Weaving Basics

History of Weaving

 

There is evidence that the first weaving looms were in use 4,000 years ago. It was around this time that most civilizations developed their own version of the hand-operated loom. The Weaver’s Craft Guild was created in 1100 A.D. in England to support the craft of weaving. For centuries, weaving remained strictly a cottage industry where all weaving took place in the home. It wasn’t until the industrial revolution in the 1700s that the factory system became more prevalent that the cottage industry. This was the beginning of the modern-day factories. Weaving technology has evolved from the first simple hand loom to today’s high-tech machines.

 

John Kay & the Flying Shuttle

The first major technological advance in weaving came when John Kay invented the flying shuttle in 1733 which allowed the shuttle to be thrown through the shed without having to be placed manually through the warp yarns.

 

Joseph-Marie Jacquard & the Jacquard Loom

This was followed by the development of the jacquard loom by Joseph-Marie Jacquard between 1801 and 1805. The jacquard loom is considered by most to be the first key punch operated, computer-like system ever made. It was so revolutionary that the French government purchased the system five years later in order to control its use. Because the system threatened the hand weavers’ monopoly they revolted, burning many jacquard looms and forcing Jacquard himself to flee his hometown for fear of his life.

 

The Knowles Brothers & the Steam-Powered Loom

In 1837, Lucius J. and Francis B. Knowles developed the first upright loom powered by a steam engine but they were not granted a patent for their design until 1856. By the end of the Industrial Revolution, ninety percent of all weaving looms in North America were automated.

 

These major innovations in weaving resulted in higher-quality fabric and a faster rate of production.

 

Modern Developments

In the last 100 years, there have been significant developments in weaving especially in the form of shuttle-less weaving systems. Developments in weaving technology continue to improve the quality of fabric as well as the increasing rate of production.

 

Covering an extremely wide range of applications, wovens are a key element in the apparel, home, and industrial fabrics industry. Whether designed for fashion or constructed for industrial applications, wovens are used for more applications than any other system of fabrication.

 


 

Warping, Slashing, Drawing-In, & Tying-In

 

Weaving is the interlacing of yarns to form a fabric.

 

For a fabric to be considered woven, it must have three properties:

 

  1. Yarns in a warp direction
  2. Yarns in a filling or weft direction
  3. The interlacing of these yarns

Warping

 

The number of threads per inch for the warp yarns is referred to as the slay, ends per inch, or warp count.

 

The number of threads per inch for the filling yarns is referred to as picks, pick count, or filling count.

 

The edge of the fabric is called the selvage. It is designed to give stability to the edges of the fabric so that the fabric will not fray during subsequent processing in the textile plant.

 

How do we get the yarns interlaced to form a fabric? Warp yarns must be arranged in a parallel manner and precisely controlled so that the weft yarns can be inserted to form a fabric.

 

At the back of the loom is a loom beam that contains all the warp yarns needed to manufacture the desired fabric. After the yarns leave the loom, they go over a whip roll that is part of the warp yarn tensioning system. Each individual yarn then goes through a drop wire that is part of the loom’s stop motion system that helps prevent mechanical defects from occurring during weaving.

 

Next, each yarn goes through a heddle eye that is mounted in a harness. The harnesses are used to raise and lower the yarns to achieve the desired design. After leaving the harness, the warp yarns are evenly spaced by a reed. After a filling yarn is inserted at a right angle to the warp, the reed is used to force the filling yarn into the fabric. Then the fabric passes through take-up rolls and is then wound onto a roll.

 

A loom beam contains thousands of individual yarns placed side-by-side onto a flanged beam. In order to have the necessary number of yarns on the loom beam, you have to start with yarn packages in a creel. It is not possible to put all the yarns needed for weaving in a single warp or creel.

 

For example, if a warp beam needs 3,200 ends and the creel holds only 400 ends, then a section beam will be made on the warper. Therefore 8 section beams would have to be made to accumulate the needed 3,200 ends.

