Faults in Knit Dyed Fabric
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Faults in Knit Dyed Fabric
Name : MAZADUL HASAN SHESHIRID: 2010000400008Batch: 13th Batch (Session 2009-2013)Department: Wet Processing Technology Email: [email protected]: www. Textilelab.blogspot.com Southeast UniversityDepartment of Textile Engineering
PREPARED BY ©right
Knitting faults
Yarn dust
Causes of faults: - Fly yarn/ foreign fiber
Remedies: - Proper air suction
Set-up
Causes of faults: - For badly needle break Yarn break
Remedies: - Remove bad needle Maintain proper tension
Loop mark
Causes of faults: - Defective needle Not properly needle
latch work
Remedies: - Change new needle By clean needle latch,
hook
Needle break
Causes of faults: - High yarn tension Bad setting of the yarn
feeders Old and worn out needle
set
Remedies: - Ensure uniform and right
yarn tension on the feeders
Keep the recommended gap between the yarn feeders and the needles
Periodically change complete set of needles
Oil spot
Causes of faults: - Due to contact with oil or
grease covered exposed m/c parts
Careless handling could be another cause
Remedies: - Use of strong knitting oil
which can be removed After every process, if
possible check filter and clean it
Thick place
Causes of faults: - Different yarn count Use unmatured fiber
Remedies: - Select matured fiber Check /indentify the
yarn thick/thin place
Mix yarn/Lot mix
Causes of faults: - Unawareness of
operator
Remedies: - Awareness in
production
Hole
Causes of faults: - Holes are the results of yarn
breakage Yarn tension too high Presence of knots in yarn If the yarn count is not
correct
Remedies: - Yarn strength must be
sufficient Maintain proper tension Knots should be given
properly Use proper count of yarn
Lycra out
Causes of faults: - Yarn tension too high Lycra guide roller block
or jam Needle not properly work
Remedies: - Maintain proper yarn
tension Ensure smooth running
of guide roller Change defective needle
Yarn contamination
Causes of faults: - Presence of dead fibers
and other foreign materials Presence of the foreign
materials, in the stable fiber mixing
Remedies: - Use rich fiber mixing for
the yarns Segregate the knitting m/c
with mosquito nets to prevent the fibers flying from neighboring
Miss yarn
Causes of faults: - Yarn break Positive feeder jam Excessive needle tension Weak yarn
Remedies: - Yarn strength must be
sufficient Smooth running of feeder Proper needle tension
Tara fault (Star)
Causes of faults: - For high r.p.m of m/c
cylinder One part dyeing
Remedies: - Maintain proper r.p.m of
m/c cylinder Range should be upto
23
Dyeing faults
Uneven dyeing
Causes of faults: - Inadequate scouring of the
grey fabric Correct pH value not
maintained Water hardness Improper neutralization Improper migration
Remedies: - Scour the grey fabric
thoroughly, to remove all the impurities from the fabric
Maintain the correct pH value Maintain water hardness Proper neutralization Proper migration
Uneven dyeing
Causes of faults: - Improper neutralization Improper dyes dosing Improper soda dosing Improper migration Improper leveling agents
Remedies: - Proper neutralization Proper dyes dosing Proper soda dosing Proper migration Proper leveling agents
Uneven dyeing
Causes of faults: - Dyeing m/c stoppage, due to
power failure or the fabric entanglement in the dyeing m/c
Correct pH value not maintained
Improper leveling agent Water hardness
Remedies: - Use a power back up for the
dyeing operation to be completed uninterrupted
Maintain correct pH value Use appropriate leveling agents Maintain water hardness
Dye spots
Causes of faults: - Colored spots due to
dye deposits on the m/c
Remedies: - Pay attention to
cleanness in the m/c
Pilling
Causes of faults: - Due to friction of fabric Poor yarn quality
Remedies: - Need good enzyme
treatment By using combed yarn
Uneven dyeing
Causes of faults: - Improper migration Improper neutralization Inadequate scouring of
the grey fabric
Remedies: - Scouring the grey fabric
thoroughly Proper migration Proper neutralization
Soda spot
Causes of faults: - Improper dosing of soda
Remedies: - Proper dosing of soda
Finishing fault of knit dyeing fabric
Uneven
Causes of faults: - Unstable dye dispersion Dispersing agent not
enough Wrong temperature
Remedies: - Select dyes with better
dispersion stability Proper temperature
maintained
Skew
Causes of faults: - Over width for this
fabric
Remedies: - By using weft
straightening device Maintain proper width
Slitting fault
Causes of faults: - It is causes due to
operator carelessness
Remedies: - Operators have to slit
fabric through slitting mark
Uneven brushing
Causes of faults: - Not proper soft Roller pins problem
Remedies: - Use softener Check pins
Crease mark
Causes of faults: - Improper motion of
padder Improper fabric
movement
Remedies: - Proper motion of padder Ensure smooth running
of fabric Use anti-creasing agents
Unwanted mark
Causes of faults: - Due to contact with oil
or grease covered exposed m/c parts
Careless handling could be another cause
Remedies: - Use of strong oil which
can be removed Proper handling should
be taken
Oil mark
Causes of faults: - Due to contact with oil
or grease covered exposed m/c parts
Careless handling could be another cause
Remedies: - Use of strong oil which
can be removed After every process, if
possible check filter and clean it
Silicon spot
Causes of faults: - Long time deposit of
solution Improper mixing of the
silicon
Remedies: - Proper mixing of the
silicon Use the right silicon Maintain the correct pH
value, before application
Silicon mark & Burn effect
Causes of faults: - Long time deposit of solution Improper mixing For over or high temperature
this burn effect is visible Twice stenter
Remedies: - Proper mixing Select suitable silicon Maintain correct temperature
Line mark
Causes of faults: - This mark are caused
due to the excessive pressure of the roller
Remedies: - Pressure of roller should
be maintained Take care of fabric
Burning effect
Causes of faults: - For wrong temperature Unawareness of
operator
Remedies: - Maintained proper
temperature By using experienced
manpower
Chemical spot
Causes of faults: - Improper mixing of
chemical Weak chemical Unawareness of operator
Remedies: - Proper mixing of chemical Use appropriate chemical By using experienced
manpower
Uneven brushing
Causes of faults: - Too much pressure of
the cylinder roller is the causes
Remedies: - Operator should take
care when fabric is running
Uniform motion R.P.M should maintained
Uneven brushing
Causes of faults: - Too much pressure of
the cylinder roller is the causes
Remedies: - Operator should take
care when fabric is running
Uniform motion R.P.M should maintained
Sewding fault
Causes of faults: - Wrong m/c set up Over speed /r.p.m Displace of pin
Remedies: - Installed proper m/c set
up Maintain correct
cylinder speed Check and proper
placement of pin
Unwanted mark
Causes of faults: - Due to contact with iron
rust from m/c parts If fabric wet long time Unclean roller or padder
Remedies: - Try to clean m/c parts Keep fabric dry Clean roller and padder
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