Fibers and Polymers 2011, Vol.12, No.1, 137-141 DOI 10.1007/s12221-011-0137-x

New Production Method for a Plain Weave Figured Fabric

Sungmin Kim* and Joon Seok Lee1

Department of Polymer and Fiber System Engineering, Chonnam National University, Gwangju 500-757, Korea1School of Textiles, Yeungnam University, Gyeongsan 712-749, Korea

(Received March 5, 2010; Accepted December 5, 2010)

Abstract: A new production method for figured fabric has been developed. The figured fabric generated in this study is a plain weave piled fabric and it shows the same figure on both sides unlike those fabrics woven on dobby or jacquard looms. It is woven by a specialty yarn called the chenille yarn which is obtained by separating each warp of a base fabric woven in leno structure. The base fabric is woven by inserting different colored weft each time in a certain sequence arranged according to the target figure image. A CAD software and a computerized controller have been developed to control all the motions of a conventional rapier loom and to handle the numerous weft insertion schedule efficiently.

Keywords: Figured fabric, Plain weave, Chenille yarn, CAD, Computerized loom controller

Introduction

Recently, the establishment of a quick-response system

through comprehensive automation and the development of

highly value-added products have become very important in

textile industry [1]. One of the most famous value-added

textile products is the figured fabric, which has a variety of

colorful figures created especially by dyed yarn. Although it

has a considerable potential demands not only in fashion

goods but also in upholsteries, its production and application

has been limited due to its high production cost [2]. Besides

the high maintenance cost, dobby and Jacquard looms have

an intrinsic weakness that the fabrics woven on those looms

inevitably have a different look on each side. Usually the

back face of the fabric has a bad look due to long floating

wefts [2-4]. Many researchers tried to develop more efficient

methods but such problems could not be solved perfectly

because each approach was based on almost the same

principles with those looms [5].

In this study, a new fabrication method of figured fabric

has been developed. In this method, a figured fabric is

woven by a specialty yarn called the ‘chenille yarn’ that a

piled structure appears on each side of the fabric which

cannot be realized on conventional dobby or Jacquard

looms. If this method could be industrialized for mass-

production, the application fields of figured fabric would be

dramatically widened including interior goods and decorative

garments [6]. For this, a CAD software has been developed

which designs the chenille yarn and figured fabric through

the simulation of each weaving process [7]. Also a computerized

loom controller has been developed and attached to a rapier

loom to control its elementary motions including let-off,

shedding, weft insertion, beating, and take-up to handle the

numerous weft insertion sequences [8].

Principles of Plain Weave Figured Fabric

The overview of figured fabric generation method developed

in this study is as shown in Figure 1. First, an image is

prepared of which the number of colors is equal to or less

than the number of selectable wefts in the loom to be used.

In case there are more colors than can be handled by the

loom, the number of colors should be reduced using the

color quantization method. Then the image is subdivided

*Corresponding author: smkim71@jnu.ac.kr Figure 1. Overview of plain weave figured fabric generation.

137

138 Fibers and Polymers 2011, Vol.12, No.1 Sungmin Kim and Joon Seok Lee

into small cells according the approximate diameter of the

weft used. For example, if the diameter of weft is 2 mm, the

image is subdivided into 2×2 mm square cells. Assuming

that each row of the subdivided image is connected to form a

continuous strip, the sequences of colors on that strip can be

regarded as the weft insertion sequences. Then, a woven

yarn sheet can be prepared by inserting appropriate wefts

according to that sequence using a leno structure. Finally, a

specialty yarn called the ‘chenille yarn’ is obtained by

separating each warp of the yarn sheet. A single chenille

yarn makes one repeat unit that a complete figured fabric

can be produced by connecting all the threads together and

weaving it in a plain structure.

Computer Aided Design of Figured Fabric

Color Reduction

In case there are more number of colors in the original

image than can be handled by the loom, the should be

reduced using the algorithm described as follows. First, list

up all the discrete colors in the image and count the

frequency of each color. Then sort the list according to their

frequency in descending order. Finally, calculate the color

difference for every pair of colors in the list and change the

color with the lower frequency into the color with the higher

frequency if two colors are almost similar. By repeating this

process with recounting the frequencies in each step, the

number of colors in the image can be reduced into an

arbitrary number. Color difference between two colors C1

and C2 can be evaluated using equation (1).

