Standard Development and Parameter ofFinishing process in Knit Dyeing

Introduction Finishing is a general term which usually refers to

treatment on textile fabrics after dyeing or printing. It increase life and durability of the fabric. By finishing we can maintain fabric shape and size. Finishing accentuate or inhibiti some characteristic of

fabric. Impart new characteristic or properties. Finishes may be done by chemically or mechanically. To get good finished quality we should maintain

machine parameter or proper chemical recipe. We can improve finished product quality by developing

machine parameter or create new and appropriate chemical recipe.

Objectives

• To improve the appearance of the fabric.• To improve the feel of the fabric by

softening, stiffening, etc.• To cover faults in the original fabric.• To increase weight of the cloth.• Special properties required for particular

uses .

Types of finishingThe most common classifications:Aesthetic finishesFunctional finishes• Finishes also classifies:

finishing

Physical finishing

Temporary

Calendering

permanent

raising

Chemical finishing

Temporary

Starching

permanent

Resin finish,

Mercerization,

Softening, etc

Finishes practiced in Industry

Process Flow Chart of Finishing Section:

Finishing

Tube Form Fabric

De-watering

Drying

Tube Compacting

Open Form Fabric

De-watering

Slitting

Drying

Stentering

Brushing

Open Compacting

dewatering / squeezerAfter dyeing process from the dyeing machine then the fabrics are

ready for de-watering. This is the process to remove the water from the fabrics partially by squeezing.

Process flow chart:

Fig: Crossectional view of Bianco Tube Squeezer.

Basic function of the squeezing m/c:

To remove the water from the fabric. To control the width of the fabric. To control the length of the fabric. To control the spirality of the fabric. To control the over feeding system. To increase the softness of the fabric. To remove the crease mark of the fabric.

Dewatering Machine• Parameter:• Padder (1): 4-5 bar ; Padder (2): 3.5- 4 bar

Fabric type Fabric speed (m/min) Over feed %

Single jersey (Viscose) 50-70 30

Single jersey(Cotton/Lycra) 60-80 22

Single jersey(Cotton) 60-80 10-11

1x1 Rib 20-30 11

Interlock 20-30 14-15

terry 40-50 5-9

Single jersey- 180GSM (exp.) 70 25%

Checking point:Diameter; Fabric speed; Overfeeds; Padder pressure

Development:Wet Squeezer MarksSoftener Mark

Slitting machine:• The slitting machine is used in processing fabrics in the open line in the

finishing section.

Main Parts:• Turn table; • Beater;; • De- twister; • Centering unit;• Slitting unit• Pulley drive• Squeezing

Figure: Passage Diagram of Slitting Machine of Brueckner

Machine Functions:

• To slit the tube fabric by the knife for opening of the fabric and ready for stentering.

• Delivered fabric is crease free state.• Before squeezing balloon is formed with the help

of compressed air passing by a nozzle or air sprayer.

• It can control the diameter of fabric and GSM and shrinkage by over feeding mechanism.

• Soften the fabric by applying the softeners.

Slitting MachineParameter:

Fabric type Speed

m/min

Over feed

%

Padder

Pressure 1

Padder pressure2

Single jersey 60-80 2.5-3 1.5 bar (chemical)- 2bar

(normal)

3 bar (chemical)- 4bar

(normal)

1×1 rib 30-40 2.5-3 1.25 bar (chemical) -3bar

(normal)

2.5 bar (chemical)-

3 bar (normal)

2×2 rib 20-30 2.5-3 1.25 bar (chemical) -3bar

(normal)

2.5bar (chemical)-

3 bar (normal)

Loop back 20-30 2.5-3 1.5 bar (chemical)- 2bar

(normal)

3 bar (chemical)- 4bar

(normal)

Single jersey

(160GSM) EXP

75 2.8 1.5 bar 3 bar

Checking point:Needle line; machine speed.

Development:

Softener spot Improper slitting

Dryer:• The machine is used for removing the residual water contained in the

fabric after squeezing by applying heat on the fabric in the machine.• the fabric is feed on the drying net at low over feed speed and the

humidity is continuously measured.• Drying is done by applying heat through burner nozzles.

Main parts:• Heating chamber• Blower• Synthetic blanket as a conveyor• Folder• Exhaust fan• Steam valve• Conveyer roller• Tension roller

Machine Functions:

• To dry the fabric with help of steam• To control the shrinkage• To prepare for next subsequent process• To dry tubular and open width fabric

without tension.• To remove residual water containing in the

fabric.

Dryer Fabric

type

Color Speed Over feed Temperature

(°C)

Stretch

(%)

s/j White 10 15-20 120 35

Dyed 8-10 15-20 120-130 35

PK White 12-15 30 120 50

Dyed 15 30 120-140 50

1×1 rib White 7-8 10 120-140 20

Dyed 7-8 10 130-140 20

2×2 rib White 7-8 20 120 25

Dyed 7-8 20 120-130 25

s/j (160 GSM) EXP. White 10 20 130 35

Parameter:

Checking point:Speed; Temperature.

Development:Overheating and Shade Variation.

Stenter Machine:

• Stenter is used for open form fabric. It is the heart of open knit finishing sector.

