internship at alok industries vapi

1. OBJECTIVES OF TEXTILE INTERNSHIP

The objective of the textile internship includes the coverage of the following given

departments:-

Spun yarn production

Grey fabric production (both woven and knits)

Dyeing process

Printing process

Quality control and testing (testing procedures, quality parameters and various

defects and their control)

Textile Internship at Alok Industries, Vapi, Gujarat

Alok industries Company profile

2.1 INTRODUCTION

Alok industries Ltd is one of India’s largest Vertically Integrated Textile Company. It

is head quartered in Mumbai with its manufacturing units in Vapi,Silvassa & Navi

Mumbai. The company is an end to end provider of Integrated textile solutions with

five core divisions :- Cotton yarn, Apparel fabrics, Home textiles ,Garment and

Polyestor yarns.


FIG:- ALOK INDUSTRIES PRODUCT WHEEL

2.2 HISTORY & EVOLUTION

Alok industries was established in 1986 as a

private limited company, with it’s first polyester

text rising plant being set up in 1989. It became a

public limited company in 1993.

Over the years, it has expanded into weaving,

knitting, processing, home textiles and garments

and to ensure quality and cost efficiencies they have integrated backward into cotton

spinning and manufacturing partially oriented yarn through the continuous

polymerization route. It also provides embroidered products through Grabal Alok

Impex Ltd., their associate company which is the main reason for their evolution into

a diversified manufacturer of world-class home textiles, garments, apparel fabrics

and polyester yarns, selling directly to manufacturers, exporters, importers, retailers

and to some of the world’s top brands. Alok has recently entered the domestic retail

segment through a wholly owned subsidiary, Alok Retail India Limited, with a chain

of stores named ‘H&A’ that offer garments and home textiles at attractive price

points.

2.3 VISION OF THE ORGANIZATION

“To be the world's best- integrated textile solutions enterprise with leadership

position across products and markets, exceeding customer & stakeholder

expectation”.


2.4 MISSION OF THE ORGANIZATION The company aims at achieving the following objectives:

Offer innovative, customized and value added services to customers.

Actively explore potential markets & products.

Optimize use of all resources

Maximize people development initiatives

Become a process driven organization

Be a knowledge leader and an innovator in the businesses

Exceed compliances and global quality standards

Be an ethical, transparent and responsible global organization

2.5 REMARKABLE MILESTONES


YEAR MILESTONE1986 Incorporation of the Company

1993 Becomes a public limited company with a Rs. 4.5 crore IPO

2003 Export Trading House status granted

2006 Texprocil silver trophy awarded for second highest export in manufacturer

exporter – made ups category

2007 ISO 9001:2000 certification obtained

Gold Trophy for best export performance to ‘Focus LAC’ countries

awarded by Synthetic & Rayon Textile Export Promotion Council

Awarded Silver trophy for highest fabric exports and Bronze trophy for

highest made ups export

2008 Awards from TEXPROCIL for 2007-2008

Gold Trophy for highest exports of bleached/yarn dyed/ printed

fabrics.

Silver Trophy for highest export of made ups

Bronze Trophy for highest global exports


Buyer’s requirement: - Requirements and specifications required are sent

4. PROCESS FLOWS

4.1 PROCESS FLOW AT NARROW WIDTH PLANT(WOVEN, KNITS , YARN)


Prod. Development and Lab dip : - development of swatches of the shade sent by the buyer

samples are developed as per spec. and sent for buyer’s approval.

Buyer comments- The buyer approval or comments for some changes. If some changes are

asked for then the samples are re-developed and sent again

Pre-Production sampling: - The Product development department develops nearly 100 –200

pieces in the approved shade. Out of these adequate pieces are sent to the buyer.

Production Planning: - As per the sales order the PPC makes the production plan along with

the material requirement plan.

Sales order: - The sales order is prepared and given to the PPC department of the plant

through the plant merchandiser

Purchase order: - The buyer sends the bulk order in the form of purchase order.

Buyer’s approval: - The buyer’s approval of the piece which meets his standards and this

sample serves as the standard towel for reference between the buyer and the manufacturer.


Processing order:- Production order is given to the preparatory and dyeing departments.

Processing: - Processing and finishing takes place as per the processing plan.

Folding and inspection:- inspection takes place of the processed good which then packaged

Final Q.A: The final Q.A takes places before packaging and dispatch to assure quality of goods

Shipment :- The goods are dispatched.

Material procurement:- A purchase order is generated for the required dye ,chemicals and

other required raw materials to the suppliers

4.2 PROCESS FLOW AT TERRY TOWELS PROCESSING PLANT


Buyer’s requirement: - At first the buyer sends his requirement for towel according to feel, look

and absorbency. He also specifies the towel design and dimensions.

Material procurement:- A purchase order is generated for the required dye ,chemicals and

other required raw materials to the suppliers

Production Planning: - As per the sales order the PPC makes the production plan along with

the material requirement plan.

Sales order: - The sales order is prepared and given to the PPC department of the plant

through the plant merchandiser

Purchase order: - The buyer sends the bulk order in the form of purchase order.

Prod. Development and Lab dip : - development of swatches of the shade sent by the buyer

samples are developed as per spec. and sent for buyer’s approval.

Buyer comments- The buyer approval or comments for some changes. If some changes are

asked for then the samples are re-developed and sent again

Pre-Production sampling: - The Product development department develops nearly 100 –200

pieces in the approved shade. Out of these adequate pieces are sent to the buyer.

Buyer’s approval: - The buyer’s approval of the piece which meets his standards and this

sample serves as the standard towel for reference between the buyer and the manufacturer.


Processing order:- Production order is given to the preparatory and weaving departments.

Processing: - Weaving and finishing takes place as per the processing plan.

Folding and inspection:- inspection takes place of the processed good which then packaged

Final Q.A: The final Q.A takes places before packaging and dispatch to assure quality of goods

Shipment :- The goods are dispatched.

Cut & Sew and Packaging:- Stitching and packaging takes plan as per the cut & sew plan.

PART II

Weaving (Terry

weaving)


1. WEAVING (TERRY WEAVING)

1.1 Introduction

The weaving department forms the core of fabric production in a textile industry. In

this department our study concerns about the weaving of terry towels i.e. uncut pile

weaving. The weaving department has following sub departments in it:

Textile design department

Weaving preparatory department

Weaving department

Grey folding department


1.2 PROCESS FLOW FOR TERRY WEAVING


WAXING/SIZING WAXING/SIZING

YARNYARN

DYED YARNDYED YARN GREY YARN

GREY YARN

SECTIONAL WARPING

SECTIONAL WARPING

DIRECT WARPINGDIRECT WARPING

SIZING SIZING

WEAVING WEAVING

GREYGREY

PROCESSSING PROCESSSING

MADE UPSMADE UPS

1.3 TEXTILE / WEAVING DESIGN DEPARTMENT

The objective of this department is to prepare a pattern for the weaving process to

achieve the desired effect and look on the fabric as per the buyer‟s specification.

The department receives the specifications from the marketing dept after which

sampling is done and samples are sent for approval, approved designs then go

further for production.

The department performs the following works:-

1. Designing of the product

2. Analysis & feasibility of product

3. Preparation of bill of materials required for preparing the product

The various Qualities or types of towels developed are:-

Piece dyed towels(grey towels)

Yarn dyed towels

Yarn dyed and grey velour towels(cut pile)

Yarn dyed and grey partial velour towels(partial cut pile)

Cad software’s used for weave design developments are:-

Textronics design dobby for development of dobby designs

Net graphics texcelle for developing jacquard designs


1.4 LAYOUT OF THE TOWEL

The basic structure of towel is divided into these main parts:

1. Plain: - A tightly woven strip mainly a twill /any compact weave.

2. Hem: - A Strip woven for the purpose of folding and stitching the hem

3. Terry bar: - A terry bar is a short width terry weave dividing the hem and the

border.