(1)

Cdiff: Color difference

CnR,G,B: Red, green, and blue components of nth color

In this study, the number of colors was limited to eight as

the rapier loom used was able to handle up to 8 wefts

automatically. Examples of original and color-reduced

images are as shown in Figure 2.

Cellular Subdivision of Image

To make a good-looking figured fabric from an arbitrary

image, it is very important to define a correct repeat unit. In

this study, a special user interface was designed to extract a

correct repeat unit from the original image as shown in

Figure 3.

To calculate the weft insertion sequence from the repeat

unit, the image was subdivided into small square cells. The

size of a cell can be regarded as the approximate diameter of

weft yarn that figured fabrics of various resolutions can be

generated by changing the cell size. Cell size should be

chosen carefully as it is closely related to the consumption of

weft yarn, fabric production rate, and so on. Examples of

subdivided images are as shown in Figure 4.

Simulation of Woven Yarn Sheet and Figured Fabric

Assuming that each row of subdivided image is connected

altogether to form a long strip, the sequence of colors on that

strip can be regarded as the sequence of weft insertion.

Therefore, a woven yarn sheet can be obtained by inserting

each weft according to that sequence. Each warp in the

fabric is then separated to form chenille yarns. In this

method, yarn sheet should be woven in a leno structure so

that the cut wefts should not be pulled out easily. A single

Cdiff C1R C2R–( )2

C1G C2G–( )2

C1B C2B–( )2

+ +=

Figure 2. Examples of original and color-reduced images; (a)

original images and (b) color-reduced images.

Figure 3. Examples of correct repeat unit definition; (a) incorrect

repeat unit and (b) correct repeat unit.

Plain Weave Figured Fabric Fibers and Polymers 2011, Vol.12, No.1 139

chenille yarn thread makes one repeat unit of the figured

fabric and the simulated result of woven yarn sheet is as

shown in Figure 5.

Once all the weft insertion sequences are calculated, it is

possible to simulate the figured fabric as shown in Figure 6.

In this method, various fabrics with design parameters such

as width, weft diameter, and length can be simulated

instantaneously that it is possible to determine the process

variables for actual fabric production easily.

Approximate amount of weft needed for the formation of

one repeat unit can be calculated using equation (2).

(2)

Rwidth,height: Size of repeat unit

: Average diameter of weft thread

Approximate amount of weft needed for the formation of

final figured fabric is calculated using equation (3)

(3)

Fwidth,length: Size of figured fabric

CRweft: Crimp factor of weft

Wselvage: Length of selvage weft

Assuming that t is the time needed for one weft insertion,

total time needed for the generation of woven yarn sheet can

be calculated using equation (4).

(4)

Wrepeat

Rwidth

Cell size--------------------

Rheight

Cell size--------------------× Dweft×=

Dweft

Wfabric Wrepeat

Fwidth Flength×Rwidth Rheight×------------------------------×

1

CRweft

--------------×=

Wselvage 2×Rheight

Cell size--------------------×+

Total timeFwidth Fheight×

Cell size( )2------------------------------

Wselvage 2×Cell size

------------------------+⎝ ⎠⎛ ⎞

t×=

Figure 4. Examples of subdivided images.

Figure 5. Simulation of woven yarn sheet formation.

Figure 6. Examples of repeat units and corresponding simulated

figured fabrics.

140 Fibers and Polymers 2011, Vol.12, No.1 Sungmin Kim and Joon Seok Lee

Development of Computerized Loom Controller

Computerized Loom Controller

As described above, several thousands of wefts should be

inserted in a perfect order to form a piece of woven yarn

sheet. It was impossible to do this manually that a computer

controller was developed to control the weft insertion

motion of the loom directly according to the sequential data

output from the CAD software. The loom used in this study

was a rigid rapier loom, of which the lef-off and take-up

motions were controlled by two servo motors while the

shedding, weft insertion, and beating motions were controlled

by pneumatic force. As the weft insertion motion should be

completely synchronized with other motions, the controller

was designed to be able to control all the elementary

motions of the loom. All the motions except the let-off and

take-up motions are controlled by solenoid valves which

regulate the flow of compressed air. Therefore each motion

can be controlled by regulating the working current of

respective solenoid valve using an SSR (solid state relay).

