Weaving - Flow chart of Weaving

FLOW CHART OF WEAVING Yarn In the form of spinner’s package Warp Preparation Weft Preparation Winding cone, cheese Winding Cop, Pirn, Cone, Cheese Warping Pre beam/ Warper’s be

Class lectures Module

Southeast University

Department Of Textile Engineering

TEXTILE

A Textile was originally a woven fabric but now the term textile and its

plural textiles are also applied to fibers, filaments, yarn and most product for which these are a principle raw material, the product includes threads, cords, ropes, braids, woven, knitted, non-woven fabrics, nets, household textile, geo-textile, medical textiles etc

WEAVING

Weaving is the action of producing fabric by the interlacing of warp and weft thread The warp threads are placed along the length of the fabric and the weft threads are placed along the width of the fabric

FLOW CHART OF WEAVING

Yarn

(In the form of spinner’s package)

Warp Preparation Weft Preparation

Winding (cone, cheese) Winding (Cop, Pirn,

Cone, Cheese)

Warping (Pre beam/ Warper’s

beam/ back beam) Weaving (Fabric)

Sizing (weavers beam)

Drafting, Drawing, Pinning

Denting, Looming

Weaving (Fabric)

Geo-Textile: Embankment

Medical Textile: Non-alginate fabric

Three types of yarn package are mention bellow

Cone Flange bobbin Cheese

TYPES OF FABRICS

1 Woven fabric (Shirt)

2 Knitted fabric (T-shirt)

3 Non-woven fabric (Tea pack)

4 Special fabric (Fire proof fabric, water proof fabric)

OBJECTS OF YARN PREPARATION

1 To remove yarn faults ( there are 23 types of yarn faults)

2 To transfer the yarn from spinner package to a convent form of

package which will facilitate weaving.

3 To have desired length on a package

4 To clean the yarn for better appearance and performance

5 To make good quality fabric

6 To reduce labor cost

Intentional Unintentional

FAULTS TO BE REMOVED DURING YARN-PREPARATION

QUALITY OF GOOD WARP

1 The yarn must be uniform, clean and free from knots as much as possible

2 The yarn must be sufficient strong with withstand the stress and

friction without end breakage

3 Knots should be a standard size and type So that they can pass the heald eye, dropper, read easily

4 The warp must be uniformly sized and size coating should be thick enough to protect the yarn various function

5 The ends of warp must be parallel and each must be wound onto a weavers beam at an even and equal tension

6 All warp yarn should of same size in length

TYPES OF PACKAGE

TYPES OF PACKAGE WINDING

There are three types of package winding available

1 Parallel wound package

2 Near parallel wound package

3 Cross wound package

Parallel Wound Package Features

• Much yarn can be wound at a time.

• No need of traversing motion.

• Side withdrawal is possible

• The density of yarn is more.

• No change of twist/inch

• For yarn unwinding separate mechanism is needed.

• Two side of the package needed flange.

Near Parallel Wound Package Features

1 No need flanged here

2 Both side and overend withdrawal is possible

3 Twist/inch can be changed

4 Traversing motion is needed

Cross-Wound Package Features

1 Here no flanged is required

2 Traversing mechanism is must

3 Twist/inch changes

4 Only overend withdrawal is possible

5 Yarn ballooning occurs during

unwinding

6 This package is very stable

PACKAGE DRIVING

TYPES OF PACKAGE DRIVING

There are three types of package driving system

1 surface contact driving (indirect system)

2 direct driving at constant angular speed

3 Direct Driving At Variable Angular Speed

1 SURFACE CONTACT DRIVING (INDIRECT SYSTEM)

In this system, the yarn package is placed with a surface contact of a drum The drum is driven by a motor and same gear When it rotates the package also rotate is reverse direction

2 DIRECT DRIVING AT CONSTANT ANGULAR SPEED

In this system the package is placed on a spindle and spindle gets motion by a motor and some gears So, that package gets a constant angular speed Here yarn take up rate is directly proportional to the package dia

3 DIRECT DRIVING AT VARIABLE ANGULAR SPEED

In the system yarn package is directly driven at a variable angular speed to give a constant yarn speed Here the package speed is inversely proportional to the package radius,

I.e Package speed 1

Package radius

The appearance of the curved path of running yarn during unwinding or over end withdrawn from packages under appropriate winding condition through a guide, placed above and in line with the axis of the package at an adequate distance from it, the yarn assumes the appearance of a balloon shape This circumstance of assuming balloon shape of yarn is called ballooning

FACTORS EFFECTING THE SHAPE AND SIZE OF BALLOON

1 Package size Ballooning

2 Yarn guide distance Ballooning

3 Lift the package Ballooning

4 Count of yarn Ballooning

5 Air resistance Ballooning

6 Unwinding rate Ballooning

YARN WITHDRAWAL OR UNWINDING

The unwinding process of yarn from a package is called yarn withdrawal There are two types of yarn withdrawal system:

