All
rolls are kept in front of the inspection m/c time to time and are inspected
over the grey inspection m/c visually in a pre-set speed against light.For any
major or minor faults like thick thin, contamination, fly, holes, oil lines,
needle lines, slubs, etc are recorded in grey inspection report to classify the
fabric based on the four point system.
Collar & cuff are inspected
visually under light box, any major & minor faulty collar/cuff like having wrong ply, hole,
needle lines, slubs, wrong design, first line problem etc properly counted and
recorded.
QUALITY ASSURANCE PROCEDURE:
Based
on the sequence of grey inspection, the inspector serially numbers each roll
ensuring that all rolls having the knit card with complete details of the roll.
a. After production of fabric rolls,
m/c operators cut them from the cloth or batch roller and they are carried to
inspection section by the helpers.
b. Almost four inspection workers are
for every shift to check the fabric rolls. For any kind of fault they are
checked thoroughly. Skilled inspectors find them and indicate them by the
scissors in some cases.
c. Quality is specified on the basis of
4-points system. Here is the point distribution for different kinds fault in
this system:-
FOUR-POINTS
SYSTEM
|
Size of defects
Penalty
|
Over 3 but not over 6
2 points
|
Over 3 but not over 9 3 points
|
Over
|
QUALITY CLASSIFICATION:
A B C REJECT
<40 41-60 64-80 80 above
LIST OF EQUIPMENTS:
In
this factory, this is the list of equipments to assure quality:-
1) Inspection m/c:(For all kinds of single
jersey as like as Lycra, Lacoste, Fleece and all kind of double jersey as like
as Rib, Interlock).
2) Scissors
3) Weight balance
4) GSM cutter
Fabric Faults:
Faults are very different in
nature and appearance & are often super-imposed. The source of faults could
be-
v
Faults in yarn
& the yarn package.
v
Yarn feeding
& yarn feeding regulator.
v
M/C setting &
pattern defects.
v
M/C maintenance.
v
Climate condition
in the knitting section.
The most common faults are-
1. Needle broken/breakage
2. Needle mark
3. Sinker mark
4. Belt fault
5. Lycra uneven tightness or looseness
6. Single yarn
7. Oil mark/oil stain
8. Wheel mark
9. Yarn contamination
10. Fly yarn/dead cotton
11. Lycra out
12. Star mark
13. Patta/stripe
14. Structure uneven
15. Loop/star/pin hole
16. Knot
17. VDQ pulley problem
18. Holes
19. Slub
20. Thick & thin
21. Yarn missing line
22. Grease stain
Causes & remedies
of fabric fault:
1. Needle broken:
Wales wise vertical line so
no loop is formed in vertical line.
Causes: Latch broken, Needle
broken.
Remedy: Select perfect needle
& perfect latch.
2. Needle mark:
Gap between two adjacent wales.
It creates wales wise.
Causes: Needle broken, bended
needle.
Remedy: selecting good
needle.
3.
Sinker mark:
It
creates vertical line in wale wise. It may be group wise single. It is same to
needle mark. By observing backside sinker mark will be observed.
Causes:
The most important cause is the lifetime of sinker. If sinker is used for
longtime then the sinker creates this fault.
1.
Broken sinker.
2.
Dirt in the trick wall.
Remedy:
1. Don’t use sinker for long time.
2.
Perfect as well as new sinker.
3.
Clearing the sinker.
4.
Oil mark:
It
may be created both wales & coarse wise. If wales wise formed then it
creates vertical stripe if coarse wise formed then creates horizontal stripe.
Causes:
1.
Broken needle.
2.
Broken sinker.
3.
Excess supply of oil.
Remedy:
1.By applying compressed yarn above the needle.
2.
Perfect needle & sinker.
5.
Wheel mark:
The
guard of positive feeder is not placed in perfect position. According to design
the guard must be up or down.
Remedy:
The guard of positive feeder must be in perfect position.
Displacement
of belt of wheel which is passed through positive feeder. Again foreign fiber
or fly fiber may be come to VDQ pulley. For this the dia of VDQ pulley may be
increased.