 

Yarn packages are first placed in a creel from which they are wound onto a section beam or dye beam. The path the yarn follows on the creel is through tension devices and stop motions.

 

Next, the yarn passes through a reed or comb that guarantees even spacing and a yarn sheet width that matches the width of the section beam. In some cases, the section beam is perforated for yarn beam dyeing. For some special types of yarn-dyed warps, such as indigo for denim, a system called rope or ball warp dyeing is used. If rope dyeing of yarn is to be performed, then ball warps must be manufactured.

 

Ball warps are made using a creel that is set up as with other forms of warping. However, the head stock is set up differently in order to condense the sheet of yarn into a rope. The sheet of yarn is passed through a trumpet-like device to collapse the yarn before it is wound into the ball. The yarn is then wound onto the log like a huge package of yarn. By traversing the rope back and forth across the face of the ball, the package is built evenly with constant tension. The ball warps can be from 500 to 25,000 yards in length. They are added together behind the rope dyeing range in a magazine creel to form a dye set.

 

The dye set is always a multiple of the number of beams in the slasher set. For example, if there are 12 beams in the slasher set, there will be 12, 24, or 36 balls in a dye set. The yarn is then unwound from the balls and is passed through the dye range. After the yarn has been dyed and dried, it is coiled into a large tub or moveable storage device. This tub of yarn is then taken to the re-beaming area where each end is separated and re-warped onto a section beam.

 

 

Slashing

 

Whether the yarn is placed on a section beam, a perforated beam, or processed in the ball warp process, the next step in processing is slashing. The section or dye beams are placed into a slasher creel or slasher magazine where the ends from each beam are added together so they can be sized and wound onto a single loom beam. Once assembled on a loom beam, some yarns such as ply and filament can weave without additional processing. But most yarns require a sizing with chemistry to improve the weaving performance of the yarn. This process is called slashing.

 

The slasher is composed of a section beam creel, sizing boxes, a drying section, yarn separators or bust rods, and head stock. A pre-wetting box can be located in the creel and sizing boxes. The sizing boxes apply the chemistry that encapsulates the yarn. Benefits include gluing down hairs, yarn strengthening, and lubrication which protects the yarn and loom parts. During this process, it is extremely important that each end be kept separate and parallel to adjacent yarns.

 

 

Drawing-In

 

After sizing, the warp ends must be placed through the proper devices for weaving in the correct order for the desired design and color pattern. This process is called drawing-in, where each warp end on the loom beam is pulled or drawn through a drop wire, a hettle that is in a harness, and then finally through a dent in a reed. This is one of the most important steps in weaving since an incorrect color or weaving pattern will result in second-quality cloth.

 

 

Tying-In

 

When changing warps on a loom with an identical drawing in draft and warp end count, a knotter may be used. The knotter will tie the new warp ends onto the warp ends already present in the loom. The knots can then be advanced through the drop wires, hettle, and reed. This manual procedure to replace a depleted warp with a new identical warp can take less than one hour. The changing of the draw to a new one is considerably slower.

 

 

TERMS TO KNOW (click to flip)

Kay, John

The English inventor credited with inventing the fly shuttle loom in 1738.

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Flying Shuttle

The shuttle is a boat like device that contains a quill (or spool) of filling yarn. In hand weaving, the…

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Jacquard, Joseph Marie

The French inventor of the head motion that bears his name. This head motion device is cited as being the…

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Jacquard Loom

A loom that is equipped with a jacquard head. Each warp end on a jacquard loom is controlled individually by…

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Knowles, Francis B. & Lucius J.

Together, Lucius J. Knowles and Francis B. Knowles developed the first upright loom powered by a steam engine, leading the…

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Warping

The act of placing yarn onto a warp beam or log from yarn supply packages located in a creel.

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Slashing

The process of applying chemistry to warp yarns to protect them from the rigors of weaving. This process is also…

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Drawing-In

The process of taking warp yarns off the loom beam and pulling each end through its own Drop Wire, heddle,…

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Tying-In

The process of typing a new warp beam sheet of yarn to the old warp yarns on a loom when…

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