TO OUR PRESENTATION

Pilling

• Pilling is a fabric surface fault in which “pills”

of entangled fibres cling to the cloth surface,

giving a bad appearance to the garment.

• The pills are formed during wear and

washing by the entanglement of loose fibres

that protrude from the fabric surface.

• Under the influence of rubbing action, these

loose fibres develop into agglomerations

anchored to the fabric by a few unbroken

fibres.

Factors Affecting Pill Formation

Pilling, dynamic process

Pilling rate > pill break-off rate = pill buildup

Pills build up is affected by

Number of protruding fibre ends

Fibre linear density

Fibre length

Fibre cross sectional shape

Fibre strength modulus and friction

Yarn twist levels

Fabric construction

Dyeing

Finishing

Mechanism of pilling

Pilling is generally considered to

be a self limiting process

occurring in four main stages

fuzz formation

fuzz entanglement

pill growth

pill wear-off

Test result showing maximum pilling of various

fabrics

Pills

(mg/cm2)

Number of Revolutions

1. Nitrile Acetate

2. Polyester

3. Polyamide

4. Acrylic

Fibre length 90mm, Count 3.3 dtex

Pilling of Various Fabrics

1. Acetate

2. Wool

3. Acrylic

4. Fibranne

5. Polyamid

e

6. Polyester

Nu

mb

er o

f P

ills

/in

ch2

Test Time Hours

Mechanism of pilling (cont..)

Figure 1 and 2 show test results of maximum

pilling of various fabrics. The curve number 2 in

Fig 1 is the most typical pill curve with a distinct

maximum pills followed by a progressive

reduction in pills as pill wear-off exceeds pill

formation. If the fabric is madeup of strong fibres

the third step i.e. pill wear-off delayed and the

pill density remains close to the maximum

number 6.

Typical curves for fuzz formation

FU

ZZ

WT

, M

GS

Time of Brusning, (min)

Pill curves for several modified polyester fibres

Mechanism of pilling (cont..)

Fig 3 & 4 and Table 1 show relationship

between fibre properties and stages of pilling

Stage Fibre Property

Fuzz Formation

Friction

Stiffness

Breaking Strength

Abrasion-resistance

Entanglement

Shape

Linear Density

Stiffness

Recovery

Friction

Elongation

Pill Wear OffBreaking Strength

Flex Life

Fibre properties affecting the stages of pilling

Fibre Parameters

1. Stages in life span of pills

2. Fiber type

3. Fibre length

4. Fibre friction and cross section

5. Fibre tenacity and bending resistance

6. Inter fibre friction

7. Fibre crimp

FibresFlex life

Cycles

Tenacity Modulus Friction

(mg)Fuzz (mg)

gf/den gf/tex gf/den gf/tex

Nylon 26,000 4.5 0.50 6 0.67 0.29 6.0

Viscose 70 2.6 0.29 69 7.66 0.22 4.4

Dacron 13,000 3.9 0.43 29 3.22 0.35 3.1

Orlon 1,870 2.2 0.24 52 5.77 0.35 3.1

Wool 3,620 1.4 0.16 24 2.66 0.15 0.4

Acetate 20 1.4 0.16 13 1.44 0.30 0.4

Fuzz Tendency of Various Textile Fibres

Yarn Parameters

1. Yarn type

2. Yarn Count

3. Twist

4. Blend

5. Yarn hairiness

6. Yarn Doubling

Effect of Polyester-fibre Type and Spinning System on

the Pilling of Sweatshirts

Polyester Fibre

TypeS

pin

nin

g S

yst

emRTPT

Ratings

(min)

5 Wearings/Washings 5 Wearings/Washings

Wear Test RatingsNo. of

Pills

per

10.5cm2

Wear Test Ratings

No. of

Pills per

10.5cm230 60 120 Front Back Sleeve Front Back Sleeve

Very pill-

resistant Rotor 3.8 3.0 2.5 3.3 3.3 3.2 24 2.9 3.5 2.8 42

Pill-resistant Rotor 3.0 2.0 1.5 2.6 3.0 2.2 59 2.0 2.5 2.1 86

Non-pill-

resistantRotor 2.2 1.5 1.0 2.2 3.0 2.0 96 1.5 2.3 1.8 >100

Very pill-

resistant Air-jet 4.0 3.5 3.2 4.2 4.5 4.2 3 -not determined-

Pill resistant Air-jet 4.3 3.7 3.0 4.5 4.8 4.4 3 4.0 4.3 3.9 6

Non-pill-

resistantAir-jet 4.0 4.0 3.5 4.1 4.3 3.8 4 3.7 3.9 3.7 5

Cotton VarietyFibre Length

(mm)

2.5% span length

Mean number of pills/Unit Area

Varalakshmi 37.3 5

Sankar – 4 31.6 15

Effect of length on hairiness of blends

1. Fabric type

2. Fabric cover factor

3. Fabric structure

4. Fabric weight

Fabric Parameters

– Singeing reduces pilling

– Shearing and cropping reduces pilling in polyester/wool fabrics.