4. Border: - A strip woven for the purpose of providing aesthetic appeal and may be

woven as per buyer specification.

5. Body: - The body contains the main terry part that consists of pile loops all over.

6. Selvedge:- selvedge is the right and left borders of the towel which are generally

woven in leno weaves


HEMHEM

TERRY BARTERRY BAR

BORDERBORDER

BODYBODY

BORDERBORDER

TERRY BARTERRY BAR

HEMHEM

PLAINPLAIN

PLAINPLAIN

WARPING PLANWARPING PLAN

WARPINGWARPING

SIZINGSIZING

TRANSPORT WEAVERS BEAM TO WEAVING DEPT TRANSPORT WEAVERS BEAM TO WEAVING DEPT

1.5 WEAVING PREPARATORY DEPARTMENT

In the weaving preparatory mainly warping and sizing is done for the purpose

assistance in the the weaving process. The yarn requirements are determined as per

the design and then warping is done first

1.5.1 PROCESS FLOW OF WEAVING DEPARTMENT

1.5.2 WARPING

There are 2 warping machines of which there is a direct warping machine from

benninger with a creel capacity of 640 creels and another sectional warping

machine from Prashant gamatex with a creel capacity of 680 creels.

Before warping plan is made following things have to be considered:

Cone length


DESIGNING

Beam capacity

Required length

1.5.2.1 DIRECT WARPING

The cones are placed on the creels and the ends are passed through two pre

stationary rods out of which one is stationary and one is movable. These rods

are responsible to give proper tension to the yarns. There is also an auto ply

tension unit with light indicator to control tension during running and stops the

machine The yarns are passed through a zig-zag yarn guide(dents) to the gear-

controlled cylindrical beam which continuously rotates and prepares the warping

beam. There is also a display at the front of the operator which indicates the

breakage cone row and column number.

Presser roller which is in contact with the warp beam ensures uniformity in

formation of the warp beam and in cylindrical form. Singles yarns are preferred

for direct warping, as they are to be sized in the successive process.


Fig :-Benninger direct warping m/c

Technical details of the machine

Beam capacity 1250 kg (60000 m)

Warping speed 20 to 1200 m/min

Beam length 2400 cm

Creel capacity 640

Yarn tension 610 dN

Max count range 13s- 16s

These warpers beam from the direct warping machines are converted to weavers

beam while sizing

1.5.2.2 SECTIONAL WARPING

Sectional warping is done in some versatile intricate and majorly yarn dyed pieces

where the consumption of different warp yarns is different depending on the design

of the towel. The drum roller intermittently winds the yarns from creels and the beam

automatically moves laterally to get a uniformly wound section beam as per the data

fed according to the required design. This section warper’s beam is then waxed by a

winding roller in a continuous manner which successively gets wound on to the

weaver’s beam. Double yarns are preferable to be sectional warped. The leasing

and section reeds are used to separate different coloured yarns and determine

number of yarns in a dent respectively. Sectionally warped beams do not require

sizing hence these are directly converted into weavers beam, then the warper’s

beams are carried by the trolleys to the sizing department


Features of sectional

warping machine(manufacture –Prashant Gamatex)

Separate Warping & Beaming Structure.

Optical device for precise Sectional width measurement & setting

Optical device for precise Sectional width measurement & setting

Constant beaming tension.

Constant warping and beaming speed.

1.5.3 SIZING

The sizing process aims at providing extra strength to the warp yarns for

withstanding tension and abrasion during weaving. There are 2 sizing machines of

Benniger and west point. Sizes like Terry size are used which contain starch based

or synthetic like polyvinyl alcohol or a water soluble acrylic polymer, depending on

the fiber content of warp yarns.

1.5.3.1 Benninger sizing machine (Ben –sizetec)


Fig:- Prashant Gamatex Sectional Warping

Fig:- Benninger Sizing Machine

The sizing section of the weaving department has 2 sizing machines with 12 creels

for the warpers beam(zone1). The warped beams are put on the creels and all the

warp ends are passed through various cylinders without any inter-yarn entanglement

and messing up of yarns.They are passed into a bath of a water base sizing

solution.The bath has a temperature of 90oC which has two nip rollers and two dip

rollers which guide the yarn for proper sizing through proper bathing.The yarns have

a continuous movement through the solution as they travel through the drying

cylinders which have a temperature of 140oC, 130 oC, 125 oC, and 110 oC in the

respective cylinders in the drying chambers (ZONE 2 AND 3). Leasing region is the

dry region from where the yarns get separated by dividing rods to avoid yarn

grouping which could create difficulties in weaving. Thus by the automatically

monitored and controlled system, the yarns are wound on the weaver’s beam. These

weavers’ beams are transferred to the looms.

Technical details :-

Speed of sizing 90-100mts /min

Temperature in the bath 950c

Tension in input yarn 650 N

Tension in output yarn 1050N

No. of creels 12

No. of drying cylinders 12

Temperature 37 0 c

Relative humidity 68 %


1.5.3.2 WEST POINT SIZING MACHINE

The west point sizing machine has the

same operational process as that of

Benninger sizing machine. The machine

is used as an alternative to the Benninger

sizing machine.

Technical specification

Beam

Creel

Maximum No.

of Beams

Section Beam

Flange

Diameter

30

800 mm/1000 mm/1250 mm

Size

Box

No. of Boxes

Sizing system 1

Single dip - Single nip or

Double dip - Double nip


Fig :- BEN-SIZETEC

Fig: - WARPERS BEAM CREEL

Dryer No. of

Cylinders

up to 24 drying Cylinders.

Predryer in the multiples of 4 to 6,

and final Dryer having 4/6 or 8

cylinders

Beam

Winder Working width

Beam flange

diameter

Max. Yarn

Speed

Carriage

Tension

1800 mm to 4000 mm

up to 1250 mm

150 Meters per minute

Both side motorised

Auto Control


Fig:- SIZING BATH

1.6 WEAVING


PLANT LAYOUT WEAVING DEPT.

JACQUARD M/C

JACQUARD M/C

JACQUARD M/C

FU

TU

RE

EX

PA

NS

ION

DOBBY M/C

DOBBY M/C

DOBBY M/C

DOBBY M/C

DOBBY M/C

EXIT

EXIT

EXIT

DOBBY M/C

FUTURE EXPANSION

PIPE BEAMTROLLEY-2

1.6.1 INTRODUCTION

After the sizing process of the pile and the ground beams, they are manually

transported to the weaving looms. All the looms present in the weaving department

are Toyota air jet looms. According to the production plan looms are allotted for

specific towel weaving. The beams of the pile & ground are gaited on to the loom as

specified in the loom plan and design plan. The design through floppy/ programmer

is set on the looms. The loom process control parameters for the functioning of the

beams are set, like the reed, the pick, the terry motion, let off, take up etc & weaving

starts.


Pile beamPile beam

Ground beam

Ground beam

Tension rodTension rod

Dobby shedding healds

Dobby shedding healds

ReedReed

Temple rod Temple rod

Fabric rollerFabric roller

Tension rollerTension roller

1.6.2 WEAVING MACHINERY

1.6.2.1 TOYOTA AIR JET LOOMS

SThere are 36 dobby looms out of which 18 machines are of 20 shafts and other 18

are of 16 shafts..

