Thursday, August 27, 2009

WEAVING TODAY

Weaving Today

Today most of our textile needs are supplied by commercially woven cloth. A large and complex cloth making industry uses automated machines to produce our textiles.

However, there are artisans making cloth on hand looms, in home studios or small weaving businesses, who keep alive the skills and traditions of the early weavers.

Foot-treadle Loom or Floor Loom

The foot-treadle loom came about after many years of development and exploration. This loom employed a pulley and lever system and the slot-and-eye heddle system giving a clear shed and freeing up the weaver's hands. Generally, weavers today prefer floor looms containing foot treadles, which can rise and lower warp threads at will. With the creation of the floor loom, the shuttle carrying the weft threads could now be passed back and forth across the warp without interruption.

Backstrap Loom

Eventually the backstrap loom was developed, and not only was it easy to transport, it was simple to construct. One end of the loom was attached to a fixed point, like a tree trunk, and the other was attached to a rod, which was held in place with a cord that passed around the waist of the weaver. By leaning back against the waist cord, the weaver could put tension on the warp threads and adjust tautness at will. Click here to view a diagram of a backstrap loom.

Not only could the loom have shed sticks, it could also be fashioned with the slot-and-eye heddle system, a significant step in loom evolution. This tool not only gives two clear sheds, it also acts as the beater, pushing weft threads into place. Clearly, the heddle system was used on looms types other than the backstrap, but once again, we have no way of knowing exactly when this tool was used for the first time.

The backstrap loom is still used today by Native Americans in the southwestern part of the United States and by people in Central America and Mexico. The loom is limited in complexity only by the skill of the weaver, and the entire loom with the weaving in progress can be rolled up at any time and carried from place to place.

Frame Loom

With the development of the frame loom, the weaver was had a portable tool, one that was easily constructed and could be used almost anywhere. The loom was built using four sticks, attached at right angles, making it necessary for opposite sides to be equal lengths. The warp was wound by tying a warp thread to the top stick and moving down to the bottom stick, wrapping around it, and moving back to the top, and repeating this process until the desired width was achieved. The weaving could be done by holding the loom in one's lap or by placing the loom on a table. A shed stick could be installed to lift warps as needed. Click here to view a twentieth-century example of a frame loom.

Pit Loom

Since the horizontal ground loom required the weaver to lean over to accomplish his task, this made for a very uncomfortable exercise. Eventually, the ground loom evolved into the pit loom, so named because the loom was placed over a pit which was dug into the ground. The weaver could now sit comfortably on the edge of the pit with legs dangling in the hole and be on the same plane as the loom. Click here to view a drawing of a pit loom.

Horizontal Ground Loom

The horizontal ground loom, probably a spin-off of the warp-weighted loom, was another primitive weaving tool. Equally spaced sticks or pegs were driven fairly deep into the ground in two parallel lines. The lines were spaced several feet apart, depending upon the desired length of the fabric to be made. The distance between the pegs varied according to the type of weaving desired, and the width of the two rows also played a part in the size of the fabric. Winding the warp began by tying the warp yarn onto the outside peg in one row and then crossing over to and wrapping around the corresponding peg in the opposite row, and then back to row one, peg two, and so on. Constant tension in winding the warp was imperative for a successful weaving. Using a shed stick and one or more shuttles, the weaver would bend over the tensioned warp and weave from the one end to the other.

Warp-weighted Loom

It is thought that the first looms, called warp-weighted looms, were vertical structures. The weaver would suspend fibers from a tree branch, which was parallel to the ground, or he might fashion a vertical loom using tree limbs and branches. Below is an image of a warp-weighted loom depicted on a terra cotta Greek vase. The picture gives us clear information about early loom construction, tools used, and weaving processes.

Ex. 3. Terra cotta vase; Greek, 560 B.C.E.

