INTRODUCTION TO WEAVING PROCESS

INTRODUCTION TO
WEAVING PROCESS

SOMASHANA PRAKASAM
AHMAD AZLAN AHMAD

JABATAN KEJURUTERAAN
MEKANIKAL
POLITEKNIK SEBERANG PERAI

INTRODUCTION
TO WEAVING
PROCESS

Somashana Prakasam
Ahmad Azlan Ahmad

2021
Jabatan Kejuruteraan Mekanikal

©All rights reserved. No part of this publication may be translated or reproduced in
any retrieval system, or transmitted in any form or by any means, electronic,
mechanical, recording, or otherwise, without prior permission in writing from
Politeknik Seberang Perai.

ii PSP eBook | Introduction to Weaving Process

All rights reserved

No part of this publication may be translated or reproduced in any retrieval system,
or transmitted in any form or by any means, electronic, mechanical, recording, or

otherwise, without prior permission in writing from Politeknik Seberang Perai.

Published by

Politeknik Seberang Perai
Jalan Permatang Pauh, 13500 Permatang Pauh

Pulau Pinang

Tel : 04-538 3322 Fax : 04-538 9266
Email: [email protected] Website : www.psp.edu.my
FB : politeknikseberangperai Ig : politeknikseberangperai

Perpustakaan Negara Malaysia Cataloguing-in-Publication Data

Somashana Prakasam, 1981-
INTRODUCTION TO WEAVING PROCESS / SOMASHANA A/L PRAKASAM,
AHMAD AZLAN BIN AHMAD.

Mode of access: Internet
eISBN 978-967-0783-92-5
1. Weaving.
2. Textile fabrics.
3. Textured yarn machinery.
4. Government publications--Malaysia.
5. Electronic books.
I. Title.
746.14

PSP eBook | Introduction to Weaving Process iii

Acknowledgement

Grateful to God in completing the academic writing for the production eBook for
students to learn weaving topic in fabric technology course. In this opportunity, my
sincere thank you to the head of Mechanical Department Politeknik Seberang Perai in
providing tutoring and guidance to complete this eBook. Special acknowledgement
goes to my work colleagues for the support and cooperation for completing this eBook.

Somashana A/L Prakasam
Ahmad Azlan Bin Ahmad

iv PSP eBook | Introduction to Weaving Process

Preface

This Introduction to The Weaving Process eBook has been provided for Mechanical
Engineering Department Textile student. This topic emphasizes on the preparation of
weaving process in fabric manufacturing.
The knowledge of weaving process is essential part of fabric manufacturing in
industries. This eBook elaborates the process involved yarn preparation in sizing and
warping, operation of woven structure, process of drawing in and tying in, and
explanation of basic weaving principles. Besides, it describes the function of dobby
mechanism and jacquard system.

PSP eBook | Introduction to Weaving Process v

Table of Content Pages
Chapter
1
CHAPTER 1: YARN PREPARATION 12

1.1 Allocate the operation of warping machine
1.2 Allocate the operation of sizing machine

CHAPTER 2: WEAVING 23
31
2.1 Assign the operation of woven structure 33
2.2 Assign the process of drawing-in and tying-in 38
2.3 Explain the basic weaving principle 39
2.4 Detail the functions of cam 42
2.5 Allocate the functions of dobby mechanism
2.6 Allocate the functions of jacquard

References vi



1CHAPTER PSP eBook | Introduction to Weaving Process 1

YARN PREPARATION

1.1 Allocate the operation of warping machine

A fabric is made up of fibrous materials that might be natural or man-made. Nowadays, there
is a variety of technologies that may be used to manufacture textiles, all of which are referred
to as fabrics.
Natural fibres such as cotton, flax, and hemp, as well as animal sources like as wool, hair, and
silk, were used to make all cloth in the past. Artificial fibres such as polyester and rayon were
added in the twentieth century to augment these natural fibres.
Yarn is “a generic name for a continuous string of textile fibres, filaments, or material in a
form suitable for knitting, weaving, or otherwise interweaving to make a textile fabric in a
form suitable for knitting, weaving, or otherwise intertwining to produce a textile fabric. Yarns
play a significant part in the fabric manufacturing process because yarns make up the majority
of textile materials.
Yarns come in a variety of sizes and textures, as well as other qualities. The yarn qualities have
an impact on performance, end use, and fabric maintenance.
The real yarn composite utilised in the cone winding operation cannot be used for the beam.
Before it can be used, it must first be converted into a beam.

Figure 1.1 Natural fibres

2 PSP eBook | Introduction to Weaving Process

Warp Preparation

Figure 1.2 Warp preparation flow chart
Definition of Warping
Warping is the process of transferring or altering a spinner’s package to a weaver’s beam that
is suited for weaving.

