performance evaluation & textile material ll
TRANSCRIPT
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