Technical specifications of Toyota air jet looms

Working width available on the

loom

340 cm

Speed of the machine / Rpm of

machine

450

Type of fabric produced 100% cotton towels

Warp yarn counts usable on loom 2/20s

Weft yarns count usable on loom 12s,14s,16s,20s,2/20s

Weft insertion single electric drum, 2, 4, 6-color

exchange electric drum

Reed count in use 60 “ ,56”,64”

Gsm of fabrics possible for

production

400,500,450,600

Shedding: negative cam, positive cam, crank,

dobby, electric shedding, jacquard

Selvage type possible on loom Left/right rotary full-leno selvage

device.


Fig : TERRY WEAVE MECHANISM WITH DOBBY

There are 12 jacquard looms of which 6 are regular jacquard looms with jacquard

attachments ( stabouli LX1602 ) and other 6 are jumbo jacquards with jacquard

attachments (stabouli LX 3202). The LX 1602 and LX 3202 electronic Jacquard

machines are particularly suitable for weaving flat fabrics and terry cloth on all types

of air jet looms, 2688 hooks are present in LX 1602 attachments to while 8192

hooks are present in LX 3202.In regular jaquards the 3 hooks are controlled by a

single knife while in a jumbo jacquard for every hook there’s a knife..These

jacquards are easily adaptable and versatile in nature. These jacquards minimize

threads stress and Precise lifting mechanism with no vibration.


Fig:- AIR-JET LOOM WITH JAQUARD

Fig:- LX 1602 Jacquard

Fig:- LX 3202 Jacquard

1.6.3 WEAVING MECHANISM

Firstly the weavers beam is loaded into the loom. Then the yarns from the

weavers beam are knotted to yarn ends left after the previous weaving process.

Knotting process saves time required for drawing yarns one by one from heed

frame and reed. It usually takes 20 to 25 minutes to load a weavers beam and

get the loom started for repetition of old designs.

Drawing in

Here 16/20 heald dobby attachments are used for terry towel designing. The pile

threads are drawn on four healds, & the ground threads (if the loop formation is to

be continuous) on eight healds. 2 healds are used for leno and 2 are used for

selvedge.

Drop pin Mechanism (stop motion)

There are drop pins for every single yarn. Yarn is passed through the whole

provided in the drop pin. Each pin has a bar passing through it such that it does

not touch the pin when yarn is in tension If yarn breakage occurs in any yarn, the

pin drops and it touches the bar and a sensor is activated, which in turn stops the

machine. The yarn is spliced manually.

Shedding

Selected yarns are lifted according to different weave construction to create

space for insertion of weft yarn by different mechanisms which form a basis of

classification of loom.(jacquard/dobby).


Picking

Air jet mechanism is used for picking mechanism.In the formation of the pile loops,

the speed of the pile beam (let off) is more than the speed of the ground

beam.During weaving of the borders of the towel, let off is same for both the beams.

Beating up

The weft thread that has been inserted across the warp thread in a shed is pushed

upon the fell of the cloth. This process is carried out by a reed which is a comb like

structure through gaps of which warp yarns are passed. Two temples are provided at

both the ends. They pull the fabric produced and keep a pre determined tension in

warp yarns. They also assist in take up mechanism.

Let Off

There is a sensor at the torsion roller which regulates the tension of the warp sheet

and also send message to the sensor present in the let off roller so as to decide how

much warp is required to be let off.It allows the warp yarns to move in forward

direction by unwinding weavers beam maintaining a predetermined warp tension.

Take Up

A motor is provided which winds the fabric produced in the loom. Once the cloth

roller for winding of the towel is full the roll is doffed & sent to the Grey folding area.


1.6.4 ADDITIONAL ATTACHMENTS TO THE LOOM

Some other important attachment are as follows :

1. Creel Stand - They are used to yarn cheeses for

weft insertion.

2. Package Sensor - This ensures no loose or miss

pick.

3. Pre Winder - It acts as temporary storage of yarn

and ensures uniform tension of yarn.

4. Weft Break Sensor - These are in contact with the

weft yarn and stop the machine in case of weft yarn

breakage.

5. Auxiliary Nozzle - This nozzle has small openings for air jet inclined in forward

direction which give a forward motion to weft thread. Nozzle is not fixed and moves

with the motion of thread.

6. Main Nozzle - It is fixed nozzle and the working is similar to that of auxiliary

nozzle.

7. Relay Nozzle - These inclined nozzles are provided on the path of the weft yarn.

They provide an air jet which provides a uniform.

motion to the weft yarn towards other end.


Fig :- Weft creel

8. Feelers - There are 2 sensors provided on the right side of the loom. The function

of h1 feeler is to sense the miss pick or sort pick. Function of the filler is to sense the

broken pick or wrong pick. If any of these two sensors are activated, machine stops.

9. Cutter - Two cutters are provided at either ends which cut the extra weft yarns.

10. Tucker - It binds the remaining yarn into the selvedge.

11. Catch cord - It catches and holds the filling yarn.


1.6.5 TERRY WEAVE CONSTRUCTION

The Turkey towel structures form a class of warp pile-termed “terry” pile – in which

certain warp threads form loops or curls on the face of the cloth.

Only one kind of weft may be used, but 2 series of warp threads, placed on separate

beams, are necessary for the production of the cloth- viz. ground threads & pile

threads.

The distinguishing feature of this class of pile is that the looped structure is produced

by employing a special reed motion & warp easing arrangement which enables the

loops to be formed on the upper or lower, or both upper& lower surface of the

cloth,many different kinds of terry motions are used, but in every case the object is to

cause two succeeding picks of wefts to be left a short distance from the fell of the

cloth, & then to beat up these two picks along with the following pick.In weaving the

cloth the ground warp beam is heavily tensioned, so that these threads are held tight

all the time. The picks 1 & 2 are first woven into the proper sheds, but are not beaten

fully up to the fell of the cloth by the slay at the time of insertion in their sheds; but

when the pick no.3 is inserted, the parts are so operated that the three picks are

driven together into the cloth at fell. During the beating up of the third pick the pile

warp threads are either given in slack, or are placed under very slight tension. with

the result that the slack pile warp threads are drawn forward thus forming two


fig:- TERRY WEAVE CONSTRUCTION

horizontal rows of loops of piles, one projecting from the upper & the other from the

lower surface of the cloth.

PART III……

DYEING


Fig:- Continuous Apparel width processing and yarn dyeing plants

1. WOVEN APPAREL WIDTH DYEING

(NARROW WIDTH PROCESSING)

1.1 INTRODUCTION

Dyeing /processing is the most delicate section of the textile industry. Several

parameters are to kept in mind while performing operations. The processing unit in

the beginning receives greige fabric from the either the silvassa plant or other

external sources .this shipment of fabric is received by the greige department which

performs the initial actions before fabric is ready for further processing. Fabrics

processed here in all the machines are of an average width of 48 inches/160 cm.