Figure 1.3 Warping Process

PSP eBook | Introduction to Weaving Process 3

Objective of Warping
The purpose of warping procedure is to turn yarn packages into a warper’s beam with the
necessary width and number of ends.

Figure 1.4 Warp beam
The industrial warping process can be carried out in two ways, depending on the type of
intermediate carrier used which is :

i. Beam warping / Direct warping
ii. Sectional warping / Indirect warping

Figure 1.5 Type of warping method

4 PSP eBook | Introduction to Weaving Process

Beam Warping (Direct Warping)
It is used for single-colour (Grey fabric) / Simple pattern. Cones and cheese of the same colour
and size are hung on a creel. It is then combined with winding to create a warper’s beam. For
lengthy runs of grey fabrics, beam warping is used.
The process of joining yarns from different packages to generate a sheet of warp threads on
a warpers beam is known as direct warping. A warpers beam has fewer warp threads, and
these warpers beams are merged to produce a single weavers beam during the size process.

Cone Beam

Figure 1.6 Direct warping

In the following situations, direct warping is used:
1. Large order volume
2. Yarns that are not coloured
3. Simple warp patterns made with coloured yarns in huge quantities

Figure 1.7 Schematic diagram of direct warping

Sectional Warping (Indirect warping)
Sectional warping is used for shot runs, especially for fancy patterned fabrics.
Shot runs, especially for fancy patterned fabrics, involve sectional warping. To create the real
pattern, cones of various colours and sizes are arranged at the creel.

PSP eBook | Introduction to Weaving Process 5

Cone Beam Beam
Figure 1.7 Indirect warping

In the following situations, sectional warping is used:
• Limited quantity orders
• Yarns with dyes
• Complex warp patterns
• Yarns that are delicate

Figure 1.8 Block Diagram for Sequence of Sectional Warping

Figure 1.9 Sectional Warping Machine

6 PSP eBook | Introduction to Weaving Process

Components of Warping Machine
A warping machine has three major components:
1. Creel
2. Headstock
3. Control device

Table 1.1 Creel parts and functions Function
Creel parts
To avoid yarn slack throughout the
Tension device manufacturing process
Controlling yarn winding tension from cone to
Overrun prevention device beam
Automatic stop motion To prevent sloughing-off, act automatically when
the yarn breaks or the machine stops.
Suction fan When the sensor detects a yarn break, the
machine will automatically stop.
When the cone is empty
To eliminate dirt and dust from yarn

Figure 1.10 Cone Placements in creel

PSP eBook | Introduction to Weaving Process 7

Beaming Headstock
It is used to wind and arrange the yarn on the beam. The headstock consists of two small
guide rollers and the main draw (drag) roller, as well as a unit to support weaver’s beams of
various widths, make up this unit. Given below are the functions of beaming headstock parts.

Table 1.2 functions of beaming headstock parts

Beaming headstock parts Function

Adjustable Comb /Zig-zag comb To ensure that the warp arrangement from the creel

is the same distance as the width of the beam flange.

This will prevent interlacing by ensuring that the

yarns wind parallel to one another.

Measuring roller When the roll reaches the required length, the

machine should immediately stop.

Presser roller Controlling the density of the beam’s windings

To make faults on the beam, such as sank and sink,

easier to detect and prevent.

Motor To generate cycle movement to the drum in order for

the machine to operate.

8 PSP eBook | Introduction to Weaving Process

Beaming Calculation

1. If warp amounted to 3780 ends wish to be produced, of which creel abilities are

900 packages. Calculate the number of beams.

Beam Number (Number Of Beam)

= End number (Number of Thread)
Creel Capacity (Creel Capacity)

= 3780
900

= 4.2

≈ 5 beam

2. An order has been given received for 220 sheets of woven fabric. Each sheets have 110
mm length and 1.2 m width. Count the total of beam and actual length of warp yarn
needed if :
warp crimp = 9%
fabric density = 38 ends / cm
creel capacity = 500 cones
selvedges are ignored

Total No. of End = Fabric density x fabric width
= 38 end / cm x 120cm
= 4560 end

No of Warp beam = Total No. of end / creel capacity
= 4560 / 500
= 9.12
= ≈ 10 beam

Fraction End for each beam = Total No. of end / No of warp beam
= 4560 /10
= 456 end

PSP eBook | Introduction to Weaving Process 9

Total length warp yarn needed = Total piece x length piece x (100 +Crimp/100
= 220 x 110 m x 109/100
= 26378 m

3. An order has been received for 350 sheets of woven fabric. Each sheet is 120 m length
and 1.2 m width. Calculate the total beam and actual length of warp yarn needed if :
warp crimp = 9%
fabric density = 38 ends / cm
creel capacity = 500 cones
selvedges are ignored

