Knitting Production Faults

1. Knit fabric defects
FP Technology
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2. Skewing
 Skewing or Bias : Line or design
running at slight angle across the cloth.
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4. Bowing or Twisting
 A line/design curve across the fabric .
 Reason : Faulty take up mechanism on
knitting machine
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5. Knots in knit fabric:
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6. Needle line
 Cause: due to defective needle, dirty needle
slot, improper lubrication of needle, needle
too tight or loose or bent needle
 Remedies: replacing defective needle,
remove the fibers in tricks, remove bent
needle, checking the needle sequence
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7. Hole
CAUSE REMEDIES
Due To Tight Knot Ensure uniform tension
Needle break due to slub Rate of yarn feed should be strictly
regulated
Due to high tension of yarn Eyelets, yarn guides, should not have
any fibres, fluff & wax etc
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8. Oil Mark
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Cause Remedy
Due to improper lubrication use oil as
lubricant
Fibres accumulated in needle tricks
Fibre and fluff accumulated in the
needle trick, which remain soaked
with oil
Remove all the needles and sinker of
machine and clean it.
Cleaning the grooves of cylinder and
dial of machine.

9. Slub ( Thick and thin place)
Cause Remedy
Uneven tension, uneven course, Mix
count, lot mix in blow room
Prevent count or lot mixing, maintain
uniform yarn tension
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10. Ladder ( Fabric Run )
 A run or ladder indicates a row
of dropped stitches in the wale.
 Reason: Yarn carrier are not
set properly.
 Stitch has been formed loosely
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11. Ladder :Wales collapse in straight line
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12. Barre / Shade bar
 A barre effect has the appearance of a stripe
with shaded edge .
 It is horizontal in weft knit fabric & vertical in
warp knit fabric.
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14. Reason of barre defect
 Due to Yarn / Due to machine
 Yarn related cause : Count variation, twist
variation, wrong yarn (size, color, blend ,twist
direction ) ,mixed yarn lots ,uneven oiling or
waxing ,improper conditioning .
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15. Reason of barre
 Machine related cause :
 Different stich length ,Improper tension
 Faulty dial & cylinder settings
 Improper threading
 Variation in take down or spreader system
 Machine vibration
 Dirt ,lint or yarn fragments in tricks ,needles
,sinkers or in cam system.
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16.  Variation in oil content
 Worn needles ,which generally produce
length direction streaks
 Uneven cylinder height
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17. Recommendation to minimize barre`
 Knit an entire dyeing lot in same knit
machine.
 Same spinning lot for entire fabric.
 Determine from quality control for same
quality of y.arn for entire lot
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18. Fly yarn contamination
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19. Fabric weight out of tolerance
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20. Dye Mark
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21. Stain ( excessive oil or dirt )
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22. Pin marks : poorly adjusted Stenter pin
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23. Spirality
 This is very common problem in single jersey
fabric.
 It is deformation of knit fabric due to yarn
twisting so that the vertical lines or wales are
no longer at right angle to horizontal lines
 It does not appear in rib or interlock fabrics.
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26. Problems due to Spirality
 In knitted garments the practical problem arise due to
spirallty.
 Shifting of seams, Mismatching, Patterning and sewing
difficulties
 These problem are often corrected by finishing steps
such as resin treatment,heat & steam ,so the wale line
are perpendicular to course line.
 Such setting are not stable ,and after repeated washing
cycle it normally reoccurs.
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27. Spirality
 It is caused by “ Unbalanced yarn”.
 Only option is to use replacement yarn
having balanced twist.(in finishing stage we
alleviate the problem but not permanently ).
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28.  Calculation
 Percentage change in spirality can be
represented as follows.
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29. Facing up
 It can be defined as unwanted surface fiber
leading to change in the appearance of the
garment.
 Knit fabric made from woolen yarns generally
are finished to create fuzzy / hairy surface and
during wear/abrasion the reverse effect is
sometime an issue.
 It can occur all over garment or in localized area.
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30. Facing up
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31. Facing up
 Reason : gradual withdrawal of fibers from
surface layer of yarns (migration) and can in
many cases lead to pilling.
 Facing up tend to occur abrasion resistance are
such as during tumble drying.
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32. Facing up
 The tendency to facing up depends upon several factor
,very similar with pilling
 Fiber length : short / broken fiber migrate easily.
 Fiber diameter: finer fiber tends to be shorter & thus
more likely to migrate.
 Yarn twist : low/irregular twist perform migration
 Cover factor: high density increase inter fiber friction
 Fabric softener: to much softener reduces inter fiber
friction and permit fiber migration .
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33. Cockling & loop distortion
 Cockling : An Irregular surface effect caused by loop
distortion.
 In general its appear in localized groups of distorted
knitted loops which have twisted out of the symmetrical
configuration .
 Generally on plain knit structure and specially in yarns
spun from animal fiber such as wool or mohair .
 Worsted yarn is more prone to cockling because no
milling treatment is carried out in finishing .
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34. Type of cockling
 1. Rib / plain interface cockling :It caused by
difference in the relaxed width of 2 structure.
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35. Panel edge cockling :
 Difference in the relaxed dimension of
neighboring structure.
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36. Random all over cockling :
 Almost always this can be assigned to using
unsuitable yarn,
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37. Reason for cockling
 Yarn count, twist play main role in yarn
irregularity.
 Steaming: it causes setting of yarn &
increased rigidity in case of shrink resist yarn.
 Crimp, dyeing method, cover factor.
 Remedy: Finer wool ,regular or even yarn,
avoid package dyeing, more crimp yarn can
remove cockling.
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38. Reason for cockling
 crimp, Method of dyeing
 Cover factor : lower the cover factor ,less
stable the resultant fabric and greater
possibility of cockling
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