Warp ends were tied over the top branch and were then placed under tension with stones or weights made of baked clay. Initially, weaving was accomplished by walking back and forth in front of the loom, lifting one warp thread at a time, and passing the weft under and over the warps from side-to-side. Working against gravity, wefts were pushed up into place with the weaver's hands or with a crude comb. Since every warp thread had to be lifted by hand, the process was slow and tedious. In time, a large tapered stick was introduced and was used to carry the weft across the warp and to push, or beat, the threads up into place. Early on, this stick resembled an over-sized needle, but ultimately, it became the shuttle, a tapered device on which weft yarn is wound and which passes between warp threads.

One of the most useful discoveries during the evolution of weaving was the realization of the shed, an opening in the warp through which the weft thread travels, resulting in a web. Initially, weavers had to raise every warp thread by hand and then pass the weft thread through bit by bit, but in time, weavers found ways to create sheds. One such way involved the insertion of a rod under every other warp thread. The rod, called the shed stick, could then be lifted or turned on its side, revealing a clear passage for the weft. The creation of the shed hastened weaving time, but the weaver still had to continually use one hand to hold up the rod in order to pass the shuttle through the shed.

The Development of the Loom

Webster defines a loom as "a frame or machine for interweaving yarn or threads into a fabric, the operation being performed by laying lengthwise a series called the warp and weaving in across this other threads called the weft, woof, or filling." Another definition, which is quite to the point: "A loom is the framework across which threads are stretched for the weaving of cloth." Since the warp functions as the backbone of the weaving structure, choosing a warp requires knowledge of the nature of fibers, in that warp yarns workbest if they have certain characteristics. The warps should be fairly smooth and should not have too many slubs or bumps. The warps should be plied yarns with adequate tensile strength, strong enough to withstand a certain amount of weight. Types of warp yarns used in historic times varied depending upon what plants or animals were native to a particular region. Cotton, wool, linen, and silk were favorite warp yarns of our ancestors and are still some of the most popular choices of contemporary weavers. Today's fiber artists use the same general principles as people during primitive times, for the fundamental aspects of handweaving have remained unchanged. Since many loom types have evolved over the centuries, we will discuss a selection of looms, starting with the simple and progressing to the more complex.

Weaving in Switzerland

Another area where artifacts of prehistoric weaving were found was the region of the Swiss Lake Dwellers, a culture dating back to about 5000 B.C.E. Here archeologists discovered woven linen scraps and spinning whorls, an indication that this culture had advanced knowledge of the subject.

Weaving in China

One of the most fascinating stories in the development of weaving comes from China. Several legends have been told about the discovery of silk, but there is one that has become the most noted of all. In the 27th century B.C.E., during the reign of Emperor Huang-Ti, a disease began to destroy the trees in the royal mulberry grove, so the emperor asked his empress to study the problem. Empress Hsi-Ling-shi spent time in the groves and noticed that small white worms were devouring the mulberry leaves. The worms then would crawl to the naked stems below where they would spin silvery, white cocoons. According to legend, Empress His-Ling-shi took some of the small cocoons to her apartment for closer observation, and there one of the cocoons accidentally fell into a bath of warm water. As water was absorbed into the cocoon, the tiny pocket began to unravel revealing a delicate network of fibers. The empress pulled a small filament from the network and realized the fiber was a continuous thread, hundreds of feet long. In fact, one cocoon can contain a single filament measuring over 1,000 yards. With the discovery of the silk fiber, His-Ling-shi found the secret of acquiring a very rare and exquisite thread, one that could be used without first going through the spinning process.

As weavers in China began using silk in many of their elegant garments and tapestries, and later, as fabrics began to be exported, people outside of China became envious and somewhat resentful of the discovery. Despite the interest and curiosity of others, the process of cultivating silk remained a mystery and a well-kept secret to the outside world for over 3000 years.