Total No. of End
= Fabric density x fabric width
= 38 end / cm x 120cm
= 4560 end

No of Warp beam = Total No. of end / creel capacity
= 4560 / 440
= 10.36
= ≈ 11 beam

Fraction Ends for each beam
= Total No. of end / No of warp beam
= 4560
= 4560 / 11
= 414 end

Total length warp yarn needed
= Total piece x length piece x (100 + Crimp / 100)
= 350 x 120 m x 109/100
= 45780 m

10 PSP eBook | Introduction to Weaving Process

Factors That Determine The Quality of Warp Yarn
• The yarn thickness must be consistent, clean, and tangle-free.
• Yarns must be strong enough to withstand the strain (stress) and friction encountered

during the weaving process.
• To improve the flow of movement during the weaving of yarns, the size and kind of knot

should be consistent.
• The content size (solution size) must be sufficient to protect the yarns from friction during

the weaving process while also preventing the surface of the pile yarn from being
damaged.
• During the process of winding up the beam, the warp yarn composition must be parallel
to each other, and the stress conditions (tension) must be consistent (warping)

Effective Weaving Characteristics of a Good Warp
• Strong
• Uniform
• Smooth
• Knot-free
• Slub-free
• Withstands abrasion of moving loom parts
• Withstands cyclic strains and stresses of loom

Conclusion
The process of winding warp yarn from a cone to a warp beam is known as warping.
To roll uniformly and compactly, the warp yarn arrangement in the beam must be parallel to
one another and have the same tension.
Warp beam calculations were necessary to avoid warp yarn distribution errors in beams that
were compliant with client orders and the machine’s capabilities.

PSP eBook | Introduction to Weaving Process 11

1.2 Allocate the operation of sizing machine

Explain the function and operation of the sizing machine
Sizing is the process of applying a sizing solution to the warp yarn to prevent thread damage
or breakage during the weaving process. A single unsized yarn cannot endure the stresses of
weaving, which has an impact on loom productivity and efficiency. As a result, sizing the yarn,
particularly the single yarn, becomes critical. It is, in fact, the most crucial step in the weaving
preparation process.

Purpose of Sizing
• To increase the warp yarn’s weaving ability
• Reduce hairiness, frailty, and increase smoothness and absorbency of yarn to preserve

good fabric quality
• The yarn’s tensile or breaking strength is improved
• The yarn’s elasticity is improved
• The weight of the yarn is enhanced
• To make the frictional resistance higher
• To minimise the production of electrostatic
• Increase the yarn’s abrasion resistance

Important Sizing Technical Considerations
• The following are the most important aspects to make:
• The type of weaving machinery that will be utilised to weave the sized yarn
• The amount of tension applied to the yarn is determined by the type of loom. The forces

experienced in weaving affect different fabrics (cotton, polyester, etc.)
• The sort of sizing material used is determined on the type of textile material. During the

process, the yarn is subjected to various pressures and strains.

12 PSP eBook | Introduction to Weaving Process

Sizing Process Description
Yarn sizing is done by passing the warp yarn sheet through a size box holding the sizing
chemical that has been pre-prepared. In the sow box, the warp sheet is passed through
tension rollers, immersion rollers, size rollers, and squeezing rollers, in that order.
The yarn sheet is then placed in drying cylinders heated by steam, where the water is
evaporated from the yarn surface and the sizing chemical creates a film. The yarn sheet is
next passed through the post waxing roller, which coats the sizing chemical layer with
additional lubricants to control hairiness and simplify weaving.
The warp sheet is separated after drying and waxed so that the yarns regain their distinct
character before being wound on the weaver’s beam.
Because warp sheets coming out of the drying area stick to each other depending on the
efficiency of the pre-drying section, splitting is required.
The warp sheet is divided in a systematic manner by chromium coated lease rods, separating
the yarns that are stuck together by dry size.
The warp sheet is eventually wound on the weaver’s beam after splitting. The warp sheet is
fed through an adjustable reed that can be expanded or contracted depending on the beam
width.

Warp Sizing Machine

Figure 1.11 Main Parts of a Sizing Machine

PSP eBook | Introduction to Weaving Process 13

Figure 1.12 Process Flow of Sizing
Sizing Machine
The sizing machine is a large machine used in the textile industry. It might be more than 100
feet long with a 50-foot height. The components of the machine are as follows:
Creel
Sizing box
Section for drying
Splitting section/leasing rod
Winding section
Flow process of sizing machine

Figure 1.12 Flow process of sizing machine

14 PSP eBook | Introduction to Weaving Process

Warpers beam Creel
Creel’s Purpose
• Mounting of beam
• Unwinding of warp sheets
• Combining of warp sheets

Creel is a crucial component of the sizing machine. The beams of the warper are attached to
the creel. The creel’s beam mounting capacity is determined by the total number of ends in
the weaver’s beam. Each beam nips between two rollers as it turns. The rollers can move
around freely.