Main Parts & Zones:Back Zone: • Guider • Two Baths & Padder or Squeezer• Auto centering Middle Zone: • Over feed regions• Blanco or Mahlo arrangement• Chain & clip system; • Chambers (Contains blower, heater, recovery) Front Zone: • Over feed zone • Plaiting; • Static electricity remover

Figure : Passage Diagram of Stenter

Machine Functions:

• To control the shrinkage• To control the required GSM by overfeed• To control the required dia.• Heat setting• For straighten the fabric• To control bowing & bias (spirality)• For uniform moisture content• Finishing chemical application

Stenter MachineParameter:

Fabric

Parameter

Single jersey l-Rib PK Fleece/ terry Single jersey

EXP.

Required Dia (cm) 88 80 54 80 190

Actual Dia (cm) 90.5 88 67 84 208

Required GSM 160 240 210 240 260

Actual GSM 148 218 185 232 240

Temperature (°C) 170 170 170 170 160

Overfeed 60 45 60 40 40

Machine Speed 20 18 18 16 20

Controlling point:Temperature ; Width setting; Overfeed; Speed.

Development:Spirality problemGSM variation & width variation for lycra fabric.Wrong and narrow widthStartch stains and white lines on finished cloth

TUBE COMPACTOR:• The treatment of knit fabrics in tubular form on the

TUBULAR COMPACTOR meets the exacting standards set by customers

Main Machine Parts:• Feed section: Tension control & Metal detector. • Shape: Set according to the dia. of fabric • Steam zone• Take out & Plaiter zone • Compacting Zone:

Fig: Cross sectional View of Tube Compactor Machine

Basic functions of the machine: • To control the GSM. (Increase & decrease). • To control the dia. • To control the shrinkage. (Increase & decrease).• Width control through a steeples adjustable

special tubular fabric spreader driven by variable speed motor for distortion-free fabric guidance.

• Steaming with a condensate-free steam box which is easily operated and completely made from stainless steel.

• Compacting through two Nomex felt belts.• Calendaring while passing between the felt belt

and the heated shrinking rollers.

Open Compactor:• Open Width Compactor is suitable for open width knit fabrics to achieve

exact dimensional stability and a soft feel.

Main Parts of the Machine:• Heating chamber • Blower (2, one at the entry chain zone for uncurling and another at the

entry of compacting zone) • synthetic blanket as a conveyor, • Folder • Exhaust fan • Unpinning cylinder (-40% (+-)40%) • Belt cylinder (-40% ( +-)40%) • Uncurling device at entry of compacting zone. • Sensor • Brush roller

Figure: Passage diagram of Corino Open Compactor

Machine Function:

• To compact the fabric• To control the shrinkage• To maintain proper width and G.S.M• To make the fabric surface smooth

Open Compacting MachineParameter:

Over-feed ratio: Edge drive zone – 1.0-1.5 Retard roller – 0.80-0.85 Take-out zone – 0.85-0.90 Conveyor belt – 1.0-1.05 Plaiter – 0.80-0.85

Shoe pressure: S/J – large dia. – avg. 30 psi S/J – smaller dia. – 10-15 psi Rib – 10-20 psi Lycra - <10 psi

Types of fabric

Buyer Color Over feed

Reqd. GSM

FinishedGSM

M/C dia. (cm)

Reqd. Dia.

Finished dia.

Temp 0C

RPM

Single jersey Name IT Black 60% 180 178 115 100 98 1100C 15

J &J Navy 60% 190 207 195 64 71 1100C 1811 Rib Pimkie 0350 60% 210 205 210 74 75 1000C 1822 Rib (lycra)

Russel Black 60% 180 180 180 64 68 1100C 18

Interlock Kappa Khaki 60% 260 300 200 75 72 1100C 18

Polyester fabric

Rex & Holm

Khaki 60% 190 185 190 64 67 1100C 20

Fleece Kappa Blue 60% 260 228 210 74 77.5 1100C 18Interlock EXP. Blue 60% 330 288 224 222 1150C 20

Development: Folding Marks GSM Variation

Raising:• During raising, the fabric surface is treated with sharp teeth to lift the surface

fibres, thereby imparting hairiness, softness and warmth, as in flannelette.

Main parts:• Return drag roller• Pile• Counter pile• Front drag roller• Suction pump• Drum• Plaiter roller

FeedDelivery

PileCounter

pile

Front drag

Roller

Rear drag

Roller

Return drag roller

Plaiter roller

Figure : Cross-sectional view of Raising Brush machine

Machine Functions:• To obtain a lofty handle effect on fabric.• To obtain fleece appearance.• To create pile on fabric surface.• To produce a heavier surface made of

fibers.

Some Chemical Finishes

Softeners• Softening treatment is one of the most important chemical after treatments in the

textile industry.• By softening treatment textile can achieve not only soft handle but also:

Some smoothness. More flexibility. Drape and Pliability. Antistatic properties. Luster. Soft handle.

Types of softeners:

Nonionic Softeners:

Anionic Softeners:

Silicon based Softeners

.

Softeners

RESINS

Advantages:• Resins have a profound effect on and cause changes in the

hand (feel), drapability and physical characteristics of textiles.

• They add stiffness to fabrics and are thus used as stiffening agents or to create a firm hand.

• Yarns in fabric will be stabilized and will resist shrinkage in laundering.