Weaving among the ancient Hebrews

Ancient fabrics from the Hebrew world date back as early as 3000 BC. Many of the yarns produced by the Hebrews were multi-plied, up to 72 ply, and the Bible indicates that some garments contained threads made of gold and silver. Wool was used more than any other fiber in this area, white wool being the finest. Course wool, black wool, and horsehair were considered secondary. Hebrew priests were required to wear pure linen. In the Old Testament (Deuteronomy 22:11), we are given detailed information about the practices of early Hebrew weaving. One law stated that it was prohibitive to wear fabrics made from a mixture of linen and wool fibers. Another Hebrew law forbade married women to spin yarn in public places or to spin yarn at night by moonlight. Because of the active nature of the spinning process, such an act might reveal a woman's arms, and if this were to occur, it would give a husband the right to divorce his wife.

Weaving in Mesopotamia

Mesopotamia, located between the Tigris and Euphrates rivers, became the center for commerce and was known to have textiles of quality. Because of its location, Mesopotamia was a major pathway for trade and for other developing civilizations. Archeologists found Sumerian clay tablets dating back to 2200 BC, which provided evidence of a flourishing weaving industry. The Babylonians followed with weavers who specialized in certain areas of the craft. For example, embroidery became such an important textile art form to this culture that the technique came to be known as "Babylonian".

Weaving in Egypt

Sealed tombs in Egypt's Nile Valley have brought forth fabrics dating back as far as 5000 BC. The predominant fiber found in Egypt was linen, a product of the native flax plant. A simple plain-weave pattern, an over-under stitch, was used for the construction of cloth. This plain weave structure was the dominant stitch until about 2500 BC. Wool was accessible in Egypt, as well, but was considered a fiber of the lower classes, namely, herdsmen and farmers.

Wool garments are rarely found in Egyptian tombs. In fact, Egyptian law placed certain restrictions on the use of wool. One such law forbade members of the priesthood to wear wool next to their skin or to wear wool into a place of worship. Cloth make from wool was thought to be crude and irreverent. Fabric made with cotton was much more acceptable and has been found in Egyptian tombs, but cloth made with linen was always considered the highest quality material and was used in mummy wrappings of the aristocracy.

The Prehistoric Origins of Weaving

With modern sophisticated methods of radiocarbon testing and DNA testing, today's scientists are much better able to assign accurate dates to archeological findings than they were even a decade ago. The exact date of the first handwoven works, however, continues to remain a mystery. Nevertheless, there is evidence of cloth being made in Mesopotamia and in Turkey as far back as 7000 to 8000 BC.

Since fabric remnants have been difficult to find, to say the least, some historians use other sources as guides in piecing together our textile heritage. One valued artifact is the funerary model of a weaver's workshop, which was found in an Egyptian tomb. This model contains a horizontal loom, warping devices and other tools, and weavers in action. We can also take note of the garments worn by the people.

Ex. 1. Funerary model of a weaver's workshop. Egypt, 19th century B.C.E.

Another artifact, which is highly valued, is the piece of pottery below with the imprint of a textile structure etched in its exterior. It is believed that an early craftsperson formed this pot by lining the interior of a woven basket with wet clay. Heat was provided to shrink and harden the clay, at which time, the basket fell away leaving its mark on the outside of the pot.

Ex. 2, Neolithic pottery with weave imprint, found in the Thames near Mortlake; from the British Museum.

A Brief History of Weaving

Weaving is the systematic interlacing of two or more sets of elements usually, but not necessarily, at right angles, to form a coherent structure. No one knows when or where the weaving process actually began, but as far back as there are relics of civilized life, it is thought that weaving was a part of developing civilizations. Because of the perishable nature of textile goods, information found about the beginning stages of weaving is sketchy, and tracing the development of textiles is a difficult task and a tremendous challenge. Due to nature's hazards of erosion, climatic conditions, insects, and fire, few examples of early woven fabrics survived. Therefore, much of what is written about primitive weaving is based on speculation. There are, however, certain circumstances under which remnants of fabrics have survived: arid regions, bog lands, sealed tombs, and extremely cold areas. Because of these artifacts, we are fortunate to have some examples of early textiles and weaving tools.