FIG:- NARROW WIDTH PLANT

1.2 PROCESS FLOW FOR WOVEN PROCESSING

IF COTTON IF NOT COTTON


GREY FABRIC

PRE-TREATMENT RANGE

DYEING

FINISHING

MERCERIZATION

PACKAGING AND INSPECTION

GREY ROLLSGREY ROLLS

GREY ROLL OPENING MACHINE GREY ROLL OPENING MACHINE

A- FRAME BATCH A- FRAME BATCH

CONTINOUS SINGEING AND DESIZING RANGE CONTINOUS SINGEING AND DESIZING RANGE

1.3 GREY ROOM /GREIGE DEPT

The main operations of the grey room include opening up of fabric rolls and

combining them into A-frame batches for assisting continuous processing. These A-

frame batches are used for the purpose of combining many fabric rolls of small meter

age into one continuous roll of maximum capacity of 4500 kg. There are 5 greige

opening machines of local brand (Topiwalla).these machines process the fabric from

the rolls to A-frame at a speed of 150metres/minute.

1.3.1 PROCESS FLOW IN GREY ROOM


1.3.2 GRIEGE FABRIC OPENING

The fabrics are sourced from the silvassa plant from where 95 % of the supply is

received and the other 5% is from external sources.

The product mix available and processed:-

Fabrics by weight:-Light, medium, heavy

Fabrics by blend:- PolyCotton, Cotton Viscose, CottonLycra, Cotton

Spandex

Fabrics By weave:- Twill,Plain,sateen,satin, dobby, design(Jacquard)

The fabrics are also avaible in grades of A, B, C, D which are already graded when

received. 2000 Steel Racks have been provided for storage for upto 29 lakh fabric

rolls. Fabric roll placement style for storage is of cross –layered type .Average

length of fabric on a A-frame batch is 4500 mts Fbric Rolls are opened and

converted into A-frame batches and sent for further processing of singeing and

desizing.

1.3.3 SINGEING AND DESIZING

Singeing is the process of surface hair.Singeing is

done via gas flames

which come in contact

with fibers and burn

them. The fabrics run in

the perpendicular

direction of the gas

flames for singeing.

Singeing and desizing are performed as a combined process in the grey department.

There are 3 machines on which these

operations are performed. All machines

are German (osthoff senge)

manufactured(models:-VP99-H (2 m/c)


Fig: Gas burner

Fig:- Gas Flame

&VP-99(1 m/c).These machines have Processing speeds in range of 60-120

mts/min.

Light fabrics :- 120 mts/min

Heavy fabrics- 60 mts/min

Chemicals used in desizing:-

Wetting agent :- assists increase in absorbency.

Enzymes :- required for removal of sizes applied to fabrics.

Chelating agents :- restricts the reaction of any metal ion with any added

chemicals.

These machines can process up to 30,000 mts /day

The machines have single gas flame chamber with 2 burners, 1 impregnating

chamber for desizing chemical application, a steam box for assisting chemical

activation for desizing ,3 extracta chambers for washing off the chemicals and

delivery customers( steam rollers ) for machine meant for yarn dyed if the fabric is

required in dry condition. The temperature for washing and steam box is 950. Two

methods for desizing :

Hydrolytic desizing: - in this after the chemical application through

impregnation the batches are rotated at a uniform speed for 24 hrs

for desizing agents activation and avoid leaching out of chemicals

from the batch. To perform this type of desizing a single machine is

available which only singes and impregnates the desizing

chemicals

Enzymatic desizing: - In this the chemical activation is done by

rotation in a steam chamber with a required dwelling time required

for chemicals to activate. To perform this type of desizing 2

machines are available which have a steam box for this purpose.


Fig:-Singeing and Desizing (Hydrolytic) range

1.4.1 PRE-TREATMENT RANGE

There are 3 continuous pre-treatment ranges available which perform the above said

preparatory process in a continuously. Fabrics from greige department arrive here

and are fed into the machine. It is a composite machine range where the fabric is

desized, washed, bleached and dried before it is dyed.The entire process takes 25 –

30 minutes to complete. The process flow of the pre-treatment range is as follows:

Feeding

. Fabric from the A-frame trolleys is fed into scray where through the feed roller

whose speed can be controlled separately from the other rollers in the machine. The

Scray acts like a storage device for the fabric roll as it enters the extracta chamber.

This storage device temporarily holds the grey fabric such that rate of feeding the

fabric can be controlled as well as it gives time for the operator to stitch the

upcoming roll to the end of the present fabric without actually stopping the unit.

Washing

The fabric is passed through the 3 washing chambers each with the Benninger

Extracta technology. The main purpose of these washing chambers is to wash away

the extra chemicals from the surface of the fabric. These chambers have the

capacity of holding 180 litres of water respectively. The impure water is continuously

flushed out and is replaced by fresh water such that the level of 180 litres is

maintained in the chambers. The temperature maintained in the first chamber is 950

C and the following two is maintained at a temperature 800 C each. The fabric takes

a total of 3 minutes to pass through these chambers spending 1 minute in each

chamber. The fabric is then passed to the bleaching chamber.

Bleaching

The fabric after passing through the washing chambers is passed on to the Injecta

chamber. Here, the bleaching chemicals like H2O2,Wetting


agent,Stabilizer,Reserver(chelating agents),NaoH are impacted on the cloth woth

high velocity. Sometimes even whitening agents are added to achieve extra

whitness.Here, the bleaching is done through the peroxide method. The fabric is

passed through this chamber and goes into the steam chamber which has the ben-

bleach technology for assisting the bleaching process, at a temperature maintained

at 95o C and 3 bars pressure. The pH of the solution maintained is 13 – 14. The

fabric nearly stays nearly 15 minutes in this chamber before it is passed on the

washing chambers, the chemicals are fed automatically into the chamber from the

storage tank which is stationed beside the machines. Similarly, the water level is also

maintained. These chemicals are supplied to the storage tanks from the colour

kitchen

Washing

From the bleaching chamber the fabric is then passes through 3 washing chambers

which have Benninger Extracta technology.. The main purpose of the washing

chambers is to remove the extra chemicals that accumulate on the surface of the

fabric. The temperature maintained at the first washing is 95oC and the remaining

two maintained at 80o C each. The fabric spends approximately 2 minutes in each

washing chambers. After this the fabric is passed to the neutralizing chamber.

Neutralization

After passing through the washing chambers the fabric is passed on to the

neutralizing chamber which is similar to that of the washing chamber with the only

difference that this chamber is supplied with the neutralizing agent. The neutralizing

agent is used to neutralize the excess peroxide and caustic soda present on the

fabric surface which may hamper the dyeing process later. The fabric takes 2

minutes to pass through this chamber where the temperature maintained is 60oc.

After this the fabric is passed onto the delivery customer.

Drying

The fabric is passed through a series of steam heated delivery customer rollers.

These rollers rotate at a speed of 50 rpm. The rollers are present in two sections of 5

each in each vertical column. They are arranged in such a way that alternatively

rollers rotates in clockwise direction and anti-clockwise direction and the fabric


alternatively passes through these rollers and dried before it finally wound onto a A-

frame roller. The fabric coming out of the pre-treatment range is termed as RFD

( Ready for Dyeing Fabric).

The Average production rate is estimated to be 80-100 mt-min. There are different

machines for light and medium weight fabrics, heavy weight fabrics and limp and

stretchable fabrics, machine suitable for limp fabrics has drums in its washers

instead of rollers for avoiding any type unnecessary expansion or width reduction.


Fig : PRE-TREATMENT RANGE

1.4.2 MERCERIZATION

Mercerization is a preparatory process mainly used for cellulosic fibres when lustre is

important or light shades are to be dyed. Benninger mercerizer with equipped with

the Ben-dimensa technology is used for the mercerization process. There are three

mercerizers out of which 2 machines are based on the chain principle, while the third

machine is of chainless principle exclusively used for heavy/bottom weight fabrics.

