Transcript Pilling

Pilling
Dr. Jimmy Lam
Institute of Textiles & Clothing
Agenda
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What is pilling?
Definition
Measurement of Pills (Testing)
Factors affecting pill formation
Yarn (Open-end; Ring spun yarn and
air-jet)
• Fabric (Woven and Knitted fabric)
Pilling
• 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.
Definition
• 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 entanglements of loose fibres
that appear on the fabric surface are called
“pills”.
• The International Fabricare Institute
defines pilling as “the formation of small
tangles of fibres or balls on the surface of
fabric”. Pilling changes the appearance and
texture of the fabric.
Pilling appearance
Measurement of Pills
• The measurement of pills is in two stages.
• The first stage is the formation of pills by
means of laboratory-test apparatus.
• The second stage is the evaluation of pills
(subjectively by experts)
• Objective methods characterize pills in
terms of their number, weight and size. The
combination of counting the pills as a
measurement of pilling propensity and
weighting the number with respect to their
size is quite complex.
Pilling
More definition
• Pilling is a condition that arises in wear due to the
formation of little “pills” of entangled fibre clinging to
the fabric surface giving it an unsightly appearance.
• Pills are formed by a rubbing action on loose fibres which
are present on the fabric surface.
• Pilling was originally a fault found mainly in knitted
woolen goods made from soft twisted yarns.
• The introduction of man-made fibres into clothing has
aggravated its seriousness.
• The explanation for this is that these fibres are
stronger than wool so that the pills remain attached to
the surface rather than breaking away as would be the
case with wool.
Pilling Tester
• Random Tumble Pilling Tester
• ICI pilling box tester
– 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.
• Martindale Abrasion Tester (for both
knitted and woven fabric)
Atlas Random Tumble
Pilling Tester
ICI Pilling Box
Factors affecting pilling
A) Yarn type
• Spinning technique affects the pilling.
• Ring spun yarn is, in general, more resistance to
pilling than open-end-spun yarn.
• Ring spinning gives a better fibre control (fibre
orientation) than open-ended spinning (loose and
random arrangement) results in lower pilling.
• Air-jet spun yarns, however, give a much better
pilling control than both ring and open-ended
spinning.
• The best pill-resistant is air-jet spun yarn, followed
by ring spun yarn and open-ended yarn
B) Other yarn variables
1. Yarn count
1. In a study of knitted fabric, pilling is observed
to be less for yarns of finer counts.
2. This parameter is also found to be less for
fabric produced with higher machine gauge
2. Yarn Twist
1. The higher the twist in yarn, the less is the
pilling because of the compactness and because
there is less protruding fibre in the yarn.
2. Doubled yarn gives less pilling than singles yarn
C) Fabric type
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Knitted fabrics tend to pill more readily than woven
fabrics.
Since knitted constructions are composed of a series
of loops, a greater amount of yarn surface is exposed,
making them more susceptible to abrasion in wear.
Moreover, knitted fabrics are more often constructed
of low-twist yarns made of staple fibres to give a soft,
bulky feel and appearnace.
Again, the staple fibres have a greater chance of
working their way to the surface of fabric to form
pilling
Dry relaxed knitted fabrics made from yarns with a
higher proportion of acrylic fibres exhibit a greater
pilling tendency. The incidence of pilling considerably
reduces with an increase in twist and the tightness
factor after full-relaxation treatments
E) Weave Structure
• The twill-woven fabric gives substantially more pills
than the plain-woven fabric.
• The greater number of interlacings and shortlengths in the plain-woven fabric probably reduce
the opportunity for the free ends to emerge on the
fabric surface and thus reduce pilling.
• The long floats in a twill weave expose longer
lengths of fibres to the surface and increase the
chance for pilling.
• This means that pilling can be reduced by the
correct choice of weave
Discussion
• What is pilling?
• What are the effects of yarn count
and yarn twist on pilling?
• Why knitted fabric tends to pill more
often than woven fabric?
• Which woven structure will cause more
pilling, plain weave or twill weave?
Reference
• Pilling by J.O. Ukponmwan
• Textile Progress, Vol 28, No. 3 by
Textile Institute (TS1300 .T515, V.
28, No. 3)
• Physical testing of textiles, B.P.
Saville, the Textile Institute