The everyday needs of our prehistoric ancestors probably led them to create objects using fiber as a medium. It is thought that ancient humans instinctively used weaving as an aid in their quest for basic needs of food, shelter, and clothing. It is not unlikely that people might have realized the possibilities of the woven structure after observing spider webs, birds' nests, or the construction of a beaver's dam. These findings probably led to the interlacing of twigs or vines, and resulted in netting which surely assisted humans in catching fish and trapping game. In addition, by using twining or braiding techniques, it is likely that primitive people learned to make mats to cover floors of huts, which helped insulate against dampness or cold. Eventually, people used weaving skills to make exterior coverings for shelters, so they would be somewhat protected from harsh weather and/or from predators.

Archeologists believe that basket making and weaving were probably the first "crafts" developed by humans. Once primitive people learned ways of creating a woven structure, the possibilities were endless: netting, coverings for huts, containers for goods, carriers for the young, rugs, blankets, hammocks, pouches, body coverings. Along with our ancestors' ongoing quest for survival, there is evidence of an unconstrained desire by humans to embellish the objects created. The use of natural dyes on reeds or the combination of varying sizes and colors of weaving elements to create patterns, was likely an an attempt to express individualism and an aesthetic sensibility. Human beings naturally have a strong compulsion to be creative, and our records show that this trait was prevalent in our ancestors' lives thousands of years ago.

Research indicates that cultures on every continent devised crude looms and methods of making webs, and further study tells that us there was great similarity in the looms constructed and in the weavings produced.

HISTORY OF WEAVING

The origin and development of woven cloth is closely tied to the history of mankind. Thousands of years ago we developed the skills necessary to turn the raw materials around us into cloth for clothing and shelter.

Weaving, the lacing together of threads and yarns to form cloth has developed over thousands of years of discovery and experimentation. Coarse fabric, made from grasses and leaves, was the first step toward the development of the textiles we use today.

NON-WOVEN NOTES







SOME INTERESTING FACTS ABOUT TEXTILE

  • some of the linen fabrics found in Egyptian civilisation were so fine, that they had 216 warp threads per cm. while the finest linen woven in modern europe had only 140 warp threads/ cm
  • It is reported that linen robes of Egyptian kings, nobles and priests were of such fine structures that it was possible to draw them through a small finger ring. They were often called 'woven air'
  • The Pharaos of Egypt organised large spinning and weaving mills of Thebes, Penopolis, Memphis and other cities.
  • Egyptian followers of christianity were called copts.Their outstanding contribution to the textile history is the art of tapestry weaving with directly coloured wood and undyed linen which they perfected.
  • In egypt in (1304-1307), a fabric called Bukalemun, which changed its color with light was also made.
  • Mesopotamia, is the birth place as well as the cradle of the wool
  • Muslin name came from Mosul, a city in Persia
  • Art of Carpet weaving is believed to be known as 3600 BC, oriented an original manuscript in which it is stated that ofter conquering Ketsiphon (651 AD), the capital of Persia, the Arbas found a huge carpet representing a garden. This was called Spring of Chosroes.
  • In ancient Greece, weaving of woollen cloth was a house hold fashion. Later wool weaving becomes a separate occupation, carried by a class of citizens called textores from which the modern word textile came.
  • The famous Halen of Troy kept herself busy with the work of directing the spinning and manufacturing of costly woven cloth for garments by the maidens of the household.
  • The Word 'clew(clue)' came from a ball of woollen thread which as it was unwound was dropped on the ground by Theseus of Greece as he walked into the labyringth to kill the Minotous so that the thread would be a clue to guide him back to the entrance
  • A loom was a household furniture in the ancient Greece
  • The word 'cloth' is itself a Roman origin. Cloth was one of the three Fates, who wove human destiny, while Lachesis spun the thread of life, which was cut by Atropos, thus ending life.
  • According to the edict of the Roman Senate of 16th AD, wearing of silk robes by men was prohibited in Rome
  • Cambrai, an ancient cathedral town in North France, was prominent for the manufacture of smooth, thin, white linen, which took its name (Cambric) from the city where it was first woven.
  • Joseph Marie Jacquard was born in Lyons (France) in 1752, as the son of a weaver with his mother as pattern maker, a knowledge of the loom was his great inheritance. He brought certain improvements in the loom and Napolean granted him an annuity provided he worked in Lyons and perfected his invention. He did not invent or change the loom but he invented an attachment which by a series of cards with punched holes to correspond with simple or elaborate patterns, controlled the raising and lowering of warp threads. This principle is used in the modern Jacquard looms.
  • The word 'loom' came from the Anglo-Saxon word 'geloma' which means domestic utensil.
  • Silk--> according to a legend a princess Si-Ling-Chi, the wife of a great prince Huang-ti, saw in a garden a small worm, wrapping itself in a beautiful cocoon. She took greater interest when she found that other worms doing the same thing. she took one of them in her hand, and discovered that with great care, she could unwind the cocoon and obtain a fine thread of great length. From then onwards she nurtured the worms and years later she could gather enough yarn to make a robe for her husband.
  • In Japan during the Heian Period ( 795 to 1192) silk fabrics came to be valued as currency.
  • In 1542, Indigo became so popular that there was at least one indigo dyer in every village or town in Japan
  • Tie-and -Die work originated in Indonesia
  • Royal Purple or Tyrian Purple ( obtained from a small shell fish which was abundan in the water near Tyre), the royal color of the Roman Empire ( first few centuries of the Christian era) was so costly that the Roman Emperor Diocleian in 301 A.D. fixed the price of wool dyed with this dye at an equivalent of Rs. 3000 per pound in Gold. ( of course 1200 shell fish gave about 1 gm of the dye !!)