The Average processing speed is 60-70

mts/min

Chemicals used in the process for mercerization

are:

NaoH, Organic acid, Caustic soda.


Fig:- MERCERIZER RANGE

Fig:-Impregnation Chamber

The fabric is fed into the machine via the feed rollers and the weft straighteners to

the chains which lead to the impregnating chamber where the NaOH is sprinkled on

the stretched fabric held by chains. The intensive impregnating zone is followed by

the reaction zone. In the retention compartment of the DIMENSA the chainless

principle with lifting top rolls is employed. At the start of the stabilizing zone that is

immediately after the Mercerizing section there is a stenter section using the chain

principle. Ultimate stabilization is done in a conventional, highly effective stabilizing

compartment with chainless guidance. Stabilizer chemical is sprinkled for assisting in

removal of NAOH.

The final section comprises a high-efficiency washing and neutralizing zone

consisting of EXTRACTA, or TRIKOFLEX compartments, where temp maintained is

between 90-95 C and pH-5-6, organic acid is used for neutralization.The final

Mercerized fabric has a pH of 5 and can also be labelled as RFD.


Fig:-Impregnation and Dwelling zone

Fig:- Stabilizing zone

Fig:- Washing and Neutralization

1.5 DYEING

After completion of the pre-treatment processes the batches are marked as RFD

(Ready for Dyeing).The dying process is decided by the dye used, preferred fixation

process and quality desired. The prominent dyes used for the dyeing are reactive,

disperse and vat

1.5.1 PROCESS FLOW FOR DYEING


Fig:- Washing and Neutralization

PURE COTTON FABRIC :-

BLENDED POLYCOT DOUBLE BATH PROCESS


PRE-TREATED FABRIC (cotton )

Cold pad Pad dry padding

Continuous dyeing

Colour development Pad steaming for

curing

Dyed

Pre-treated (Polycott Reactive dyeing in CDR

Reduction clearing on pad Disperse dyeing in CDR

Washing

BLENDED FABRICS POLYCOT SINGLE BATH PROCESS

1.5.2 COLD PAD BATCH


Reduction clearing on Washing on washing /soaper

Dyeing is single bath solution of

reactive as well as disperse dyes

on CDR

Pre-treated (Polycott fabric)

Washing Dyed fabric

Fig: - kuster’s dye pad

The cold pad batch machines are used for applications of only reactive dyes. There

are three cold pad batch machines from benninger known as kusters dye pad.

The colour requirement of a fabric is directly dependent on the following:

The length of the fabric to be dyed

The pick up of the fabric in percent

The GLM of the fabric.(Gram per linear metre)

Dyeing process takes around 16 hrs for dyeing at room

temperature. It can produce a range of light, medium

and dark colours. CPB has a vertical arrangement of

rollers for dipping the fabric in dye solution. The count of

rollers may vary from 1 to 4.

The machine may operate in a range of 50-60 mts/min.

The dye to chemical ratio may vary but standard ratio

used is of 4:1.

The various chemicals used in the dyeing trough are:-

Fixer chemicals - Sodium silicate and Rocoflo - anyone used for fixing.

Reactive dyes .

Soda and caustic

After impregnation of the dyestuff the finishing rollers and squeezing unit squeeze

out the unrequired dye solution. These batches then require fixation/curing dwell

time for which the batches are kept under rotation(to avoid any leaching out of any

dyestuff) in the RFD storage generally for 16 hrs.Each machine has 3 dye and 2

chemical tanks with each having a capacity of 800 lts. Approx production is 20,000-

22,000 mts/shift.

Benefits of Cold pad batch :-

Uniform linear liquor application by two deflection-controlled rolls throughout

the entire batch.

“n” number of reproducibility of all dyestuff and chemical applications.

No side-to-center shading, due to smooth treatment of the selvedge’s


Fig:-single dip single nip

1.5.3 MONFORTS THERMOSOL

The

Monforts thermosol is a continuous dyeing range in which the pre-treated fabric is


Fig: Dye solution

Fig:- Monforts Thermosol

given as input and a completely dyed fabric is received at the output which is then

sent for finishing. This is mainly used for the following types of dyes:

Disperse modified vat dye and reactive

There are 2 monforts thermosol which have similar construction and only differ in the

number of IR dryer Chamber which one machine has a single unit

while the other has two, requirement of dryers depends upon the application

required. The machines have a Thermex hot flue chamber which has 28 rollers in 3

chambers.

The temperature of the chambers are:

Dye Chamber1 Chamber2 Chamber3

Vat 110oc 110 oc 120 oc

Reactive 110 oc 110 oc 120 oc

disperse 180 oc 203 oc 203 oc

The chemicals are put in the wetting chamber along with dyes which includes :

Binders

Softner

Glaubers Salt

Acetic acid


Fig:- IR dryer

Fig:- Monforts Thermosol Dyeing Range

The fabric is fed through the Feeding section which then passes into the section

Wetting unit where it is dipped in the akalis required for dye fixation and dye

solution are present as required. The fabric then passes on to air passage rollers

that assist the penetration of dyes after which fabric pass into the IR dryer units

where through heat of the IR burners partial or pre-drying is performed where up to

40 % of the moisture is removed. Temperature is maintained at 450oC , the fabric

then passes into the Thermex hot-flue where the measuring and control unit

(chamber atmosphere) control the temperature and the Steam injection unit

provides steam for heating the chamber. After the curing process the fabric is

completely dyed and received at the Outlet section. The speed of the machine varies

from 45-50 mts /min and generally runs at 25-30 mts /min at a average.

1.5.4 BENNINGER THERMOSOL

The Benninger thermosol is mainly used for vat , reactive and disperse dyeing

process. The machine is mainly based on the working process principle of pad-dry


Fig:- Beginner thermosol

pad steam method in which the dye impregnation and drying is done on the

themosol while the pad steam/curing is performed on the Benninger pad-steam

machine.The fabric is fed into the machine by various rollers /a scray. The fabric

subsequently enters the dyestuff trough where it comes in contact with the dye

solution, application method used is of single dip single nip. Then it passes through a

intermediate air passage which assists in the dye penetration and then passing into

the IR dryer unit for the purpose of pre drying which composes of 3 units and 3

burners heated at gradually increasing temperatures up to 450oc. the pre drying

process helps in removal of up to 40 % of the moisture. After pre-drying the fabric

enters the therm fix hotflue chamber in which the fabric is passed and dried at high

temperature and high pressure, thus resulting in a completely dried fabric as the

output.

To constantly provide dyestuff solutions there are 5 storage tanks of which 4 are dye

tanks and 1 is of chemical is of 4 with capacities ranging from 500-1500 lts. The

dye: chemical ratio thus is maintained at 4:1 at an average.

1.5.5 BENNINGER PAD STEAM

The pad steam machine lies in line with the thermosol machine for completion of the

PDPS process(Pad dry Pad steam). The Benninger pad stream machine is basically

used for the following purposes:-


Fig:- Benninger pad steam range

Colour development

Reduction clearing in case of blended fabric double bath dyeing.

There are 3 Benninger pad steam machine’ s available for the above said

objectives.Dyes which are processed in the pad steam machine are:-

Reactive dyes

Vat dyes

Chemicals used for reactive pad steam process are:-

Salt

Soda ash

Caustic

Chemical for vat dye pad steam process is: - caustic hydro.

The fabric is fed through feed rollers into the chemical trough where alkali for

fixation /chemicals for reduction clearing are applied on the fabric through single nip

single dip method after which it passes into the booster chamber where the special

squeeze nip of the booster guarantees a uniform pickup, independent from

production speed and fabric weight. The fabric then moves into the recta chamber

with rollers where steam treatment is given to the fabric at high temperature and high

pressure.