– Heat-setting at higher temperature for suitable duration reduces

pilling.

– The cellulosic materials in super steam for heat setting should be

preferred for reduction in pilling.

– Low heat setting temperature for longer duration in

polyester/cotton fabric reduces pilling

– Effect of heat setting of a polyester fabric under tnesion at

different temperature is given in table 5

Dyeing and Finishing Parameters

Heat Setting

Temperature

(oC)

Pill/Unit Area

Heat-set only Boiled-off and Heat-set

Control 6.5 10.2

120 - 9.9

140 11.9 8.6

160 11.6 7.8

180 7.8 7.1

200 8.5 5.2

220 5.0 6.4

Fuzz tendency of heat-set fabrics

SEM micrographs of ...

(a) Untreated cotton fabrics,

(b) 130 W 60 sec. air plasma treated cotton

fabric,

(c) 130W 60 sec. argon plasma treated

cotton fabrics.

Measurement of Pills

1. ISO 12945-1

(Part-I Pilling Box Method)

Determination of fabric propensity to

surface fuzzing and to pilling

2. ISO 12945-2

(Modified Martindale Method)

Determination of fabric propensity to

surface fuzzing and to pilling

3. ISO 12945-3

(Random Tumble Method)

Determination of fabric propensity to

surface fuzzing and to pilling

4. ASTM D 3512-07 Standard test method for pilling resistance

and other related surface changes of textile

fabrics: Random Tumble Pilling Tester.

5. ASTM D 4970-07 Standard test method for pilling resistance

and other related surface changes of textile

fabrics: Martindale Tester

Random Tumble Pilling Tester

Random Tumble Pilling Tester (cont..)

• Determines resistance to

pilling and related surface

changes

• Applicable to knitted and

woven fabrics

• Clear, lighted viewing

chambers

Random Tumble Pilling Tester (cont..)

• Pills result from random

tumble action against a

mild abrasive

• Cotton fiber added to

initiate pill formation

• Air injection system

• Good correlation to end-

use performance

ICI Pilling Box Tester

ICI Pilling Box Tester (cont..)

– During testing, apiece of

fabric is sewn in place

firmly round a rubber tube.

It is rotated in the pilling

box at 60r/min for 5 hours.

– After tumbling, the extent of

pilling is assessed visually

by comparison with

arbitrary standard.

Photos of fabrics after pilling tests

untreated fabric (arrows indicate pills)

fabric coated with SiO2/Al2O3 sol.

Photos of fabrics after pilling tests

(cont..)

Using the viewing apparatus and comparing with photographic

standards samples are rated on the following scales:

Measurement of Pills

5 No Pilling

4 Slight Pilling

3 Moderate Pilling

2 Severe Pilling

1 Very Severe Pilling

The effect of humidity, compressed air injection and time interval on

pilling are shown in Fig 5, 6 and 7

Time Curves for samples equilibrated at different relative humidities,

the sample had a machine tightness factor of 14 tex 1/2cm-1

Effect of Compressed-air Injection on the RTPT Pilling

–Time curve

Pilling-time curves measured by using RTPT and

compressed-air injection

Pilling resistance of jersey fabric with standard yarn

twist

Pilling resistance of jersey fabric with high yarn twist

Pilling resistance of interlock fabric

– Selecting the correct raw materials (fibre).

– Manufacturing yarn through proper pill resistant steps

– Constructing fabrics with suitable parameters

– Using finishing and dyeing techniques for reducing pilling

– .

Control of Pilling

Control of Pilling (cont..)

– Pilling on finished fabric is on the average 85% less than in grey state.

– In polyester/ cotton fabric singeing, shearing and cropping and heat

setting reduces pilling tendency.

– Enzyme treatment given low pilling i.e. Bio-polishing

– Fabric pilling can be overcome by the joint efforts of fibre manuf

actrures, yarn producers, fabric designers and finishers.

– Any anti pilling treatment must not affect the desirable aesthetic, comfort

and performance properties of fabric.

Conclusion