fabric by means of an
							air-current which passes through the fur and the fibrous material, substantially as set forth.” 
							Industry Development
							
							
 Thus, while the antecedents of nonwovens technology and products can be traced to various
							points in human history, most writers tend to place the beginning of the industry, as we know it
							today, to the late 1920s or early 1930s. Nottebohm
							18 cites a German patent, DRP Nr. 544324, dated August 26, 1928, which claimed the
							production of a fleece in combination with a glued web to serve as a shoe reinforcing material:
							KALFF Vliesstoffe GmbH is still in business today. Nottebohm also cites a Dutch Blaupotten Cate
							process disclosure in 1930 for the manufacture of artificial leather backing from fiber fleece to
							be glued with natural rubber. The earliest patent cited by Buresh
							19 is dated March 12, 1929, or April 29, 1930, depending upon one’s interpretation of
							their specific relevance to nonwovens technology. 
 According to Hays,
							20 laboratory and pilot scale production of non- wovens started in the 1930s. Shearer
							21 and Millman put the industrial production of “bonded-fiber nonwoven fabrics” in
							commercial quantities (a few thousand pounds) around 1942. George M. Schroder, at the University of
							Chattanooga, created the first disposable diaper using nonwoven fabric in 1947.
							22 In 1948, Freudenberg introduced dry-laid resin bonded fabric for interlining. 
 The latter part of the twentieth century spawned several commercially viable new
							technologies to make fabrics that could compete with wovens, knits and lace. Most of these have
							been grouped under the umbrella of nonwovens technology. Today the nonwoven roll goods and related
							industries yield highly engineered products for such applications as filters, diaper and sanitary
							napkin cover-stock, tear resistant envelopes, needled carpets, wipes, medical use, protective
							clothing, interlining in apparel, agricultural use, insulators for space shuttle heat shield,
							furniture components, high loft products, and on and on. 
 Traditionally, the nonwoven industry (10-100 m/min; $10-$100 MM) has been compared to
							weaving (1-2 m/min; $10-100 MM), knitting (2-5 m/min; $1-50 MM) and paper industry (100-1000 m/min;
							$50-100 MM) in terms of line speeds or typical plant costs. While line speed comparisons make
							nonwovens look impressive, they are meaningless; for it is the unit cost of production of a
							comparable product that makes the difference in its competitive edge in the market place. The plant
							costs give some idea of the capital required – a possible barrier to entry – to get into the
							business. But far more important is to assess the performance versus the cost needed to develop the
							market and to distribute the product reliably. 
 The success and growth of the nonwovens industry is due, in large measure, to expanding
							markets which encourage continued developments in process technologies, raw materials and final
							product design to meet the existing as well as future challenges in product performance at an
							acceptable cost. In other words, the raw materials available, the technologies available, and the
							creative abilities of the product designers can optimize the performance specifications required in
							the final product at an acceptable cost to the consumer. Table 1, which is by no means exhaustive,
							lists typical properties identified by EDANA, some of which must be met by a successful product at
							an optimal performance level and price. 
							Properties Of Nonwovens
							
							
							
							Source: EDANA
							
							
							
 The nonwovens industry in 2008 produced 5.78 million tonnes of roll goods worth US $21.2
							billion (and a growth rate in excess of 8%), comprising 28.6% in Europe, 25% in North America,
							19.7% PRC, 10% in other Asia Pacific regions. These roll goods were used in numerous applications
							as illustrated by Tables 2 and 3. Table 2 presents the segmentation of end use markets classified
							by EDANA, a trade organization in Europe, while Table 3 does the same for INDA, the nonwovens
							industry trade organization in the United States. Neither is exhaustive, but they illustrate the
							different ways end use markets can be classified based on the judgment of individuals or companies.
							End Use Classification By EDANA (2004)
							
							
							
							Source: EDANA
							
							
							
							End Use Classification By INDA (2004)
							
							
							
							Source: INDA
							
							
							
 The nonwovens industry is organized differently and separately from the textile industry.
							While both, along with the paper industry, share some common heritage, the nonwoven industry during
							its evolution has integrated high-speed, low-cost, innovative, value-adding processes to produce a
							broad array of engineered fiber and polymer based products. In doing so, it has adapted
							technologies from the pulp and paper industry, the fiber/polymer extrusion industry, and the
							traditional textile industry. The traditional textile industry is intimately linked to the apparel
							and home furnishing industries. The nonwovens industry is not. 
 Depending on the local/regional markets and their economic constraints, segments of the
							nonwovens industry today include raw material suppliers, roll goods producers,
							converters/fabricators of end use products, supportive machinery industry, and auxiliary material
							suppliers. 
							Portfolio Of Technologies
							
