Textiles Quality Management (QTEX-4021)

Online Class Materials

Faults of sizing:

1. Size spots: Size material should be added gradually to the mixing tank for good mixing. If it
is added at once, spots are appeared on the yarn.
2. Repeating warp streaks:
This defect is due to uneven tension in the pre-beam.

3. Shin nery:
This defect due to the friction between the yarn and drying cylinder.

4. Sandy warp:
Due to not crushed or grind the size material properly.

5. Ridge Beam:
This fault occurs due to uneven distribution of yarn in wraith.

6. Hard sizing: If the size materials are applied too much, the size becomes hard which causes
hard sizing.
7. Over dried warp:
Under drying à Bacteria form à Yarn breakage.

Over drying à Hard sizing.

Over dried warp may be produced due to –

 Lower speed of warp sheet passing through drying roller.

 High stem pressure
 Faulty auto stop motion.
8. Size dropping:
This defect due to not optimum the viscosity of the size solution.

9. Size stitching: Due to improper drying after sizing.

10. Uneven sizing:
(i) Due to over or under sizing.

(ii) Due to over or under concentration of size liquor.

(iii) More or less temperature in drying section.

11. Over slashed warp: Over slashed warp may result due to-
 High concentration of size liquor
  Lower tension on yarn
 Lower yarn passing speed and low temperature of squeezing roller.

12. Under slashed warp: Under slashed warp may result due to-
 Very dilute size liquor
 High tension on warp
 Wrong level of size in size box.
 High speed of yarn passing
 High pressure of squeezing roller.

Process control technique in winding:

In winding section the following points should maintained properly-

1. Appropriate tension (low or high)

2. Freeness from different count mixing
3. Mechanical fault free winding machine e.g. free from defective traversing motion ,fault
free yarn guide, clean yarn guide(oil, grease free)
4. Proper yarn knotting system(e.g. fully automatic on manual)

Defects of woven fabrics:

1. Bar
2. Box mark
3. Broken pattern
4. Broken pick
5. Cracks
6. Cut weft
7. Defective selvedges
8. Floats stitches
9. fuzzy
10. hang pick
11. Missing ends /ends out
12. Reed marks
13. Shuttle marks
14. Stains
15. Uneven cloth
1. Bar: It is a band running across the full width of cloth due to difference in appearance
from its adjacent surface. This term covers a number of specific defect as below-
 Pick bar-due to difference in pick spacing.
 Starting mark-due to restarting weaving after unweaving, pick finding, prolonged loom
stoppage etc.
 Tension bar/shiner-due to difference in weft tensions.
 Weft bar-due to difference in material count, twist, luster. Color or shade of adjacent
groups of weft yarns.
2. Box mark: Box mark is a widthwise fine line showing stained or injured weft due to the
rubbing of shuttle when it rebounds. The causes of box marks are-
 Dirty box
 Shuttle riding over the weft
 Dirty shuttle
 Weft flying about too freely
 Dirty picking sticks
3. Broken pattern: This defect may be due to wrong drawing of threads, inserting of the
pick in wrong shed, incorrect lifting of warp threads etc.
4. Broken pick: A pick missing from a portion of the width of the fabric due to rough
shuttle eyes, poor winding, weft yarn breakage, improper pirn insertion in the shuttle
etc.
5. Cracks: It si a narrow streak along the weft due to pronounced opening between two
adjacent yarns. A take up motion which is a sticking may also produce crack in fabric.
6. Cut weft: This defect is caused by using weak weft a strong warp. It shows as a pin hole.
7. Defective selvedges: There may be various types of defective selvedges as –
 Curled selvedge-due to incorrect balance of cloth structures between body and
selvedges.
 Cut selvedges-due to selvedge sticking to the emery cloth.
 Loppy selvedges- due to selvedge ends have worn.
 Pulled in selvedges-due to isolated tight picks.
 Slack selvedges-due to tension variation between body and selvedges.
 Tight selvedges-due to incorrect balance of structure between the body and the
selvedges.
 Uneven selvedges-due to variation in weft tension.
8. Floats stitches: A place where warp and weft yarns escape the required interlacement.
Main causes are-entanglements in warp and weft threads, improper warp stop motion,
static electricity generation etc.
9. Fuzzy: This is the fibrous appearance of the cloth due to presence of hairy or abraded
yarns.
10. Hang pick: A pick which is out of line for a short distance producing a triangular
shaped hole in the fabric. It is caused by too early shedding or too light weft tension.
 11. Missing ends /ends out: The most common end is characterized by a gap of one or more
warp ends in the fabric.
12. Reed marks: Due to this fault, cloth shows irregular spacing between groups of warp
yarns across the fabric width. The defect may be caused by damaged or defective reed or
too late shedding.
13. Shuttle marks: Width way marks due to abrasion of warp yarns by the shuttle.
14. Stains: Stains are major problems on woven fabric. Oil, greases, dust, soil, carbon
particles in the air, etc may cause stains. Most of the stains are caused by poor material
handling and careless of the workers. Certain stains can be removed by solvents.
15. Uneven cloth: In consistent diameters of weft can produce shady cloth, also occurs
when take-up motion is faulty. Broken ratchet wheel teeth may also produce faulty areas
on fabric.
Mechanical faults during weaving:

