Pilling
Pilling:
Pilling is formation of little balls of fibers (pills) on
the surface of a fabric which is caused by abrasion in wear.
Pilling is the tendency of fibers to come loose from a
fabric surface and form balled particles of fiber.
Causes
of Pilling:
a.
Due to wear and abrasion.
b.
Due to rubbing action of fabric with particular
parts of garments and body.
c.
Due to soft twisted yarn.
d.
Due to excess short fibres.
e.
Due to migration of fibres from constituent yarn
in fabric.
f.
Due to protruding fibre / yarn hairiness.
g.
Due to heat in case of thermoplastic fibres.
Reduction OR Minimizing pilling:
a.
By using high twisted yarn.
b.
By brushing and cropping of the fabric surface
to remove loose fibre ends.
c.
By using singeing process to reduce yarn
hairiness, longer fibres.
d.
By using anti pilling technique.
e.
By special chemical treatment such as adhesive, anti-rubbing
agent.
f.
By reducing migration of fibres by means of Air
Jet spinning process.
g.
By increasing inter-fibre friction.
h.
By increasing linear density of the fibre.
i.
By using a high number of threads per unit
length.
Reduction
or prevention of pilling:
As pill form due to
migration of fibers from the constituent yarns in the fabric, it follows that
the reduction or prevention of pilling may be affected by reducing this
migratory tendency. The method used include the use of higher twist factors for
the yarns, the brushing and cropping of the fabric surface, by using airjet
spinning. Pilling is reduced by increasing the Nylon filament denier. Whatever
anti-pilling technique is used, the fabric must not lose its desirable handle
or other qualities.
Pilling
test:
1. Martindale Abrasion Tester
2. The H.A.T.R.A(Hosiery and allied trades research
association)
3. The I.C.I(Imperial Chemical Industry) pilling box test
4. The Du pont random pilling test
ICI
BOX PILLING TEST:
1.
For this test four specimens each 5 inch X 5
inch are cut from the fabric.
2.
A seam allowance of 12mm is marked on the back
of each square. In two of the samples the seam is marked parallel to the warp
direction and in the other two parallel to the weft direction.
3.
The samples are then folded face to face and a
seam is sewn on the marked line.
4.
This gives two specimens with the seam parallel
to the warp and two with the seam parallel to the weft.
5.
Each specimen is turned inside out and 6mm cut
off each end of it thus removing any sewing distortion.
6.
The
fabric tubes made are then mounted on rubber tubes so that the length of tube
showing at each end is the same. Each of the loose ends is taped with poly
(vinyl chloride) (PVC) tape so that 6mm of the rubber tube is left exposed as
shown in Figure.
7.
All four specimens are then placed in one pilling
box.
8.
The samples are then tumbled together in a
cork-lined box as shown in Figure.
9.
The usual
number of revolutions used in the test is 18,000 which take 5 hrs.
Assessment
The specimens are removed from the tubes and viewed using
oblique lighting. The samples are then given a rating of between 1 to 5.
