Weaving (1)

Introduction to Textile Manufacturing (TEXT-175)

Fabric Formation: Weaving

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Textile Fabrics

Textile Fabrics

Textile Fabrics

Weaving

Weaving is one of the most common methods of fabric formation by interlacing of warp and weft threads.

Yarn Preparation before Weaving

Yarn Preparation before Weaving

Warping onto a Section Beam

Warping onto a Section Beam

Warping from Section Beam onto a Weaver’s Beam

Yarn Preparation before Weaving

Weaving

Essential Weaving Operations

• Shedding• Picking• Beating up• Taking up and letting off

*A looped bundle of yarn is known as a hank in textile terminology.

SheddingRaising specific warp yarns by means of a harness or heddle frame

SheddingRaising specific warp yarns by means of a harness or heddle frame

PickingInserting filling yarns through the shed

PickingInserting filling yarns through the shed

Beating up (Battering)Pushing filling yarns firmly in place by means of the reed

Beating up (Battering)Pushing filling yarns firmly in place by means of the reed

Taking up and letting offWinding the finished fabric on the cloth beam and releasing more of the warp

from the warp beam

Taking up and letting offWinding the finished fabric on the cloth beam and releasing more of the warp

from the warp beam

Types of Weaving

• Shuttle Loom Weaving

• Shuttleless Loom Weaving

Types of Weaving

• Shuttle Loom– Conventional loom that utilizes a shuttle containing a

bobbin of filling yarn (weft/pick) passing through the warp (warp/ends) shed

– Oldest kind of loom– Many disadvantages (slow, damages thread, noisy)– Examples: Handloom, Power looms, Circular etc.

Types of Weaving

• Shuttle Loom

Types of Weaving

• Shuttleless Looms– Any modern loom that overcomes the

disadvantages of a shuttle loom by eliminating the use of shuttle for weft insertion

– Examples: Projectile, Airjet, Rapier, Waterjet etc.

Shuttleless Looms

• Missile or Projectile Looms– The missile or projectile is a small light,

light, gripper device propelled across the loom, pulling filling yarn behind it

– Device smaller than a flying shuttle– Several missiles used on one loom– Produces very wide fabric– Not suitable for fragile fabrics

Shuttleless Looms

• Missile or Projectile Looms

Shuttleless Looms

• Rapier Looms– Uses a rapier device to pull filling yarn

through warp shed, across the loom width– The rapier is a metal rod, either flexible or

rigid, with a weft gripper at the end– Rapier mechanism is more capable of

producing delicate fabric as compared to missile weaving

Shuttleless Looms

• Rapier Looms

Shuttleless Looms

• Jet Looms– Jet looms take the filling yarn across the loom by

using high speed jet of either air or water– The force of air or water carries the yarn across

the loom– Faster than missile or rapier looms with higher

picks per minute (ppm)– Jet looms cause no abrasion to the yarn unlike

missile or rapier– Water jet ideal for hydrophobic fibers

Shuttleless Looms

• Airjet Looms

Fabric Features

• Selvage• Warp and filling yarns• Face and back• Top and bottom• Yarns per inch

Selvage (Selvedge)

“A Selvage is the lengthwise edge of a fabric.”

Identifying Warp & Filling Yarns

• Selvage: The warp yarns will always be parallel to the selvage.

• Yarn sizes: Usually warp yarns are thinner so they will abrade less as they pass through the loom.

• Stretchability: Usually there is more elongation in the width-wise direction.

• Yarns per Inch: Usually, there are more warp yarns per inch than filling yarns per inch

Yarns Per Inch

• The yarns per inch in a fabric is given by two numbers with an x between them.

• For example, 80 x 74 (pronounced eighty-by-seventy-four) means 80 yarns per inch in the warp and 74 yarns per inch in the filling.

• The yarns per inch in the warp and in the filling is called the fabric count or thread count. (It should not be confused with yarn count, which refers to the degree of fineness in yarns!)

Basic Fabric Weaves

• There are three basic weaves:– Plain weave– Twill weave– Satin weave

• All other weaves are a variation or combination of these weaves.

• The type of weave used in a fabric depends upon the fabric’s desired appearance and performance.

Basic Fabric Weaves

Plain Weave

• Simplest and most inexpensive• Requires only two harnesses• Each filling yarn goes alternatively

under and over a warp yarn across the fabric width

Twill Weave

• Produces diagonal lines on cloth• In a right-hand twill, the diagonals

run upward toward the right, and in a left-hand twill, the diagonals run upward toward the left.

• Denim

Satin Weave

• Similar to twill, but there is only one interlacing for each warp, and each weft yarn.

• No interlacing ever touch, or are adjacent.

• Long floats

Weave Floats

When one yarn does not interlace with the next adjacent yarn, but passes over two or more

adjacent yarns, it is said to be a float.