Size Boxes
To prevent corrosion, the size box and all pieces that come into touch with the size solution
are made of stainless steel. From the bottom up, the size box has a curved shape with no
sharp edges. Steam is generally used to heat the size liquor in the size box, which is provided
through a steam coil at the bottom of the size box.

Parameters controlled in the size box
• Level of size solution
• Temperature
• Yarn speed
• Squeeze roller pressure
• Concentration of size liquor

PSP eBook | Introduction to Weaving Process 15

Figure 1.13 Size Box Used For Sizing Process
Immersion roller (A)
To direct the warp yarn into the size solution.The distance between the two points can be
adjusted according to the requirements, which will affect the size solution’s penetration.
Squeeze roller (B/B’)
To press the size solution into the warp yarn by using sizing rollersBy regulating the pressure
applied to the yarn, the amount of sizing solution that penetrates equally into the yarn can
be controlled.
Sizing roller (C,C’)
Assists the insertion of solution into the yarn size by working in tandem with the squeezing
roller.
Float roller (D)
When the size was reduced, an automatic size solution was provided. As a result, these can
regulate the amount of size solution in the size box to keep it constant.The yarn’s size pick-up
will be affected by an inconsistent level of solution.
Steam heating pipe €
To maintain the temperature of the solution at a constant level. Inconsistent temperatures
will cause the viscosity of the size solution to change.

16 PSP eBook | Introduction to Weaving Process

Sizing ingredients

Water
Assist in the sizing of materials.

Adhesive agent
Used to strengthen the fiber bond in thread act as a main ingredient (starch).

Wax
After the material has gone through the glue process, the thread is smoothed and
softened.It’s critical to keep the material size from coming off during the weaving process, as
this might lead to thread breakage. Typically, wax is in the form of fat. Tallow is the most
commonly utilised material (animal fat)

Preservative agent
Preservative materials such as zinc choride and carboxymethyl cellulose are used to protect
yarn from bacterial attack.

Deformer
To remove the foam from in size solution.

Anti sticking agent
To avoid yarn sticking at machine components

Anti static agent
During weaving, it avoids the development of electrostatic charge in the warp yarn. When the
warp moves up and down during weaving, the ends scrape against each other, causing an
electrostatic charge to build up in the warp. During weaving, these electrostatic charges cause
warp breakage.

PSP eBook | Introduction to Weaving Process 17

Carboxymenthyl Celulose

Figure 1.14 Types Of Adhesive Agents
The function of size ingredients
Adhesive
• To increase the strength of yarn
• To improve the smoothness of yarn
• To improve the elasticity and stiffness of yarn
• Reduce the percentage of extensions in yarn
Wax / Lubricant / Softener
• To make the yarn soft & slippery
• To make the yarn smooth
• To alleviate stiffness
• Flexibility and friction are reduced.

18 PSP eBook | Introduction to Weaving Process

Drying In Sizing
The wrap sheet is impregnated with wet size paste to the amount of 90 percent to 140 percent
of its own weight after leaving the size box. The process of drying involves complete removal
of the moisture from the size paste and at the same time retaining the water in the yarn.
In sizing, there are three important drying procedures. These are the following:
• Conduction method
• Convection method, and
• Radiation method

Multi-Cylinder Drying
This is the most often used method in industry. The number of drying cylinders utilised in this
situation ranges from 5 to 13. The cylinders are significantly smaller than those utilised in the
convectional twin-cylinder machine. One of the advantages of the multi-cylinder is that the
cylinders are positively powered, which avoids the yarn from being under too much tension.
Because the cylinders are mounted on ball bearings, they rotate smoothly. A separate steam
supply valve is provided for each cylinder. The temperature of each drying cylinder can be
adjusted individually to fit the type of yarn and the machine. The temperature of each cylinder
is controlled by a number of factors, including the type of yarn used, the device’s speed, the
number of cylinders, and so on.

Figure 1.15 Cylinder dryer with hood

PSP eBook | Introduction to Weaving Process 19

The factors of a good drying
1. The cylinder’s surface temperature.
2. The amount of time yarn is exposed to the cylinder drying surface. An excessively dry

environment can lead yarn to become brittle and easily broken. The under dry process
will cause yarn easily infected with fungus when rolled-up at the beam.
3. The machine speed should be compatible with the drying rate and cylinder count. The
faster speed setting can cause under drying. Over drying can occur at lower speed.
Leasing
The lease rods in the splitting zone are used to separate individual yarns that have been
entangled due to the drying of the size film in the drying section.This has the effect of
preventing it from sticking between two layers.

Figure 1.16 Expanding comb / wraith / open reed / zig zag comb
Headstock
The weaver’s beam and the associated drive gears are supported by the head stock, which is
a take-up unit.