After which the fabric passes on to the extracta chambers. There are 9 extracta

chambers that are used for the purpose of soaping, washing, neutralization and

reduction clearing. In first two extracta chambers washing takes place at room

temperature. In the following two chambers H2O2 for oxidation is added at 600C.In the

next 3 chambers soaping and hotwash is done. In the concluding 2 washing


Fig:- Reacta chamber

chambers hot wash with neutralization is at 90-950c degrees. The delivery customer

cylinders nip out any moisture in the fabric with steam heated cylinders and fabric is

received in dried condition as output. The processing speed at an average is 50

mts/min.

1.5.6 BENNINGER WASHER /SOAPER

The Benninger washer or soaper does the basic function of washing after the dyeing

process in order to remove any unfixed dye on the fabric surface. There are two

such machines which have in addition to them an Arioli flash ager which is a

steamer used for two phase printing for a shortening dwelling time for fixation of

dyes in printed fabrics.

Printed fabric washing

Fabrics which are two phase printed using the vat

dyestuff in a oxidized dyestuff without reducing chemicals

and dried are treated with a chemical bath containing the

reduction chemicals and alkali padded with face-side out

using the kiss roll application technique and usually only

the printed face is in contact with the fixation solution,

after which, steaming and washing is done.

Dekol+peroxide +acetic acid mixture is used for the

soaping and washing of printed fabrics.


Fig:- Continuous Pad steam range

Fig:- flash Ager

Recipe used in the flash ager:-

Glaubers salt

Maize starch cooked.

Invitier MR

Soda ash

Borex

Caustic 48TW

Hydro

Dyed fabric washing

The machine has in total 9 chambers in which 2 initial extracta chambers are for

rinsing purposes and I chamber for application of the required chemicals during

processing next 5 chambers are the washing setup which is used for washing after

the dyeing . The soaping is done in two ways:

Cold Pad Batch Wash

Cold Wash

Cold Pad Batch wash –

Dekol fbsn and acetic acid mixture is used for dyed fabrics from cold pad batch the

fabric is first set for relaxation and passed through the heated chambers given as

under

The fabric is treated with water at 30OC ,then treated with water at 40oC,then a soap

solution of DECOL FBSN and acetic acid is applied at 60C,Normal washing with

water at 90C takes place in the next 5 chambers ,Green acid of neutralizes the

fabric at 80oc in the last neutralizing chamber


COLD WASH – Cold wash is given to fabrics coming direct from the continuous

dyeing range. The fabric is passed through the heated chambers given as under:

The fabric is treated with water at 30oC. It is then treated with water at

40OC. A soap solution of Arieanal +acetic acid is applied at 50C.Normal

washing with water at 50C takes place following which green acid of 160 gpl

neutralizes the fabric at 50oc. The maximum speed of the machine goes up

to 40 m/min.

The second washer has drums in its extracta chambers which are also known as

Trikoflex; this makes it preferable for medium weight and light weight fabrics.

2. KNITS DYEING

2.1 INTRODUCTION

Once the Marketing Department informs the PPC about the order given by the buyer,

the PPC plans the amount of fabric to be made in the Silvassa’s Knitting unit before

being sent to Vapi for processing.Buyers’ Specifications include the amount of

the fabric, the GSM etc. A specified percentage weight of fabric is

processed in extra to meet consumption of fabric during the series of

processes involved.

2.2 PROCESS FLOW FOR KNIT DYEING


FABRIC KNITTING

GREIGE DEPT

2.3 GREIGE DEPARTMENT

There are 4 griege opening machine of

Hsing cheng of which there are two

machines each for open width and double

folding . Double folding machines change the

open width to tubular form for better dye pick

up. Opened fabric are then received in

plated form in a trolley.

The mechanism involving tubular conversion

is a folding device for joining the two ends

along the length of the fabric and the stitch

the ends together with the help of a Kansai Sewing Machine. The machine is

equipped with sensors to open the curved edges. The production capacities of these


DYEING

FINISHING

INSPECTION

PACKAGING

Fig:- Hsing cheng open width fabric opener

machines are 1500 kg/day whereas of open width grey opening machines it is 2500

kg/day. After the grey opening, the fabric is sent to the dyeing department in trolleys.

2.4 DYEING OF KNITS

Dyeing of knits is a delicate process for which rope dyeing in soft flow machines is

preferred to avoid any unnecessary stretch that may occur during dyeing process.

The dyeing is mainly of reactive and disperse type. There are 20 Sclavos Athena soft

flow machines with capacities varying from 500-1500 kg the plant has a capacity of

850 tonnes per month.

2.4.1 DYEING PROCESS FLOW

IF LYCRA NO STRECH FIBER


Fig:- Hsing cheng Double folding machine

GREY OPENING

FINISHING

HEAT SET PRETREATMENT + DYEING

2.4.2 DYEING PROCESS

Fabrics blended with stretchable fibres are heat set

immediately after the opening of the fabrics rolls to set the

yarns in the fabric and avoid any unnecessary stretch.

Knit dyeing is basically carried out in batches. The dyeing in the soft flow machines

begins with the RFD batch dozing into the machine through machine windows in

rope form with one end tied along with a magnetic type piece so as to receive the

tied knot after dyeing at the window after which water through the circulation pies is

pumped and a hot wash at 80oC is given followed by a cold wash. The pre

treatment chemicals such as :- Wetting agent, NaOH provides assisting in impurity

removal, H2O2- Hydrogen peroxide used as a bleaching agent are dozed from the

addition tanks provided besides the machine with the ph maintained at 6.During all

the dozing processes the fabric rope rotates on the tied reel in clockwise direction .

After pre treatment the dyeing chemical dozing is done after chemicals from the

storage tanks are mixed in the addition tanks at 60oC for 15 mins, following colour,

salt and soda dozing. After the required dwelling time an acid dozing is done


Fig :- Sclavos Athena

http://www.sclavos.gr/portal/images/stories/fabric_dyeing_machines/athena2/athena2.jpg%00%E5%A1%B9%EF%92%81%E1%B4%BB%E4%A1%BF%E2%B2%AF%E5%B6%82%E8%97%84%E6%8C%A7%00%00%EA%AE%A5

following which soaping and rinsing along with a hot wash and cold wash. Softeners

are also used during the soaping for finishing purpose if required.

Temperature suitable for dyeing some fibres are as follows:-

Cotton :- 80oC – 850C

Polyester: - 130 oC -135 oC.

Dwell time required for various shades

application: - Light :- 6-6.5 hrs, Medium –

7.0-7.5 hrs, Dark- 7.5-8.5 hrs, Extra dark:-

more than 8.5 hrs.

3. YARN DYEING

Yarn dyeing is a process of imparting color to a greige yarn. Thet yarn packages of

greige yarn comes to Yarn Dyeing Department from the Spinning unit (Silvassa).

These come in cheese forms having cardboard package material at the core.the

range of yarns available range from 4s to 2/100s.

There are two types of dyes used in the department.

(a) Vat Dye

(b) Reactive Dye

3.1 PROCESS FLOW FOR YARN DYEING


Winding

Dyeing

Pre-treatment

Fig:- SOFT FLOW MACHINES

3.2 WINDING

The first process in yarn dyeing is winding. Winding is required to transfer greige

yarn from standard cardboard packages to soft packages. These soft packages are

perforated in nature and are necessarily required for penetration of dye liquor into

the package during the dyeing process.As the greige yarn cone package has non-

uniform density thus to make the package of uniform density it is necessary to wind

it.

