2.1 Woven fabrics

Question 1

Dobby weave:

Answer 1

A dobby fabric made with a dobby attachment and characterised by small geometric- type designs

Question 2

Float:

Answer 2

A portion of a warp or filling yarn that extends over two or more adjacent filling yarns to produce a design or a satin surface

Question 3

Harness:

Answer 3

A frame that holds the heddles in position in a loom; it allows for the raising or lower- ing of groups of yarns to form the shed for weaving

Question 4

Heddles:

Answer 4

A cord, thin metal strip or metal wire with a hole near the centre through which the warp yarn is threaded

Question 5

Jacquard:

Answer 5

The original Jacquard attachment which allowed individual control of each warp yarn to permit the construction of highly complex woven designs; today the term is used to describe complex designs in both woven and knitted fabrics

Question 6

Leno weave:

Answer 6

A firm open-weave fabric in which pairs of warp yarns are twisted around each other between each filling yarn

Question 7

Loom:

Answer 7

A machine used to weave fabrics

Question 8

Pile weave:

Answer 8

A weave in which an additional set of warp or filling yarns is interlaced to form the pile or raised effect

Question 9

Plain weave:

Answer 9

The simplest of the three basic weaves, in which each filling yarn passes successively
over and under each single warp yarn in alternating rows

Question 10

Satin weave:

Answer 10

One of the three basic weaves characterised by floats that run in the warp direction on the face in such a manner as to reflect light, producing gloss, lustre or shine

Question 11

Shed:

Answer 11

The opening, created by harness movement, between sheets of warp yarns through which filling yarns are passed

Question 12

Shuttle:

Answer 12

A boat-shaped device that carries the filling yarn back and forth across the shed

Question 13

Twill weave:

Answer 13

One of the three basic weaves in which yarns are interlaced in such a way that they create a dominant diagonal line

Question 14

Warp yarns:

Answer 14

Yarns that run parallel to the selvage, that is, in a lengthwise direction of the fabric (also called ends)

Question 15

Weft yarns:

Answer 15

Yarns that run perpendicular (at right angles) to the warp yarns and selvage of the fabric (also called filling yarns, picks or woof yarns)

Question 16

Ravelling:

Answer 16

A thread or yarn that has become separated from a woven fabric

Question 17

The kit contains the following:

Answer 17

(1) a technical manual
(2) a glossary
(3) cross-reference fabric swatches

Question 18

2.1.2 Basic weaves

Plain weave

Answer 18

This is the simplest and also the least expensive weave type. The weft threads pass over and under one warp thread alternately. Plain weave fabrics are more snag resistant but wrinkle more, and have a lower tear strength compared to the other basic weaves. The two sides of the fabric look the same – there is thus no difference between the face or back of the fabric. Examples of cloth woven in plain weave are muslin, percale, calico, cheesecloth, gingham, batiste, lawn, organdy, handkerchief linen and chiffon.

Question 19

Variations of plain weave

Answer 19

Basketweave

Riborcord weave

Question 20

Basket weave

Answer 20

Basket weave is a type of plain weave with two or more warp yarns interlaced as a unit with two or more filling yarns. Examples are monk’s cloth, Hardanger cloth, Oxford cloth and hopsack.

Question 21

Riborcord weave

Answer 21

This is also a variation of plain weave. Heavy yarns are used in either the warp or filling direction, or by grouping yarns in specific areas of the warp or filling, or by having more warp yarns than filling. Examples are broadcloth, poplin, faille, bengaline, grosgrain, dimity and Bedford cloth.

Question 22

Twill weave

Answer 22

Twill-weave fabrics are characterised by a diagonal line on the surface of the fabric. The yarns in twill fabrics are usually tightly packed, producing a strong and durable cloth. They are more expensive to produce than plain weaves. Twill weaves are more wrinkle resistant, more resistant to soiling and showing soil, heavier, and have a more pliable drape and hand compared to plain weave fabrics. They are, however, more prone to ravelling. The prominence of the twill line depends to some extent on the length over which the yarns ”float” across each other. Twill fabrics have either a left- or right-hand diagonal and they can be weft-faced (more weft yarns floating on the face), warp-faced (more warp yarns floating on the face) or balanced (warp and weft equally prominent). In the simplest twill weave, the filling crosses over two warp yarns and then under one, over two, under one, and so on. In the next row, the sequence begins one yarn further on. There are a number of types of twill weaves, herringbone twill being one of them.