20 PSP eBook | Introduction to Weaving Process

Figure 1.17 Type of roller
1. Measuring Roller (A) A roller is used to measure the length of the warp yarn.
2. Tension Roller (also known as a drag roller) (B)When the warp yarn is drawn from the

drying cylinder to the weavers beam / size beam, maintain the proper tension and
uniformity (constant).
3. The press roller (C) applies pressure to the weavers' beam in order to compress the
winding yarn (hydraulic press).
4. Weavers beam (D) To wind the warp on the beam surface and maintain a steady winding
pace. Otherwise, as the beam diameter grows, the yarn will break owing to changes in the
surface.

2CHAPTER PSP eBook | Introduction to Weaving Process 21

WEAVING

2.1 Assign the operation of woven structure

Weaving is one of the oldest methods of manufacturing cloth, and it is frequently used.
Examples of weaving products are table clothes, draperies, upholstery, denim, quilts, and
curtains.

Construction of woven fabrics
Weaving is the process of interlacing two strands of yarn at right angles to each other. Warps
are the lengthwise threads, and ends are the individual threads. Filling or weft refers to the
crossing threads, whereas picking refers to each individual thread. Weaving is done on a loom,
which allows the warp and filler threads to be interlaced in a pre-determined pattern. The
fabric’s lengthwise edges are known as selvages. Weaving is used to make woven fabrics.
Example of end uses for woven fabric is apparel fabric such as suits, dresses, coats, and shorts.
It also can be used to produce towel, curtains, table clothes and bedsheets.

Figure 2.1 Image of warp and weft direction

Woven structures for fabric consist of two categories:
i. Basic woven structure
ii. Complex woven structure

22 PSP eBook | Introduction to Weaving Process

Table 2.1 Categories of fabric woven structure

Basic Woven Structure Complex Woven Structure

Consist of two set of yarn which Consist of two or more set yarn

intersect to produce flat surface which intersect to produce texture

surface

For example: plain, twill, satin, and For example: leno, dobby, jacquard,

sateen pile woven and

double woven

Conventional & Modern woven method
Basically, both these methods have similar operation. The difference is the insertion method
of the weft yarn.

Table 2.2 Difference between conventional and modern loom

Conventional Method Modern Method

Shuttle being used as a mechanism to Weft yarn being inserted using air jet
insert weft yarn mechanism, water jet, projectile, rapier
and multiple shed where these systems
Examples of conventional loom are have high velocity of operation
shuttle loom and hand loom. Examples of modern loom are air jet
loom, rapier loom, projectile loom, and
Lower productivity and design water jet loom.
possibilities Higher productivity and design
possibilities

PSP eBook | Introduction to Weaving Process 23

Definition of warp, weft, and crimp

Warp (ends)
The warp is a set of yarn that is wound vertically around the loom and stays in place during
the weaving process. It gives the weaved fabric its structure. When the woven piece is
finished, the warp is removed from the loom. The warp yarn will go through sizing process
before weaving process, to increase the strength and able to withstand the abrasion and
tension during weaving process

Weft (filling)
The yarns used to weave horizontally through the warp are called the weft. Weft yarn is
supplied from the machine in form of cone.

Figure 2.2 Diagram of warp and weft yarn

Crimp
It is the shrinking process in warp and weft direction which will leads to the dimensional
changes where it will influence the actual distance produced. Crimp factor will be higher in
weft direction as compared to warp direction.

Types of weave design
The way the warp and weft threads are interwoven determines the cloth weave or design.
The most popular weaves are simple weaves with small repeats. Plain weave, twill, and satin
are three basic weaves that have significant variances.

24 PSP eBook | Introduction to Weaving Process

Plain Weave
The plain weave is the simplest and most frequent of the weaves. It is made up of one over
and one under interlacing warp and filler yarn (weft) yarns. When compared to other weaves,
it has the maximum quantity of interlacing and hence provides the firmest fabric. Because the
design is so simple, the weaving procedure is relatively inexpensive. It is strong and hard-
wearing, used for fashion and furnishing fabrics.

Figure 2.3 Flat view of Plain Weave
Twill weave
Twill is the most durable of all weaves. Twill will is characterized by diagonal lines.
Few wrinkles and creases are visible. Because of the material's thickness, twill cloth does not
wrinkle readily. It also shows few stains. The direction of pattern helps hide dirt and stains
from view, so spills at home or on clothes are disguised more easily.