							
 Finally, a few words about the framework for our study of nonwovens technology and the
							characteristics of the products made from them. “Nonwovens Technology” is in fact a portfolio of
							technologies. The available fiber, or polymer raw materials to be processed, have critically
							influenced the development of the technologies. At the same time, the technologies available to
							process them have equally influenced the development of new fibers and polymer raw materials. The
							rich portfolio of technologies under consideration offers numerous options for processing paths to
							attain desired end-product characteristics. There is, thus, no unique systematic, linear way to
							teach or learn the technology and its products. To that extent, this book departs from what has
							become a traditional path. The paradigm used here might be likened to an impressionistic painting:
							up close it consists of bold brush strokes or dabs of different colors, which may or may not be
							very pleasing by themselves, nor represent any recognizable form; but, seen from a distance, the
							mind of the observer integrates them into a pleasing or provocative picture. 
 This first volume of the book is divided into five parts. Part I deals with some useful
							preliminaries, such as the issue of definitions of the structures of interest, the concept of
							structure and its description in the case of two dimensional fiberwebs, the distinction between
							technology as it refers to a sub-process, and
							Technology as it refers to the whole raw-material-preparation-to-roll-good system. 
 Part II deals with the preparation and web formation steps for staple fiber-based
							Technologies, including opening, blending, carding and airlay processes for both
							conventional fibers as well as pulp-focused. This prepares the ground for discussion of the broad
							spectrum of bonding processes in Part III. These include needle punching, hydroentanglement,
							thermal bonding (inclusive of ultrasonic bonding) and resin bonding. To give some depth to thermal
							bonding, some relevant concepts of heat and heat transfer are reviewed briefly in a stand-alone
							chapter. 
 In Part IV we introduce the (historically) integrated
							Technologies, such as wetlay, spunbond and meltblown; the latter two involve polymer melt
							extrusion. To make the spunbond, meltblown processes more intelligible, a stand-alone chapter
							reviews some relevant concepts of polymer physics. The latter also supports the subsequent
							discussion on split-film nonwovens and nano or near-nano scale webs obtained via flash spinning,
							electrospinning and those obtained via bicomponent fibers. 
 In Part V we discuss processes and the idea of integration to produce heterogeneous
							fiberwebs (second order structures, composites) and hybrid (higher order) structures, which combine
							more than one level of structure to yield structures with enhanced performance attributes. Some of
							the processes are those introduced previously, while others such as stitchbonding, co-forming, and
							NAPCO technology are introduced for the first time. 
 The book’s aim is to provide a structured path for teaching the subject matter to
							undergraduate as well as graduate students. That requires the instructors to selectively define
							suitable paths for the two levels. 
 The structure of the book is also designed to assist self-learning by industrial
							practitioners at different levels of experience and preparation. We hope it will deepen their
							appreciation of the diverse technologies available to them and stimulate the flow of their creative
							juices to design and produce products that benefit humankind. 
 Finally, we end with an appeal to teachers, students and other readers to send us any
							comments and suggestions that will improve our textbook and help make it a truly useful one. Please
							make up your own problems and exercises and share them with us. For such contributions and others,
							we thank you in advance. 
 In anticipation,
							
 Subhash K. Batra
							
 (subhash_batra@ncsu.edu)
							
 Behnam Pourdeyhimi
							
 (behnam_pourdeyhimi@ncsu.edu) 
							Subhash K. Batra, Ph.D., is Charles A. Cannon Professor, Emeritus; and Director Emeritus,
							Nonwovens Cooperative Research Center, North Carolina State University (NCSU).
 Behnam Pourdeyhimi, Ph.D., is William A. Klopman Distinguished Professor; and Director,
							Nonwovens Institute, NCSU. 
Footnotes (Endnotes in this case):
							
1USP 2,825,389.
							
2Subsequently, the manufactured-fiber industry fueled the growth of the nonwoven roll
							goods and related industries.
							
3Regenerated Cellulose Fibers, Edited by Calvin Woodings, CRC Press, 2000, Woodhead
							Publishing, 2001.
							
4Joseph, Gatti, Wadding and bat; USP 1,695,805 (1928).
							
5N. H. Brewster, Sheet material and method of making the same , USP 1,978,620.
							
6Batra, S. K., S. P. Hersh, R. L. Barker, D. R. Buchanan, B. S. Gupta, T. W. George and
							M. H. Mohamed, “Neither Woven Nor Knit: A New System for Classifying Textiles,” in
							Principles of Nonwovens, INDA , Cary NC (1992).
							
7See the previous reference.
							
8http://www.mnsu.edu/emuseum/prehistory/egypt/dailylife/papyrus.html.
							
9Gordon, Beverly,
							Feltmaking, Watson-Guptill Publications, New York (1980).
							
10Ruiji, Yang and Ke’an, Sheng, “The History and Prospect of Nonwovens in China,”
							Journal of East China Institute of Textile Science and Technology, No. 1, 27-34 (1984).
							
11Langer, William L.,
							An Encyclopedia of World History, Houghton & Mifflin Co., Boston (1952).
							
12Koda, M., “Washi,” in
							Tajyo, special edition, Shikosha Publishing Co., Japan (1982).
							
13http://historywired.si.edu/detail.cfm?ID=397.
							
14Millman, George E., “The Expanding Market for Nonwovens,”
							American Dyestuff Reporter, 58/7, 32-39, April (1969).
							
15Tyas, T., “The Design of Needle Looms,” in
							Needle-Felted Fabrics, ed. P. Lennox-Kerr, The Textile Trade Press, Manchester, UK.
							(1972).
							
16Ward, D., “A Hundred Years of Needle Looms,” in
							Nonwovens Yearbook, Nonwovens Report International (1979).
							
17US Patent 253,162 (1882).
							
18Nottebohm, C. L., “Vliesstoffe auf trockenem Weg,”
							Chemiefasern 9, 667-676 (1968).
							
19Buresh, Francis M., Nonwoven Fabrics, Reinhold Publishing Corporation, New York
							(1962).
							
20Anonymous, “Nonwovens-Threat or Opportunity,”
							American Dyestuff Reporter, 58/7, 40-41, April (1969).
							
21Shearer, Howard E., “Methods of Producing Bonded-Fiber Fabrics,”
							American Dyestuff Reporter, 41, P874-P879, December 22 (1952).
							
22http://www.disposablediaper.net/content.asp?2.
May/June 2012