1 Side Withdrawal

2 Overend Withdrawal

1) Side Withdrawal

The features of side withdrawl of yarn are given bellow;

a Package will rotate in side withdrawal

b Yarn twist will be unchanged

c No formation of balloon occurs

d It is applied to flanged bobbin

e The rate and speed of unwinding is slow

2 Overend Withdrawal

The features of overend withdrawl are given bellow;

a Package remains stationary during unwinding

b Formation of balloon occurs

c Twist/inch of yarn changed

d Generally cop, pirn, cone, chess are packages used for overend withdrawl

e The rate of unwinding is high

YARN GUIDE

In winding and unwinding some small component control yarn path which is

very necessary, yarn guide is used to perform this job

TYPES OF YARN GUIDE

There are two types of yarn guide

1 Yarn Guide For The Yarn Whose Ends Are Required For Threading;

For this type of yarn guide extra time is needed for threading So speed of

operation is decreased The yarn which passes this guide faces more

friction

Like Ceramic, Tumpet, Bust

2 Yarn Guide For The Yarn Whose Ends Are Not Required For

TENSION DEVICE

During winding, we have to impart proper tension to yarn, so that we can get a stable and undamaged package So we pass the yarn through a device called tension device

Types of Tension Device

There are four types of tension device as follow;

a) Capstan Tensioner

b) Additive Tensioner

c) Combined Tensioner

d) Automatic Tensioner

B ADDITIVE TENSIONER

This is also a simple technique of applying tension of yarn In this device a dead weight or spring is used in the middle of the two surfaces in contact and the force is applied to give suitable tension to the yarn Hence the output tension is expressed by,

C COMBINED TENSIONER

It is the combined form of additive and capstan tensioner The device permits the tension level to be raised to any desired level, but doesn’t permit a reduction of tension Here output tension is expressed of follow:

D AUTOMATIC TENSIONER

It is a simple tensioner in which yarn tension is controlled automatically It has a lever with spring loaded disc in one side and applied load in another side The device is designed in such a way that if applied tension is too high The pressure on disc is reduced to bring the tension back to its proper level

EFFECT OF TENSIONING DEVICE

There are some effects of tension to yarn or package: They are

a) If tension is too high

b) If tension is too low

• Weak the thin place

b) If Tension Is Too Low

• Irregularity among yarn

Auxiliary Function in Winding

• Creeling

• Piecing

• Doffing

CHOICE OF TENSIONING DEVICE

• It must be reliable

• It must be easily threaded

• It must neither introduce nor mainly tension variation

• It must not change the twist of yarn

• It must not be affected by wear

• It must be easily adjustable

• It must not be affected by the presence of oil and dirt

• It must not encourage the collection of dirt and lint

• It must be easy cleaning

• The operating surface must be smooth

• It must be cheap

• It must not cause any type of damage to yarn i.e shade variation, elongation yarn breakage

PRECISION WINDING FEATURES

• Packages are wound with reciprocting traverse

• Package contains more yarn

• Low stability of package

• Hard and more compact package

• Low unwinding rate

• The wound coil are arranged parallely or near parallely

FEATURES OF NON-PRECESSION WINDING

• Coils are cross wound

• Package is of low density

• Less amount of yarn is stored in package

• High stability of package can be obtained

• Flange is not necessary

• Unwinding rate is very high

1 lb of yarn contain = 24X840 yds yarn

500 lbs of yarn contains = (24X840X500) yds yarn

560 yds of yarn to wind in 1 drum needs =1 min

1 yd “ “ “ 15 drum “ =1/ (560X15) min

(24X840X500) yd “ “ 15 drum = (24X840X500) / (560X15) min

=1200 min

=20 hr.(ans.)

1 lb of yarn contains = 25X840 yd yarns

500 lb of yarn contains = (25X840X900) yd yarns

600 yds of yarn to wind in 1 min in = 1 drum

1 yd ’’ ’’ ’’ (60X28) min in = 1 / (600X60X28) drum

(25X840X900) yds ’’ (60X28) min = (25X840X900) / (600X28X600) drum

= 18.75 drum

= 19 drum (ans.)

2 Warping should not impair the physical and

mechanical properties of yarn.