Figure 2.4 Flat view of Twill Weave

PSP eBook | Introduction to Weaving Process 25

Satin Weave
Satin weave fabrics are characterized by luster due to the long floats that cover the surface.
The satin weave produces a lustrous, silky, and elastic fabric with a lovely drape. Satin fabric
has one side with a silky, glossy surface and the other side with a duller surface.
Satin Fabrics Characteristics
Shiny front
Due to the order of the warp and weft threads, satin weaves produce a fabric with a gleaming,
silky right side and a dull back. Satin has a silky, sumptuous feel to it.
Beautiful drape
Satin weaves offer a soft and easy drape due to the concentration of threads and the pliability
of the fabric, making them perfect for evening clothing and curtains.
Durable
Satin is stronger than many plain weave textiles because it is made of long filament threads
that are knitted in a highly taut manner.
Wrinkle-resistant
Satin is less likely to wrinkle than other textiles, and thicker satins are less likely to wrinkle.

Figure 2.5 Flat view of satin Weave

26 PSP eBook | Introduction to Weaving Process

Sateen weave
Fabric with a weft-faced construction is known as sateen. The front is smooth, while the back
is rugged and dense. Twisted threads give a sateen fabric its sheen; the more tightly the yarn
is twisted, the brighter the sheen. It contains more weft floats.

Difference between Sateen and satin
Satin is a warp face weave with a higher number of warp floats, whereas Sateen is a weft face
weave with a higher number of weft floats. These are used in combination with other weaves
for ornamented fabrics.

Table 2.3 Characteristics of sateen and satin fabric

Characteristics Sateen Satin

Weave structure Weft faced Warp faced

Type of fibre Short-staple Filament

Raw materials Cotton, linen, etc. Silk, nylon, rayon,
polyester

Texture Less glossy, softer Glossy, slippery

Sheen Dull Lustrous

PSP eBook | Introduction to Weaving Process 27

Sateen weave characteristics
Breathability
Cotton sateen garments keep the body at a comfortable temperature.
Durability
It retains its original colour for a long time and looks fantastic even after several machine
washes, whether printed or solid.
Glossy surface
It has a smooth and silky front side that is nearly indistinguishable from real silk and satin.
Hypoallergenicity
Satin, which is made of natural cotton, does not induce allergic responses.
Wrinkle resistance
The fabric is extremely drapable and produces soft folds.

Figure 2.6 Flat view of sateen weave

28 PSP eBook | Introduction to Weaving Process

2.2 Assign the process of drawing-in and tying-in

Drawing-in
After the weaver's beam has been prepared, the drawing-in process begins. Sectional warping
or sizing is used to create the weaver's beam. Drawing in is a process of inserting warp yarn
into drop wire, heddle eye (harness) and reed dent, to produce the required fabric design.

Purpose of drawing in
It is used for drawing each warp yarn through drop wires, healds and reed. Given below are
its functions :

Drop Wires / Dropper
A drop wire is a narrow metal sheet that that is hung in the air by the tensioned warp yarn. If
the warp yarn is broken or slacken, then the drop wire drops and touches a metal bar that
extend along the width of the machine. This contact between the drop wire and metal bar
closes an electrical circuit and shuts down the machine immediately. There is drop wire for
each warp yarn.

Heedle eye / Healds
After passing the drop wire, the warp yarn goes through the heddle eye (there is only one
warp yarn per heddle eye). It is used to shed warp yarn and making design.

Reed
The opening between two dents (metal) in a reed is known as a reed gap. One, two, or three
warp yarns are passed through one reed area in general. The number of yarns used is
determined by the diameter of the yarns and the size of the dent hole; each yarn should be
able to travel freely in the reed space without interfering with the other yarns.

PSP eBook | Introduction to Weaving Process 29

Figure 2.7 Drawing in process flow
Tying-in
It is a process to join the warp yarn by tying it at weaving machine when the warp yarn is
finished and need to be replaced with a new beam.
It can be done in manual (conventional) or using automatic machine (modern).
The weaving machine must be stopped during the tying-in phase, which discontinues the
weaving process.

Figure 2.8 Flow Process For Drawing-in And Tying-in

30 PSP eBook | Introduction to Weaving Process

2.3 Explain the basic weaving principle

Weaving process is done on a machine called a loom.
The basic loom operations are divided into three movements which is:
• Primary movement
• Secondary movement
• Auxiliary movement

Figure 2.9 Diagram Of Loom
Primary movement
The primary motion consists of three operations which are:
a. Shedding mechanism (done using tappet, dobby, and jacquard)
b. Picking mechanism (with shuttle/shuttle-less)
c. Beat-up mechanism (By crank/cam

PSP eBook | Introduction to Weaving Process 31

Figure 2.10 Material Passage Through Different Parts Of Loom
Shedding Mechanism
The shedding mechanism divides the warp threads into two layers or divisions, forming a
‘shed' tunnel.
Picking mechanism
The picking mechanism uses a shuttle, a projectile, a rapier, a needle, an air-jet, or a waterjet
to transport weft thread from one selvedge of the fabric to the other through the shed. Pick
refers to the inserted weft thread.
Beat-up mechanism
At the "fall of the cloth," the beat-up mechanism beats or pushes the newly inserted length
of weft thread (pick) into the already woven fabric. These three mechanisms, shedding,
picking, and finally beat-up, are carried out in order.