There are 5 SSM winding machines of which 3 of model TW 1-W with 50* 2 spindles

and 3 of model PSW6 with 96 * 2 spindle. The diameter of the soft tube used is

74mm. The soft cones can be either be of plastic or of spring shaped steel tubes. A

high speed winding is done from the greige packages to soft packages with Weight

of the soft packaged yarn being constant at 1.15kgs.the finished width of the yarn

packages range from 165mm-175mm.

The dye package has the following requirements according to the different

influences on the dyeing process:

Density:


finishing

Drying

Rewinding

The regularity of the density within a package and from package to package has to

be in a range of +/- 2.5 with regard to the capacity of the dyeing equipment the

density should be as high as possible. This parameter is auto controlled on the

machine.

Shape:

Cylindrical packages are the preferrable for dyeing as cylindrical packages help

optimum packing of the dyed vessel. Additionally the cylindrical packages have an

even flow resistant which makes it much easier to achieve an even distributing of the

dye stuff. Straight sides ensure an optimum sealing between the packages to avoid

by-passing of the dyestuff.

3.4 LOADING


Fig :- Requirements For soft cone winding

Fig:- Rockwell Double girder crane

After winding of soft packages, these are stacked/loaded on the package carriers

which vary in capacity as per the machine in which they are used. These have

perforated rods for circulating dyestuff and chemicals. The package carriers are then

carried by a crane to its respective machine for dyeing purpose.

3.5 PRE-TREATMENT

Yarn dyeing is done in batches. After placing the yarn carriers in the dyeing

machines of suitable capacity the pre-treatment ,dyeing and finishing of the

yarns is performed together. In pre-treatment, scouring is done as the first step.

Thereafter, yarn is put through a caustic soda bath followed by hydrogen

peroxide and acetic acid treatment along with other chemicals. This process is

carried out at 100°C.

Machine capacity Number of machine

25kgs 3

50kgs 2

54kgs 3

553kg 2


Fig:- Fong’s yarn dyeing m/c

750kg 3

1070kg 3

(sample dyeing)

6kg 3

3kg 3

1kg 3

3.6 DYEING PROCESS:

After the completion of the pre-treatment processes the chemicals are flushed out of

the chamber and the packages are rinsed with water pumped in from the addition

tank, simultaneously the chemicals and dyes required are prepared in the storage

tank for dozing after rinsing. Then as per required sequence dozing of chemical and

dyes are done with required dwell time. The dyeing can be of isothermal or migration

type. Depending upon the intensity of the shade various temperatures and dwell time

are as follows:-.

Light shades - 60°C - 70°C for 40 - 60 mins.

Medium shades - 80°C - 90°C for 60 – 80 mins.

Dark shades like black - 80°C - 110°C for 80 – 90 mins.

Chemicals used in dyeing are Glucose, Caustic soda, Sodium Hydrosulphite and

Glauber’s salt.

After the dyeing is finished then neutralization is done with an organic acid followed

by soaping, hot wash and a cold wash.

3.6 FINISHING

Post dyeing the yarns are given finishing by the following chemicals :- Hydrogen

peroxide, Pervalin RS, Acetic acid and Perfil 210.This process is carried out at

95°C.After finishing the packages are removed from the machines and dried in the

hydro extractor and electro-magnetic dryers and then rewinded on cardboard


packages from soft cone by SSM rewinding machines, after which the packages are

ready for packaging dispatch. The total time taken for the whole process i.e. pre-

treatment, dyeing and finishing is 6 – 8 hrs, depending upon the intensity of the

shades.

4hrs - white shades,

6 hrs - light shades

6 – 8 hrs for dark shades.

4. DYEING OF TOWELS.

.

4.1 INTRODUCTION

Dyeing of terry towels which has 100% cotton content reactive dyes are used

because they are good colour fastness, eco-friendly, and also cheap.Rope

dyeing is preferred mode of dyeing for towels as padding towels would tend to

destroy their terry (pile).

4.2 PRE- TREATMENT

Pretretment of towels is done in Benninger PTR range similar to that which was

used for woven pre-treatment. The towel PTR range differs in only an additional

reacta chamber meant for enzymatic desizing purpose. The following chemicals are

used for pre-treatment purpose:-

Desizing agent

Wetting agent

Lubricating agent- reduce surface tension

Sequestering agent-reduce water hardness

H202


4.3 DYEING

Dyeing of towels is preferably done in a soft flow

machine so as to avoid any destruction of

piles/loops on the surface of the fabric. The rope

dyeing technique is similar to that of knits. In

rope dyeing the towel rope is run in

predetermined number of cycles with a pre

determined cycle time with max speeds upto 250

rpm. There are 7 theis soft flow dyeing machines

with capacities ranging from 350 kg-1400 kg.The

pre treated towels are dosed and then a rinsing

is done after which dosing of dyeing chemicals is

done. Liquor ratio(M:L) used IS 6:1 lt/kg. The

various Chemicals used for dyeing purpose are:-

Dyes:- Reactive dyes

Lubricants

Sequestrant

Levelling agent-

Salt

Soda ash-to maintain alkaline medium

Acetic acid

After the dyeing process soaping with dekol fbsn is done followed by neutralization

by green acid and to give a soft feel softners of caustic and silicon base may be

optionally added.


The dwell time required for various colour shades are:

Light :-

4 hrs

Mediu

m :- 5

hrs

Dark:-

6hrs

Extra dark:- 8 hrs.


Machine capacity(kgs) Number of machines

1400 1

1050 1

700 1

350 2

90 2

5. Colour Kitchen

Colour kitchen is an area where dye solution is prepared for bulk dyeing as per the

recipe given from the laboratory. They have particular codes of various colour

recipes. The proportion of chemical and dyes required for a particular is already fed

into the computer. Whenever a batch card with the particular colour code comes to

the colour kitchen that particular code number is fed into the computer and the

respective proportions of dyes and chemicals is automatically taken. After this the

prepared solution is passed to various tanks stationed beside the dyeing machines

by means of pipes.

There are different colour kitchens for the following departments:

Woven processing

Knits and yarn processing

Printing

Towel dyeing


PART IV.....

PRINTING


PRINTING OF WOVEN AND KNITS FABRIC

Printing is the textile processing technique for localized application of dye/pigment is

a desired pattern /design. The styles of printing are carried out are

reactive,discharge(white and colour),pigment. The printing section has its own

design studio and colour kitchen for screen,dye/pigment solution development .

1.1 DESIGN STUDIO

The studio is responsible for the designing of the designs for screens which are

required to be developed in accordance to the design specification provided by the

buyer. There are 5 workstations which are equipped with Ramsete III version 8.33

for design development. Screen preparation department is the provided by the ready

designs and its specification for the preparation of screen.


Printing Department

Design Studio Colour Kitchen Printing

ENGRAVING:

After receiving the design developed for screen, work in the screen preperation

starts with the engraving. Nickel made Fine mesh ready screen of varying

circumferences of 640mm,819mm and 914 mm

are available .CST Inkjet printing unit is used for the purpose of engraving.Coating of

the screens is done with the combination of three constituents namely, Photo

emulsion (readymade liquor), Dichromate and Distilled water which is done as per

the design The design development is done through the ink when the screen is

exposed to uv-light ,coating hardens to retain itself and then washing in reggiani

screen washing machine to wash off the undried ink, thus the inked part becomes

the area of penetration for the colour

pigment in the rotary screen.