Causes:
1. Displacement of belt.
2.
Increasing dia of VDQ pulley.
Remedy:
Maintenance of VDQ pulley. Perfect control of wheel belt.
7.
Lycra tension:
Coarse
wise mark is seen.
Causes:
Tension of lycra is problem.
Remedy:
Should give proper tension of lycra.
8.
Lycra oil:
Lycra
missing in coarse wise. This problem is well understandable in white fabric. So
black is free from this problem.
Causes:
If needles are not take then this type of problem is seen.
Remedy:
Perfect feeding of yarn into needle.
9.
Single yarn: Some fabric need double
yarn in coarse wise direction such as flat back rib. But sometimes just single
yarn goes in coarse wise direction. This fault is known as single yarn fault.
Causes:
If needle is failed to feed the yarn.
Remedy:
Perfect feeding of yarn into needle. Another process is joining two different
yarn into same feeder & inactive another feeder.
10.
Yarn contamination:
Coarse
wise mark.
Causes:
1.Problem of bale management.
2.
So problem of yarn.
Remedy:
Proper bale management.
11.
Fly yarn:
Some
times flying yarn come & get mixed with main yarn. Thus these faults are
created.
Causes:
1.For improper m/c setting & management problem.
2.
Less care of worker.
Remedy:
1.Use separator from one m/c to another.
2. Worker must be careful.
CONTROL
OF FABRIC QUALITY:
Control
of the quality of the cloth being knitted is the knitter mechanic’s major
responsibility. Fabric sat –ups and m/c maintenance, although necessary, must
be put into their proper order of importers. To set-up a fabric and run it on a
well-maintained m/c, when its quality is questionable, is senseless.
The
mechanic must be able to diagnose a problem on a m/c and render an immediate
cure. To do this, he must have a through knowledge of what causes a defect in
fabric. When the cause is known, correction will soon follow.
QUALITY STANDARD:
Rejection criteria for body
& rib: Following table shows common body & rib faults and response by
grey inspection section.
|
No.
|
Faults
|
Response
|
|
1.
|
Needle marks
|
Major needle line is rejected.
|
|
2.
|
Stripe
|
Major needle line is rejected.
|
|
3.
|
Barre marks
|
Rejected
|
|
4.
|
Slubs
|
1 point
|
|
5.
|
Wrong design
|
Rejected
|
|
6.
|
Pin holes
|
1 point
|
|
7.
|
Fly & contamination
|
Acceptable for color but not for white.
|
|
8.
|
Sinker marks
|
Acceptable for color but not for white.
|
|
9.
|
Uneven tension
|
Discuss with manager.
|
|
10.
|
Missing yarn
|
Use 4 point.
|
|
11.
|
Crease line
|
Use 4 point
|
|
12.
|
Oil stripe/line
|
Discuss with manager.
|
|
13.
|
Thick-thin place
|
Rejected
|
|
14.
|
Mixed yarn
|
Discuss with manager.
|
Rejection criteria for collar
& cuff: Following table shows common collar & cuff faults and response
taken by grey inspection section.
|
No.
|
Faults
|
Response
|
|
1.
|
Wrong ply
|
Reject
|
|
2.
|
Hole
|
Reject
|
|
3.
|
Needle line
|
Reject
|
|
4.
|
Slubs
|
Reject
|
|
5.
|
Wrong design
|
Reject
|
|
6.
|
Wrong tripping
|
Reject
|
|
7.
|
Fly & contamination
|
Acceptable for color but not for white
|
|
8.
|
First round problem
|
Reject
|
|
9.
|
Uneven tension
|
Discuss with manager
|
|
10.
|
Missing yarn
|
Reject
|
|
11.
|
Crease line
|
Reject
|
|
12.
|
Rust line
|
Reject
|
|
13.
|
Oil stripe
|
Reject
|
|
14.
|
Thick-thin
|
Reject
|
|
15.
|
Wrong tube
|
Reject
|
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