32 PSP eBook | Introduction to Weaving Process

Figure 2.11 Primary movement in weaving
Secondary movement
These processes are secondary to the fundamental mechanisms in importance. These
mechanisms are necessary for continuous weaving. As a result, they are referred to as
"secondary" mechanisms. They are given below:
a. Take-up motion
b. Let-off motion.
Take-up motion
The take-up motion pulls the cloth away from the weaving area at a steady rate to achieve
the specified pick-spacing (in picks per inch or picks per centimetre) before winding it onto a
cloth roller.
Let-off motion
By unwinding the warp from the weaver's beam, the let-off motion transfers it to the weaving
region at the proper rate and tension. The secondary motions are carried out at the same
time.

PSP eBook | Introduction to Weaving Process 33

Auxiliary Movement
Additional mechanisms, known as auxiliary mechanisms, are added to a plain power loom to
achieve high production and superior fabric quality. The auxiliary mechanisms are helpful, but
they aren't essential. Given below are some of the mechanisms:

a. Warp protector mechanism
b. Weft stop motion
c. Temples
d. Brake
e. Warp stop motion

Warp protector mechanism
If the shuttle becomes trapped between the top and bottom layers of the shed, the warp
protector mechanism will halt the loom. Thus, significant damage to the warp threads, reed
wires, and shuttle is avoided.

Weft stop motion
The weft stop action is used to bring the loom to a halt when a weft thread breaks. This motion
helps to prevent fabric cracks.

Temples
The temples' job is to grip the cloth and hold it at the same width as the warp in the reed
before it is taken up.

Brake
When the brake is applied, the loom is immediately stopped. It is used by the weaver to bring
the loom to a halt so that broken ends and picks can be repaired.

Warp stop motion
The warp stops motion's goal is to bring the loom to a complete halt when a warp thread
breaks during the weaving process.

34 PSP eBook | Introduction to Weaving Process

Weaving machine movement mechanism

The types of shedding mechanisms are referred to as machine movement mechanisms. The
range of fabrics that can be manufactured is determined by the shedding mechanisms used.
The common shedding mechanism used are:
• Tappet shedding
• Dobby shedding
• Jacquard shedding

Table 2.4 Difference of Tappet, Dobby & Jacquard Shedding Mechanism

Topic Tappet shedding Dobby shedding Jacquard shedding

Design capacity Simplest structure Medium Very complex
complex structure structure

No. of Heald shaft Maximum no. of Theoretically it can Theoretically it can
heald shaft – 14. control maximum control any no. of
Theoretically it can 48, but practically
control 6-10 Heald for wool no. of heald warp thread
individually
shafts shaft -36 & for
cotton no. of Heald

shaft -24

Speed of loom Very high High Slow

Driver position of Below the loom Above the loom Above the loom
heald shaft
For different designs For different For different
Design different tappets are designs, different designs, different
design of pegging designed pinched
Cost of fabric fitted to bottom legs is placed on cards are places on
Production rate shaft cylinder/pattern
cylinder
Low fabric cost drum
Expensive Highly expensive
More than the
dobby Less production Less production

PSP eBook | Introduction to Weaving Process 35

2.4 Details of the functions of cam

Cams are classified according to the direction of displacement of the follower with respect to
the axis or oscillation of the cam. The two most common kinds are disc or radial cams. In
these, the cam's working surface is designed so that the follower reciprocates or oscillates in
a plane perpendicular to the cam's axis (see examples c, d, e, f below). Cylindrical cams - These
are commonly employed in machine tools, and the cam causes the follower to oscillate or
reciprocate in a plane parallel to the cam's axis (see examples g and h below).

Figure 2.12 Cam movements
Functions of cam
The Heald shaft motion is operated by cams. The cam's job is to transform the rotational
action of the weaving machine's main shaft into reciprocating motion of the heald frames.
The shape of the cam is determined by its own motion, the follower's needed motion, and
the shape of the follower's contact face.
A new cam pattern requires the following parameters:
1. Design cams – Only suitable for particular jobs
2. No. of cams – Each cam can only control one heald shaft.

36 PSP eBook | Introduction to Weaving Process

3. Transmission ratio of the rotary motion between the main shaft and the cam shaft – It
depends on the number of picks in the lifting plan.

4. The relative position of cams in the set – It depends on the type of weave.

2.5 Allocate the functions of dobby mechanism

Dobby Mechanism can control a large number of heald frames, therefore suitable for weaving
wide range of fabrics. Dobby like cam has positive and negative movements. Dobby
mechanism is used in the shedding process in weaving. It is convenient to do a pattern change.
Unlimited picks per repeat also can be used.