1. Reed marks
2. Shuttle flying out
3. Shuttle trapping in the warp
4. Loom banging of f
5. Loom stopping
6. Weft cutting
7. Bumping
8. Cops knocking-off or splitting.

1. Reed marks: Reed marks are caused by-

 Damaged reed.
 Bent reed wires
 Wrong denting etc
Remedies-

 Tappet dwell should be one- third of a pick or more

 The backrest is raised without altering the heald portion

2. Shuttle flying out: This is defect of the shuttle from its normal course of journey.
Causes:

 Defective shuttle
 Defective shuttle box
 Detect on race board
 Defect in the position of dwell.
 Slack warp
  Wrong warp
Remedies-

 Alternation must be given for the above causes

 The bottom line of shed must be resting on the race board.
3. Shuttle trapping in the warp: Signify breakage of a large number of warp ends.
Causes-

 Tight warp and wrong shed formation

 Large or broken shuttle
 Faulty protector blade
Remedies-

Careful setting of all the above points which cause the problem.

4. Loom banging off: a sudden stoppage of the loom by the application of a safety device.
Cause-

 Weak or short picking

 Faulty shedding
 Incorrect timing
 Faulty safety motion
 Shuttle strapping
Remedies-

Careful adjustment of the above setting points can remove the problem.

5. Loom stopping: The causes are-

 Broken warp
 Broken or finished(exhausted) weft in the pirn.
 Faulty shuttle movement
 Shuttle flying out or trapping in the shed

Remedies-

 Warp should be sized to make it strong.

 Proper adjustment of above motions.

6. Weft cutting: The causes are-

 Too tight box
 Narrow shuttle box
 Rough sley
 Ballooning of weft up and down when shuttle passes
  Early or late picking
 Temples come in contact of reed.
Remedies-

To set the above points carefully for proper adjustment.

7. Bumping: The causes are-

 Improper tension on warp.
 The roller not gripping the clot or turning properly.
 Warp turning round the warp beam.
Remedies-

To set above point in loom carefully

8. Cops knocking-off or splitting: The causes-

 Soft and slack wound cops
 Badly piecing of weft
 Rough handling of weft
 Uneven driving, shuttle trap etc.
Remedies-

To adjust the above points carefully and to build cop with proper size, shape and tension.

Quality checks applied for loom state:

The two aspects of fabric quality in the loom state are-

1. Meeting the following design specifications of the fabric-

 Type of fibres/yarns used
 Count and twist of warp and weft
 End and pick density(EPI and PPI)
 Weave and colour pattern.
 Width of fabric at the reed
 Grey width of fabric.
 Length of a cut.
2. Ensuring that fabrics are free from defects that originate during weaving. The fabrics
which is originated from loom should be free from-
 Stains
 Reed marks
 Shuttle marks
 Warp skip
 Floats stitches
 Missing ends
 Loose warp ends
 Defective selvedges
 Broken pick, cracks and box marks
 Bars, etc.