FIBER SPINNING

Fiber Spinning

Spinning Spinning is the twisting together of fibers to form yarn (or thread, rope, or cable). Earlier fiber was spun by hand using simple tools like spindle and distaff. Later the use of spinning wheel gained importance. Industrial spinning started in the 18th century with the beginning of the Industrial Revolution. Hand-spinning remains a popular handicraft.

Industrial spinning
Fibers can not be used to make clothes in their raw form. For this purpose, they must be converted into yarns. The process used for yarn formation is spinning. Spinning by hand was a slow and laborious process. Thus, Many implements and methods were invented for making it faster and simple. Eventually, the techniques were refined and industrial spinning started manufacturing yarn in various ways. The methods selected depend upon the factors such as the manufacturer's preference of equipment, the economic implications, the fibers to be used and the desired properties of yarn to be produced. Ring method is the oldest and the most used technique. Open- end spinning is another important method. The basic manufacturing process of spinning includes carding, combing, drafting, twisting and winding. As the fibers pass through these processes, they are successively formed into lap, sliver, roving and finally yarn. A brief description of the journey from fibers to yarns will help in understanding industrial spinning in a better way.

Raw  FiberThe raw fiber arrives at a spinning mill as compressed mass which goes through the processes of blending, opening and cleaning. Blending is done to obtain uniformity of fiber quality. Opening is done to loosen the hard lumps of fiber and disentangle them. Cleaning is required to remove the trash such as dirt, leaves, burrs and any remaining seeds. Carding is the initial straightening process which puts the fiber into a parallel lengthwise alignment. This makes the tangled mass of fiber ready to produce yarn. Now the fiber is called 'Lap' . The lap is treated for removing the remaining trash, disentangling and molding it into a round rope like mass called 'Sliver'. The sliver is then straighten again which is called Combing. In it, fine-toothed combs continue straightening the fibers until they are arranged in such a parallel manner that the short fibers are completely separated from the longer fibers. This procedure is not required for man made staple fiber because they are cut into predetermined uniform lengths. This process forms a 'comb sliver' made of the longest fibers. The combing process is identified with better quality because long staple yarn produces stronger, smoother and more serviceable fabrics.

