Silk fabric defects

PRESENTED BY
DR.B.SUJATHA
DEPARTMENT OF
SERICULTURE
S.K.UNIVERSITY
ANANTAPURAMU (A.P)

 INTRODUCTION :
 In textile industry, woven fabric is produced by
interlacing warp and weft yarn. Faulty woven
fabrics hampers the total quality of woven
garments such as sarees, shirt, jacket etc.,
 A Fabric Defect is any abnormality in the
Fabric that hinders its acceptability by the Due
to the increasing demand for quality fabrics,
high quality requirements are today greater
since customer has become more aware of
poor quality problems.

 To avoid rejection of fabric, it is necessary
to avoid defects.
 Price of fabric is reduced by 45%-65% due to
the presence of defects.
 During manufacturing woven fabric in the
weaving loom, defects are produced. Some
of these defects are visible, while others are
not.
 Again some defects may be rectified during
weaving and after weaving, while others are
not.
 Though the fabric manufacturers try to make
the fabric fault free, somehow different kind
of unwanted flaws is found in the fabrics.

Causes: 1. Faults in Raw silk
 2. Faults in Preparatory
process
 3. Faults in Weaving
 4. faults in Wet processing

1. Warp way defects
2. Weft way defects

A) Loose warp (Slack end)
B) Tight warp or end
C) Broken ends or missing ends
D) Warp streaks/warp stripes / Cracks between
stripes
E) Wrong/miss drawing
F) Reed mark
G) Warp floats
H) Double end


 Due to 1 or more
ends getting loose
and forming loop.
Reasons:
 wrong replacement
of broken ends
 Wrong adjustment of
tension

 Due to tight tension
missing of yarn or
broken at any place
across the width of
the fabric

C) Broken ends or
missing ends :
 The fabric is
characterised by
a gap parallel to
the warp.
 The number of
ends may be
missing one or
more on fabric

D) Warp streaks/warp stripes / Cracks
between stripes :
 Unevenness or mix-up or wrong replacement of
warp yarn.
 A crack seen along the length of the fabric
between the stripes woven with different weaves.

 Mistakes in drawing in.
 Incorrect positions of
ends in the fabric
causing considerable
damage in fabrics with
woven design/stripes.
Causes
 Faulty drawing-in of
beam.
 Faulty drawing-in of
broken ends by the
weaver.

F) Reed mark:
 Warp streaks spreading through out the
fabric and is caused by wrong number of
ends due to bad reeds.

G) Warp floats :
 Entanglements at
the time of
shedding due to
knots or broken
ends, slugs, poor
cohesion of raw silk
causes warp
threads floating.

 H) Double end :
More than one end working
in a heddle eye without the
adjacent end missing.
Causes
Sticky ends on weavers
beam.
Wrong drawing-in of ends
through heddle eyes.

A) Thick place or thin place
B) Crack or open set mark
C) Weft bars
D) Loose pick or snarl / Sloughing off
E) Tight pick
F)Broken pattern
G) Broken pick
H) Oil or Stain
I) Wavy defects

A). Thick place or
thin place :
 An abnormally
thick place in the
yarn finally
appearing in the
fabric.
 Weft bars differing
in appearance and
repeating several
times along the
fabric.
Causes
 Irregular let-off.
 Faulty take-up.

 Space between weft threads .
 A higher pick density than the
normal is referred to as starting
mark while a lower pick density
is referred to as crack.
 Causes
 Improper letting back of the fell
of the fabric.
 Improper lifting of the dead
weights on let-off motion while
adjusting the warp tension.
 Faulty functioning of anti-crack
and weft fork mechanisms.

 Stripes along weft due to
denier variation and where
there is a mix up of
different yarns.

 Weft way bands which are
clearly distinguished from
the rest of the portion of
the fabric.
 The bars may be restricted
for a particular length of
fabric or may repeat at
fixed intervals.

Causes of Weft bars
 Mixing of weft of – different counts,
different twist levels, different directions
of doubling twist and different brightness
levels especially in filaments.
 Mixing of spun blended yarns produced
from synthetic fibers of different merge
numbers.
 Manufacturing defect in filaments like
variation in denier.

 Thick bunches of yarn
are woven into the fabric
in the weft direction due
to slipping off of coils of
yarn from the pirn during
weaving.
 Causes
 Formation of loops due
to fault in pirn or shuttle.
 Improper package
characteristics.
 Softly wound pirns.
 Harsh picking and/or
poor shuttle checking.
 Poor humidity conditions
during the storage of
pirns.

 Shining is
formed due to
high tension
applied while
preparing the
weft.

 Restricted to
fabric woven
with patterns on
drop box looms.
It occurs either
when the
sequence of weft
colors to be put
is disturbed or
when the width
of color band is
affected.

Causes of Broken pattern
 Improper adjustment of pattern cards or
lattices.
 Weaver neglecting to adjust the pattern
chain before restarting the loom after
mending a break or a crack.
 Inserting pick in a wrong shed after
mending a weft break.

 Weft is inserted only
for a portion of a pick.
 Causes
 Weft break or weft
exhaustion on
ordinary looms.
 Weft break or
improper size of
bunch on auto-pirns.
 Improper functioning
of weft fork.
 Weft change effected
through weft fork
mechanism on
automatic looms.

 These are spot
defects of oil,
rust, grease or
other stain found
on the fabric
 Cause:
 Improper oiling
or greasing of
looms
 Oil stained take-
up roller

 Crowded area
where thin and
thick places are
alternate like
wave.

Silk fabric defects

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