Differences of positive and negative dobbies
Dobby mechanism are classified as negative and positive dobbies, they can be operated
mechanically or using electronic dobby. In negative dobby shedding, the harnesses are lifted
by the dobby and lowered by a spring reversing motion. In positive dobby, the dobby is raised
and lowered by the shaft. Depending on their performance they are divided into single-lift
and double lift dobbies.

Figure 2.5 Difference between positive and negative dobby Negative Dobby
Positive Dobby

Operated at higher speed Operated at lower speed

Most popular Less popular

Movement of heald frame can be Movement of heald frame is controlled
controlled by dobby by dobby and reverse motion spring
Suitable to weave heavy fabric and
technical cloth Suitable to weave medium to fine fabric

PSP eBook | Introduction to Weaving Process 37

Mechanism of dobby
The driving mechanism
It is used to operate knives and has a regular reciprocating action.
The selection mechanism
It's controlled by a dobby card. It reads or verifies the design information punched on a dobby
card and transmits the required movement from the drive mechanism to the lifting
mechanism.
The lifting mechanism
It operates the heald shaft motion.

Figure 2.13 Dobby mechanism

38 PSP eBook | Introduction to Weaving Process

Climax Dobby
When the bottom shaft rotates, the L-shaped crank attached to it turns as well. The lower
end of the connecting rod is attached to an L-shaped crank, while the upper end is attached
to a T-shaped lever. The T form lever makes a reciprocating action on the bottom shaft when
the L shape crank rotates. With the help of a ratchet wheel and a powl, the pattern cylinder
revolves. The one end of the feeler rises up slightly as the pegs installed in the leg get under
the feeler. At the same moment, the other end of the feeler descends slightly. Because the
lower ends of the upper and lower needles sit on these feelers, if the peg presses one end of
the feelers, the needles will also move downward. Because the hooks are resting on their
respective needles, the hook will fall over the knife as the needle descends. Through a
reciprocating motion of the T lever, the knife pulls the fallen hook on the right-hand side. The
jack levers connected with S shape levers are pulled by the other end of the hooks. Now the
heald shaft goes upward. The spiral spring helps to bring down the heald shaft.

Figure 2.14 Climax negative dobby shedding mechanism

PSP eBook | Introduction to Weaving Process 39

2.6 Allocate the functions of jacquard

Jacquard is a "figure weaving" technique. It can be used to create elaborate designs and
detailed images of objects such as flowers and birds to manage the lifting and lowering of the
warp yarn, there is no need for a heald frame. It is capable of weaving figured and complicated
fabrics. Examples of fabric weave using jacquard system are terry towel, masks, leno’s, and
carpet

Advantage of using jacquard system
• The design complexity is limited only by the machine's width
• There is no requirement for a heald frame in draw-in process
• Because no heald frame is used, there is no group lifting of warp yarn
• Individually regulated warp yarn
• Low tension on warp yarn during shedding
• Save time when changing patterns because electronic jacquard may be done on the

machine

Jacquard shedding mechanism
Here, punched card is employed for the jacquard shedding mechanism, which is
manufactured according to design. For each pick, one pattern card is used. These pattern
cards are used to create a pattern chain that is then placed on the pattern cylinder. Each pick
pattern cylinder rotates in a clockwise direction for 1/4 of a full revolution. It oscillates to and
forth at the same moment, making an arc. The movement of each warp yarn is done
individually. Every 1/4th revolution, a new card appears in front of the cylinder on the hook
side, and the needles enter the punch card's holes for the two-and-a-half movement. This
entrance selection inside the needle punches is genuinely done according to design. When a
needle is inserted into the card's hole, it remains stationary in its position. As a result, the
needle crank remains in the same position. As a result, the hooks move upward with the warp
threads to make the top line as the knife moves upward. After a specific amount of time, the
knife releases two hooks, which are elevated to form the top line, and the heald eye comes
down owing to wrap tension and dead weight. The grid bar controls its downward movement.

40 PSP eBook | Introduction to Weaving Process

Each needle contains a right-hand spring that pushes the needle back when the next card is
comes.

1. Hooks
2. Knife
3. Knife frame
4. Neck cord
5. Rod
6. Grade
7. Horizontal needle
8. Needle broad
9. Cylinder
10. Spring box
11. Spring
12. Card

Figure 2.15 Parts of jacquard shedding



vi PSP eBook | Introduction to Weaving Process

References

Kadolph, S. J(2016). Textiles. 12th Edition. Pearson Education.
Adanur, S. (2019). Handbook of weaving. CRC Press.
Banerjee, P. K. (2014). Principles of Fabric Formation. CRC Press.

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