3 The surface of warping package must be cylindrical.

4 A pre-determined length of yarn should be wound on beam from every package.

5 The production rate of warping is as high as possible.

6 If possible, yarn faults should be removed

TYPES OF WARPING

Mainly there are two types of warping,

a) Direct/ high speed warping

A) DIRECT/HIGH SPEED WARPING

High speed warping is a process of preparing warp beam directly from yarn package Here all the yarns are wound on a simple flange beam at a time This process is suitable for single color pattern

FEATURES OF SECTIONAL WARPING

• Sectional warping is suitable for producing color fabrics with different pattern

• Production in sectional warping So it is costly process

• In sectional warping tension cannot be kept uniform

• Tapered drum is used as drum here

• Hand weaving is necessary to produce for simple fabric for bulk production

FEATURES OF HIGH SPEED WARPING

• High speed warping is suitable for producing fabric with same count & same color yarn

• Higher amount of yarn is required here

• The speed & production of a high speed warping is very high

• Here simple flanged

Control System in Warping

• Surface speed control

• Proper yarn density

• Static electricity

• Traverse control

• Fly control

Faults in Warping

• Off center warp

• Rigid or uneven warp

Relation between Taper Angle and Amount of Yarn on a Beam

Let, s = traverse length.

L = axial

d = empty beam dia.

D = full beam dia.

dm =

= mean dia.

X = tape distance

α = taper angle

v = volume of yarn stored on beam.

Let, s >x so as to maintain stability.

V =

- = ( - ) = πL ( ) ( )

So, v = π L dm (x tanα)

V > π L dm S tan α if, x > s

V < π L dm S tan α if, x < s

So, V S tan α if α = 90° then V = α

So unlimited amount of yarns can be wound if flange stays perpendicular to beam barrel Practically this is impossible But this type of package permit’s to wind high amount of yarn.

From figure, it is clear that

dm = = x tan α

• To improve breaking strength of cellulosic yarn.

• To increase yarn smoothness

• To reduce yarn hairness

• To increase yarn elasticity and stiffness

• To decrease yarn extensibility

• To hinder generation of static electricity for synthetic and blended yarn

• To increase yarn weight

Sizing Ingredients and Their Functions

Some important size ingradients and their functions are mentioned

below-1 Adhesive

2 Lubricants or softeners

3 Antiseptic or antimildew agent

4 Deliquescent or Hygroscopic agent

5 Weighting agent

6 Anti-foaming agent

7 Tinting agent

8 Wetting agent

TECHNOLOGICAL CHANGES OCCURE DUE TO SIZING

The following technological changes of a yarn/fabric occurs due to sizing –

1 INCREASE IN BREAKING STRENGTH

2 INCREASE ABRASION RESISTANCE

3 INCREASE IN STIFFNESS

4 INCREASE IN ELASTICITY

5 INCREASE IN FRICTIONAL RISISTANCE

6 INCREASE IN YARN DIAMETER

7 DECREASE IN YARN HAIRINESS

8 DECREASE IN STATIC ELECTRICITY FORMATION

Size Take Up Take Up Percentage Depends On The Following Factors

• Twist

• Yarn count

• Viscosity of size material

• Speed of yarn passing through m/c

• Pressure of squeezing roller

• Amorphousness of fiber in yarn

• Flexibility of yarn

• Nature of adhesive

• Time and temperature

SIZE TAKE-UP PERCENTAGE

Size take up % =

Wt of size material o yarn × 100

Wt of unsized yarn

Twist S.T

Yarn count S.T

Viscosity of size material S.T

speed of yarn passing through m/c S.T

Pressure of squeezing roller S.T

Amorphousness of fiber in yarn

S.T

Flexibility of yarn S.T

Nature of adhesive S.T

Time and Temperature S.T

Size Take up Percentage Depends on the Following Factors

SIZE CALCULATION

MATH-1: A beam of wt 290 lbs contains 3500 sized warp of 1300 yds length It

the unsized yarn count is 28 Ne and empty beam wt 70 lbs., then calculate

-1 Wt of size on yarn.

2 Count of sized yarn.

3 Size take-up percentage.

The loom is the contact point of the whole process of cloth production, ginning, opening, carding, spinning, winding, warping, sizing and beaming are done before weaving A loom cannot be said a machine but it is a device which is used to produce woven fabric Looms are generally driven either by line shaft or by individual motors fitted with it

Weaving Mechanism / Basic Principle of Weaving

Weaving is the process of interlacement between the warp and weft in fabric according to a design of fabric

Basic principle or weaving mechanism is:

• The yarn from the weavers beam passes round the back rest and comes forward through the drop wire of the warp stop motion to the heald eye of heald shaft which

is responsible for the purpose of shade formation

• It then passes through the dent of reed which holds the thread at uniform spacing and it is also performed the beating up the weft thread that has been left in the triangle warp sheet form by the two warp sheet and reed

• In this way, weft yarn is meshes with last pick of fabric or cloth Temple holds the cloth firm at the feed position and assist in the formation of a uniform fabric width Then fabric passes over the front rest, take up roller, pressure roller and finally wind

on to the cloth roller

The mechanism of a power loom receives their motion from shaft that traverses from side to side in the loom and is driver from another Their relative speeds are of importance since they give the mechanism that they drive.

The crank shaft being driven by the motor moves one revolution per picks The motion of the teeth of the gear wheels connecting this shaft to the bottom shaft is always 2:1, so that the bottom shaft will move one revolution in ever two picks