Derivatives of Elementary Weaves

7/27/2019 Derivatives of Elementary Weaves

1/20

Chapter ThreeDerivatives of Elementary Weaves

These weaves are constructed by means of

developing elementary weaves.

They are derived by changing the floats, number ofshift, direction of diagonal lines, from plain, twill, and

sateen/satin weaves, and retain their structural features.


2/20

3.1 Plain weave derivatives

3.2 Twill weave derivatives

3.3 Satin/sateen derivatives

The derivatives of elementary

weaves include:


3/20

3.1 Plain weave derivatives. 3.1.1 Rib weaves

3.1.2 Hopsack weaves


4/20

3.1.1 Rib weaves Rib weaves are obtained by extending the

plain weave in either warp or weft direction.

Two kinds of rib weave:

warp rib weaves

weft rib weaves


5/20

1. Warp rib weaves

Warp ribs are

constructed by inserting

several picks insuccession into the same

shed of an ordinary plain

weave. This forms a ribeffect across the fabric.

(see Fig. 3.1)


6/20

Regular warp rib

The same number ofpicks are inserted in each

successive rib, giving thefabric a regular appearance.

See Fig. 3.3

This figure shows 3 picks

are inserted into each shed


7/20

Irregular warp rib

A variation in the width ofrib is achieved by inserting

different numbers of picks

into each successive shed. See

Fig. 3.4.


8/20

The warp rib weave diagram is

drawn as the following steps. 1) Calculating the weft repeat Ry :

Ry = numerator + denominator

Ro = 2

2) Drawing the first endaccording to the fraction given.

3) Drawing the second endopposite to the first one.

Example: 2/1 irregular warp rib


9/20

2. Weft rib weaves

Weft ribs are constructed

with several warp threads usedas one when interlacing with

each pick in succession. They

form a vertical rib effect in the

fabric. (See Fig. 3.5 two ends areused as one)


10/20

Regular weft rib An regular number of ends are used to

form each rib, giving the fabric a regular

appearance. See Fig.3.6


11/20

Irregular weft rib A variation in the width of the rib is

achieved by varying the number of ends in

each successive rib, as shown in Fig. 3.7.


12/20

The weft rib weave

diagram is drawn as following 1) Calculating the warp repeat

Ro.

Ro = numerator + denominator

Ry = 2

2) Drawing the first pickaccording to the fraction given.

3) Drawing the second pick

opposite to the first one.

Example: 2/1 Irregular weft rib


13/20

Notes:

Warp rib weaves produce ribs running weft-way

Shown in Fig.3.1

Weft rib weaves produce ribs running warp-wayShown in Fig.3.5


14/20

Applications Rib gives a more flexible cloth than plain weave

and has many applications.

Fabrics are woven in silk, cotton, wool and

man-made fibers. Their end uses range from dress

fabrics, coats, suits, millinery, ribbons and wedding

to upholstery and drapery.


15/20

3.1.2 Hopsack weaves

Hopsack weaves are constructed byextending the plain weave both vertically

and horizontally. See Fig. 3.8


16/20

Regular hopsack Regular hopsacks are woven with the same

number of ends and picks and the same yarn count.

Equal warp floats exchange with equal weft floats.See Fig. 3.9


17/20

Irregular hopsack

Different units of hopsack are arrangedin one repeat, with the distribution of warp

or weft floats being equal or apredominance of either. See Fig. 3.10


18/20

The irregular hopsack diagramis draw in following steps.

1) Calculating the repeat:

Ro

= Ry

= sum of the numerator +sum of the denominator

2) Drawing the first end and first pick based on the

fraction.

3) Based on the first pick, drawing the ends which have

warp float same to first end.

4) Drawing the other ends opposite to the first one.


19/20

Applications

Hopsack weave fabrics are

less stiff than plain due to

its fewer intersections, andthey have smooth and

lustrous surface. Hopsacks

are suitable for Apparel,drapery, and are often used

for selvedge of other fabrics.

Regular hopsack sample

Irregular hopsack sample


20/20

Home works:

Drawing the weave diagrams

1. 2/2 warp rib;

2. 2/2 weft rib;

3. 2/2 hopsack;4. 3/3 hopsack;

5. warp rib

6. 3/1 weft rib,7. hopsack

8. hopsack

21

22

23

23

12

21

Derivatives of Elementary Weaves

Documents

Transcript of Derivatives of Elementary Weaves