Drawing pulls the staple lengthwise over each other. As a result longer and thinner slivers are produced. After several stages of drawing out, the sliver is passed to the spindles where it is given its first twist and is then wound on bobbins. 'Roving' is the final product of the several drawing-out operations. It is the preparatory stage for the final insertion of twist. Till now, enough twist is given for holding the fibers together but it has no tensile strength. It can break apart easily with a slight pull. The roving, on bobbins, is placed in the spinning frame, where it passes through several sets of rollers running at high speed and finally the 'Yarn' is produced of the sizes desired.

Spinning Machines Traditional v/s Modern Techniques
Hand spinning was replaced by powered spinning machines which was very fast. Initially it was done by water or steam power and then by electricity. The spinning jenny, a multi-spool spinning wheel significantly reduced the amount of work required to produce yarn. A single worker was now able to work eight or more spools at a time.


Spinning MachinesThen came the spinning frame which produced a stronger thread than the spinning jenny. As it was too large to be operated by hand, a spinning frame powered by a waterwheel was invented. It was then called the water frame. The elements of the spinning jenny and water frame were combined to create the spinning mule.

Then came the spinning frame which produced a stronger thread than the spinning jenny. As it was too large to be operated by hand, a spinning frame powered by a waterwheel was invented. It was then called the water frame. The elements of the spinning jenny and water frame were combined to create the spinning mule.

Spinning

What is Spinning?

The Spinning is a technological system in which twist is inserted to the fibers and yarn is produced. The spinning process includes many processes which transforms the bales of raw cotton into a yarn ready for weaving. The term "spinning" can refer to the whole activity or just to the final process of making the yarn. The raw cotton arrives in the form of large bales. These are broken open and a worker feeds the cotton into a machine called a "breaker" which gets rid of some of the dirt. The cotton may not be consistent in quality from bale to bale therefore samples are taken before getting bales in best quality.

Following processes are involved in manufacturing of yarn.

Mixing

Mixing of cotton brought to make a uniform blend in order to make a uniform yarn with high quality parameter in order to avoid any shade problem. For this purpose, the number of bales are mixed to get uniform results. Raw cotton is purchased from best cotton growing areas of country and also cotton bales are imported from foreign countries. For stocking and mixing, sandwich-mixing technique is used.

Back Process.

Back process of yarn manufacturing process is contributed by following sections.

a. Blow Room Section
b. Carding Section
c. Drawing Section
d. Combing Section
e. Simplex (Roving formation)

a) Blow Room

In the Blow room section cotton is opened and cleaned through the following machines.

1. Auto Bale Plucker
2. Single Roller Cleaner Machine "B11"
3. Chute Feed System
4. Loptex (Contamination Control System)

b) Carding.

In this section cotton is opened cleaned and formed slivers of particular thickness. Each unit of Hussain Group has one of the best carding machines in the world. Following machines are used in this process

1. Crosrol MK 5D
2. Trutzchler DK 903


c) Drawing Section


In the Drawing section sliver is doubled, blended and drafted to parallel all fiber and to control and straighten the hooks present in cotton to form a uniform & even sliver for production of high quality yarn of very low CV%.

Hussain Group has following machine which are used in this process.

1) DX7A Toyoda Japan as Breaker drawing
2) RSBD 30 and RSBD 30C as Finisher Drawing

d) Combing Section.

In this section, 20% excessive waste (comber noil) is extracted. In this process, latest machinery Reiter E 62 (Swiss) is used which is very high quality performance machine.

e) Simplex Section.

In simplex section, sliver is fed and roving is produced. Finisher sliver is drafted and very low twist is inserted to form Roving. Roving is final preparatory shape of yarn in Back process stage, which will be converted into yarn in ring department.

Yarn Production Process

Ring is process where yarn is manufactured with clear specification of count and other specifications after Roving is creeled on ring machine from Simplex department. This roving is drafted and twisted to form yarn.