Thereafter the coating on the screen is

cured in the embee curing machine

for 2 hrs at 100°C f. After which the

screens are finally dried in the

femate Climatizer


Fig:- ENGRAVED NICKEL SCREE

DIGITAL PRINTING:

The screen preparation department also

houses Mimaki Textile Inkjet is the machine

used for digital printing. Digital printing is

done at a very small scale for only special

purposes. Any type of fabric can be printed

upon using this machine

Appoximately 60 million colors can be printed using this machine. Ripmaster is the

CAM used for controlling these machines operations.

1.2 AUTO KITCHEN

Auto color kitchen is responsible for making the paste for printing by using various

chemicals & dyes and regularly suppy the machines as required.

The kitchen has 5 silo storages for urea(hygroscopic agent),sodium bicarbonate,

Potassium carbonate used for reactive printing paste, Resist salt(oxidizing

agent),soda ash. These silos supply to the automatic prepeartion unit(1000 lts) for

paste preparation.


Fig:- CST SCREEN ENGRAVING MACHINE

Fig:- Mimaki Textile Inkjet printer

Key Ingredients for printing paste are :-

Binder: - 18% binder is used for dark shade.

6% binder is used for lighter shade.

Luprimol (STG) - It act as softner which reduces hardness of the water and paste

soft.

Lutexgel(HIT) - It act as thickner to make viscous paste of the dye.

Fixing agent(LF) -It act as fixer & rubbing fastness will increase.

Rongolite (ST) -It act as reducing agent for white and color discharges.

For 100 % cotton fabric sodium sulphoxylate is used , for blended fabrics Zinc

Sulphoxylate is used.

There is a roto mix machine for the colour preparation which is dosed by chemical

by various dosing systems which prepare the colour paste in large open tubs which

are transported to the machine for dosing the paste to the screens.

1.3 PRINTING:

The Textile printing practised at Alok is the rotary screen methods for which there

are 3 Reggiani rotary printing machines, 1 Lakshmi rotary printing machine and a

sample printing machine from Reggiani. In addition to this there are Two Aroli Loop

Agers that are used for the purpose of curing.


1.3.1 PROCESS FLOW FOR PRINTING

REACTIVE PRINTING

DISCHARGE PRINTING

PIGMENT PRINTING

1.3.2 PREPARATION OF CLOTH FOR PRINTING

The wet preparatory processes are all carried out on the Benninger PTR where as

for knits its done in the Sclavos soft flow machines. Apart from wet preparations the

cloth is brushed & sheared on lafer shearing machine by being passed over

rapidly revolving knives arranged spirally round an axle, which rapidly and effectually

cuts off all filaments and knots, leaving the cloth perfectly smooth and clean and in a


PRINTING PRINTING DRYING

DRYING SOAPER

SOAPER STEAMING

STEAMING

FINISHING

FINISHING

PRINTING PRINTING DRYING

DRYING CURING

CURING STEAMING

STEAMING SOAPER

SOAPER

FINISHINGFINISHING

SOAPER

condition fit to receive impressions of the most delicate engraving. Some figured

fabrics, especially those woven in checks, stripes and crossovers, require very

careful stretching and straightening on a stenter frame, before they can be printed

with certain formal styles of pattern which are intended in one way or another to

correspond with the cloth pattern. Finally, the cloth is wound around a hollow

wooden or iron centers into rolls of convenient size for mounting on the printing

machines.

PRINTING MACHINERY

A rotary printing machine prints designs with enraved designs on a curved cylinder..

Substrate here is a continuous fabric roll which is to be printed and further modified

if required (e.g. die cut, overprint varnished, embossed).

The initial development of the samples is done using CAD in the studio using which

the screens are developed after which the Reggiani sample printing machine is used

for preparation of samples . The normal width of this machine is 70”. It can be

extended up to 120’’

1.3.3.1 LAKSHMI ROTARY PRINTING MACHINE

For printing, rotary printing machines are

used which is of an Indian brand –

Lakshmi. Up to 12 colors design can be

printed in this machine. The screens are

mounted on the screen stations

provided ,for each color in the design a

screen is used with the color paste being

provided into the screen through a pipe

and a squeeze arrangement within the

screens apply pressure to enable printing

paste penetration.


The fabric is fed through rollers to the printing table and is stabalized in width by a

guiding system .As the fabric passes under the screen rollers the colors are applied

as per design. The capacity of this machine is 20 to 100 meters/seconds depending

upon factors like design and the number of colors in that design and the types of the

fabric (coarser takes less time as compared to finer fabric).The machine is pre-

equipped with the under-bed washing and drying unit which cleans and dry up the

belt after each cycle . After printing rollers, the drying unit dries printed fabric in a 5

chamber arrangement dedicated for drying. After drying, the fabric is sent to the

polymerizer for fixation, i.e. the fixing of dyes /pigments.

1.3.3.2 REGGIANI MACHINE


Fig:- Reggiani screen printing range

Fig:- Lakshmi screen printing range

There are 3 Reggiani rotary printing machines out of which 2 machines can print up

to 12 colors and the third machine can print upto 14 colors. The Reggiani screen

printing range is has similar operation run as that of the Lakshmi rotary printing

machine. The only difference in both the machines is the application of glue in the

Reggiani machine by a glue roller that ensures that the fabric sticks to the running

conveyor belt as it passes under the various screen rollers for coloration.

After printing it enters the heating chamber where there are 5 chambers that dry the

printed fabric with high temperature and pressure. Two machines out of three have

the dryer in on-line position where as the third machine has an dryer in over head

position. The dried fabric received is then received in a batch form or plaited

(preferable) and then sent for curing.

Technical details of Reggiani Rotary printing machine

Number of colours 12 & 14(max 24 colors)

Printing speed 30 to 45 m/min max(90 m/min)

Printing width 72” to 80”

Multi repeat printing heads (screen

size)

640 to 1200 mm

Squeegee system UNIFLUX continuous magnetic

field


Fig:- Reggiani Screen printing machine

Process control for Reggiani dryer

Reactive printing

I Chamber 1500c +/- 15

II Chamber 1500c +/- 15

Speed 30 +/- 15 mts /min

Pigment printing



Speed 40 +/- 15 mts /min

Discharge printing



Speed 20 +/- 10 mts/min


1.4 ARIOLI LOOP AGER

After the printing process is completed the fabrics have to

undergo a curing process for the polymerization of the

dye applied in printing.

To perform the required curing process and polymerization of pigments with

standard long loop treatment there are two Arioli Loop Agers available which fix the

dyes through high temperature treating with a suitable dwelling time. This machine is

suitable for both woven and knits .The fabric is then fed into the loop ager chamber

where short loops are formed which allows increasing the dwelling time. With such a

system, the most delicate discharge prints and colouring overlapping may be safely

treated without risking rubbing or marking. Pigment prints polymerizing in hot air is

done at temperatures up to 160°C. If reactive dyes are used, the temperature of the

dye is kept 102°C


Fig: Arioli loop ager machine

Fig: Arioli loop ager curing range

Process control of loop ager printing machine

Pigment printing

Chamber 1 160oc

Chamber2 160oC

Speed 39 mts/min

Reactive printing

Chamber 1 107oc

Chamber2 102oC

Speed 24 mts/min

Discharge printing

Chamber 1 107OC

Chamber2 102oC

Speed 33 mts/min

Technical details of loop ager

Fabric capacity 87 yds/80 mts

Roller widths 87’’

Working speed 22 yds/min

Dwell time 4-40 secs


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