Sunday, May 5, 2013

Fabric faults produced during weaving & knitting production

Weaving fault:
Warp way defect:
I. Warp stitching : Occurred due to want of interlacement between warp & weft yarn which happen:
   Ø If the warp threads of one shed goes to another.
   Ø Faulty dobby or jacquard mechanism.
   Ø Warp yarn if loose.
   Ø Height of the harness card if not equal.
   Ø Warp is not properly sized.

a) Long float: causes due to
   Ø If the warp yarn does not take part in interlacement.
   Ø Tappet is not properly tied.
   Ø Peg if dobby displaced.
   Ø Jacquard harness or cord cutting if defective.
   Ø Worn out Reed if used.

b) Wrong warp threads: due to drafting & lifting.
Missing warp: causes due to:
   Ø Wrong denting.
   Ø Broken warp yarn in the beam.
   Ø Out of order warp stop motion.

d) Double warp: warp way marks on the fabric due to:
   Ø Wrong reed count used.
   Ø Wrong denting in the reed.

e) Loose warp: Causes due to
   Ø Loose warp exist on the beam in loop form.
   Ø Yarn tension in the dropper.
   Ø Size picks up unequal.

f) Knot in the warp yarn: If there are any knots in warp yarns.

g) Selvedge effect: Causes due to :
   Ø If the body and selvedge warp yarns tension is unequal.
   Ø If the reed space is greater but the width of the fabric is les.
   Ø Sharp temple ring spikes.

h) Weft cut at the selvedge: due to
   Ø Absent of weft yarn in the selvedge
   Ø Defective ring temple.
   Ø If the temple not properly set.

i) Temple mark: Mark on the selvedge of the fabric due to: light fabric if course temple is used.

Weft way fault:
1. Miss pick or broken pick:- Causes Due to
   Ø Broken pick.
   Ø Yarn of pirnoooo is finish.
   Ø If weft yarn breaks at the middle.
   Ø Picking much uniform occurred by empty shuttle.

2. Broken design: If the lifting mechanism is defective.

3. Thick & thin place which is called bar on the fabric.

4. Shuttle mark:
   Ø Shuttle flies.
   Ø Shuttle box is not properly set.

Defective of knitted goods to be unspected:

1. Broken ends: If the yarn breaks, holes create in the fabric.
   Ø During loop formation if the yarn previously broken in the needle.

2. Drop stitch:
   Ø Due to defective needle.
   Ø Yarn feeder not properly set.
   Ø Wrong take up mechanism.
   Ø Stitching tension if not proper.

3. Slugging.
   Ø Only occurs in continuous filament yarn.
   Ø Occurs due to mechanical strain in the next process stages.

4. Tuck & doable stitch: Occurs due to badly oooo or knitted loop. It results the formation small brads or thick & thin places in large ascoooo.

5. Bunching up: Visible knots in the fabric eyes known as beads.

6. Vertical stripe: Vertically shown streaks on the Wales which causes due to:
   Ø Gauge is not done according to count.
   Ø Stitch size.
   Ø Course density.

7. Horizontal stripe:
unevenness along the course direction.
   Ø Yarn feeder if not properly set.
   Ø Tension if not uniform.
Wish You Good Luck..................................
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