Question 23

Examples of twill weave

Answer 23

chino, drill, denim, gabardine, serge, surah, wool sharkskin, some flannel and some tweeds.

Question 24

Satin weave

Answer 24

Satin fabrics have long floats on the surface. A float is a portion of a warp yarn that ex- tends over two or more adjacent filling yarns. These long floats reflect light and create a shiny and smooth appearance. Satin fabrics are also frequently used as lining fabrics as they easily slip over other fabrics. Satin fabrics are not as durable as plain or twill weaves because the floats are easily snagged. Examples of satin weaves are antique satin, slipper satin, bridal satin, sateen and moleskin. A satin is a warp-faced fabric, whereas sateen is a weft-faced fabric.

Question 25

2.1.3 Complex weaves

Answer 25

``` Dobby weaves Jacquard weave Leno or gauze weave Pile weaving Double weave ```

Question 26

Dobby weaves

Answer 26

Dobby weaves have small designs, such as dots or geometric patterns. The designs are angular and repetitive; even floral designs appear geometric. A dobby loom can have as many as 24 to 40 harnesses. Dobby designs are always small and do not make use of long floats. Examples of dobby weave are birdseye, huckaback and piqué.

Question 27

Jacquard weave

Answer 27

Fabrics such as damask, brocatelle and brocade, which have highly complicated woven designs, are woven on Jacquard looms. The Jacquard mechanism (named after its inven- tor, the Frenchman Joseph Jacquard) can lift one or more warp yarns independently of the others. The pattern to be woven is punched out on cards, reminiscent of computer punch cards or the cards used for machine knitting. Today the Jacquard loom is controlled by computer and not by cards. Bear in mind that a Jacquard fabric does not have holes in it; the holes are in the cards which control which warp yarn will be lifted.

Question 28

Note the differences between brocade and damask.

Answer 28

Damask is a reversible fabric with a figured design on a satin-weave background, usually only in one colour. It is flatter than brocade. Brocade has a more prominent, raised design on the front with the coloured yarns not being used carried as long floats on the back of the fabric. Brocade, unlike damask, has only one right side. Tapestry-like fabrics are also made on Jacquard machines. These fabrics have highly patterned designs on the face with the same designs, but in a different colour, on the back. Tapestry-likefabric,frontandback The Jacquard principle is used for weaving, knitting and lace making.

Question 29

Leno or gauze weave

Answer 29

In leno weave, pairs of warp yarns are twisted around each other between filling yarns. Examples are grenadine, marquisette and interlock embroidery canvass.

Question 30

Pile weaving

Answer 30

A woven pile fabric has an extra set of warp or weft yarns interlaced with the ground warp and weft in such a way that loops or cut ends stand up densely on the surface of the fabric. Note that weaving is not the only way in which a pile fabric can be created. It can also be done by tufting, knitting or sew-knitting, but then we cannot talk of pile weaving. In some pile fabrics, such as velveteen and corduroy, an extra set of weft yarns floats over three or more warp yarns. After the fabric has been woven, these floats are cut and brushed to form a pile. In other pile fabrics such as velvet, velour and Wilton and Axminster rugs, the pile is formed from an additional set of warp yarns.

Question 31

Warp pile fabrics can be made by any one of three methods:

Answer 31

(1) the wire-cut pile method, (2) the looped pile or terry cloth method, or (3) the double-weave method.

Question 32

Double-weave fabrics

Answer 32

Double-weave fabrics consist of two sets of warp yarns, two sets of weft yarns, and some- times, a fifth set of yarns that holds the two layers together. Warp-pile fabrics such as velvet are often constructed as a double-weave fabric.