The controller developed in this study consists of two

LabJack U12 data acquisition system as shown in Figure 8.

There are 32 digital communication channels and each

channel controls 20 harnesses, 8 weft selector, body, and

rapier respectively. Also there are two 5-phase stepping motor

drivers which can precisely control the let-off and take-up

motions to enable the adaptive regulation of weft density.

Modification of Rapier Loom

Some modifications were made on the loom to accommodate

to the controller and to facilitate the formation of woven

yarn sheet. As mentioned above, the yarn sheet is woven in

leno structure. However, the pneumatic power of the loom

was not sufficient for leno harnesses that additional

apparatus consists of several springs was attached to each

harness to ensure the clear shedding motion. The servo

motors were replaced by 5-phase stepping motors to keep

the let-off and take-up motions perfectly synchronized with

the beating motion. As a single weft insertion failure can

result in a serious fault in the final figured fabric, a CCD

camera based weft detection system was developed in this

study. Once a weft is inserted, CCD camera checks whether

the weft is inserted correctly or not by real time image

analysis algorithm as shown in Figure 8.

Formation of Woven Yarn Sheet and Figured Fabric

An example of woven yarn sheet is as shown in Figure 9.

To verify the fabrication method developed in this study, a

relatively simple image was used. A woven yarn sheet was

cut into individual warps threads and each thread was

connected one after the other manually to form a continuous

weft thread. It was finally woven into a figured fabric on a

commercial rapier loom as shown in Figure 10.

Although some processes were done manually including

the cutting of yarn sheet and final weaving, it was sufficient

to verify the performance of CAD software developed in this

study. As the research on the automation of cutting and

weaving process is going on, it would be possible to produce

figured fabric automatically in the near future.

Figure 7. Overview of computerized loom controller.

Figure 8. CCD camera based weft detection system; (a) CCD

camera and (b) image processing for weft detection.

Plain Weave Figured Fabric Fibers and Polymers 2011, Vol.12, No.1 141

Conclusion

In this study, a new fabrication method of plain weave

figured fabric has been developed. A CAD system has been

developed to analyze the target image and generate

corresponding weft insertion sequence. Also a computerized

rapier loom controller has been developed to make woven

yarn sheet in a leno structure by inserting numerous wefts in

a perfect order. Then each warp of the yarn sheet was

separated into a single chenille yarn. Each yarn was then

connected into a weft thread and woven into a figured fabric

in plain structure. The fabric woven by this method shows

the same figure on both sides unlike those fabrics woven on

dobby or Jacquard looms. It also has a uniform pile structure

on both sides which is not pulled out easily. In fact, it is still

very difficult to automate the cutting of the woven yarn

sheet, and the precise insertion of each woven yarn for the

accurate representation of original figure is somewhat tricky.

However, if those processes could be automated through

continued research, it would be possible to mass-produce the

high quality figured fabric which could be used widely not

only for garments but also for various industrial products.

References

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2. M. Yates, “Fabrics: A Guide for Interior Designers and

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3. M. Humphries, “Fabric Reference”, Prentice-Hall, New

Jersey, 2003.

4. K. Lee, “Principles of CAD/CAM/CAE”, Addison Wesley,

Massachusetts, 1999.

5. A. Ormerod and W. Sondhelm, “Weaving Technology and

Operations”, Hyperion Books, New York, 1995.

6. S. Meller and J. Elffers, “Textile Designs”, Harry and

Abrams, New York, 1991.

7. S. Alderman, “Mastering Weave Structures”, Interweave

Press, Connecticut, 2004.

8. Y. Koren, “Computer Control of Manufacturing Systems”,

Mcgraw-Hill, New York, 1983.

Figure 9. Example of woven yarn sheet.

Figure 10. Example of figured fabric.