Sunday, May 5, 2013

Most common Textile Inspection System

Piece goods inspection system:

In 1955 ten points piece goods evaluation was approved by the textile distribution & national federation of textiles. This system assigns penalty points to each defect.

Ten points system:- Filling defects penalty
Warp defects                 Penalty                       Full width                    10 points

10-30 ̎                          10 points                   5 ̎ ½ the width:                    5 ″

5-10 ̎                                 5 ″                                1-5 ̎ :-                        3 ″

1-5 ̎                                   3 ″                           up to 1 ̎ :-                        1 ″

Up to 1 ̎ 1 ″

Under the ten point system, a piece is graded a fixed if the total penalty point do not exceed the total yardage of the piece. A piece is graded a ‘second” if the total penalty points exceed the total yardage of the piece.

Four points system:

It is widely used in textiles. It is simple & easy to under stand. Inspection is done about 10% of the product in the shipment. This system has been applied by AAMA (American Apparel manufacturing association).

The four points system classifies classified defects as follow:

Size of defects                                             Penalty

3 ̎ or less                                                     1 point

Over 3 ̎not over 6 ̎                                       2 ″

Over 6 ̎but not over 9 ̎                                 3 ″

Over 9 ̎                                                       4 ″

A maximum 4 points is changed for one leniaroooo yard


Wish You Good Luck..................................
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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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AQL | Acceptable Quality Limits or Level

Major concept of Acceptable Quality Limit or Level:
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It is the allowable percent defective in a lot. This is introduced according to American military Standard of product inspection rules. There are generally 6 AQL used in textile which are as follows:- 1%,1.5%,2.5%,4%,6.5%,and 10%. Among them 2.5%,4%,6.5% and 10% are widely used and accepted according to price and type of garments.

Uses of AQL: In this system, sample is selected statistical method by using random sampling technique from a lot. After proper inspection along with the test results, the decision is taken, whether the lot will be accepted or rejected. Now a days this system is widely used in garments sector before the delivery. Although it is used from raw material to finished product also.

Acceptable sampling system consists of five parts:
1. Lot size
2. Sample size
3. AQL
4. Acceptable number
5. Reject number

Quality Inspection of factories:
According to JIS, Inspection is defined as “ to measure goods by some methods and by comparison with the results obtained against the criteria to judge whether the individual goods are defective or not

In textile factories the fabrics are inspected at the grey state, after pretreatment, coloration and finishing. After inspection the fabrics are classified according to their quality. Therefore fabrics are inspected to meet the requirements of the customers.

The fabrics are categorized in the following way depending upon the faults:

I. Fresh or First quality: Fabrics, hemming major, minor faults according to buyer specification and requirements.
II. Short length or two parts: It is a piece of cloth having a shorter length( More then 50 cm ). Jar parts become equal to fresh quality. Generally buyers gives (3-5)% discount value for the short length.
III. Seconds: Fabrics containing much objectionable minor defects and (8-15)% discount is allowed.
IV. Fents: Cut pieces of fabric measuring 90 cm or more but less than 150 cm lengths. For fents trade discount is (15-30) %.
V. Rags: Cut pieces of fabric measuring 25 c or more but less than 90 cm. This categories are sold by weight and realization is only about 50% of fresh fabric.
VI. Chilly: These are pieces of 25 cm length fabric less than this. These fabrics are bought & sold and trade discount generally given is ( 50-80).

Quality Parameters of Woven Fabrics to be inspected are as follows:

(1) Dimensional characteristics:
a) Length b) Width c) Thickness

(2) Weight of fabric:
a) Weight/unit area b) Weight/unit length

(3) Fabric strength & Elongation
a) Tensile strength b) Tearing c) Bursting

(4) Threads/inch:
a) Ends/inch
b) Picks/inch

(5) Yarn count
a) Warp count
b) Weft count

(6) Crimp
a) Warp count
b) Weft count

(7) Handle

a) Stiffness
b) Drape

(8) Crease resistance & crease recovery

(9) Air permeability

(10) Abrasion resistance and pilling.

(11) Shrinkages/Dimensional stability

(12) Different fastness properties:-
a) Washing fastness
b) Light fastness
c) Perspiration fastness
d) Rubbing

(13) Flameability

(14) Water resistance or absorption power

(15) Design of fabric

(16) Appearance of fabric

Quality parameters for knitted fabric to be inspected:


1. Strength & elongation
2. Course density
3. Wales density
4. Loop length
5. Deformation
6. GSM
7. Yarn count
8. Design

Wish You Good Luck..................................
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