4 Point Inspection System
Prof. Ravikumar N. Purohit
D.K.T.E. Society’s Textile and Engineering Institute, Ichalkaranji-416115
What is 4 Point Inspection?
4point inspection system is most widely used system for fabric inspection method. This system is used in weaving after fabric making and in garment industries in fabric department.
Objective behind 4 point inspection in both the cases is to analyze fabric quality.
If fabric contains very less faults then weaver can sell this fabric at higher rate as fabric is having good quality. If buyer is already fixed then weaver will come to know whether fabric which has been produced satisfies customer requirement or not.
For Garment industry
To decide whether fabric roll is acceptable for next process or they should reject the roll and lot.
|4 Point Inspection System|
Process of 4 Point Inspection
To analyze the fabric after fabric making
- The roll is taken on inspection machine as shown in the image
- A standard sheet as per company format is given to the operator
- Operator fills the required details of fabric such as sort, color, actual width and actual length.
- Defects in both warp as well as weft directions will be assigned and marking of defects is done with the chalk or sticker
- Points under the following criteria with respect to length has to be given. Following chart of 1-4 points marking is given.
- Total points has to be summarized with actual length and actual width.
- Finally calculation is to be done which will give total number of fabric defects per 100 square yard.
How Points are Assigned?
|Defect Range||Points Evaluation|
|Up to 3 inches||1 Point|
|Greater than 3 inches and less than 6 inches||2 Points|
|Greater than 6 inches and less than 9 inches||3 Points|
|Greater than 9 inches||4 Points|
|Hole in the fabric less than 1 inch||2 Points|
|Hole in the fabric greater than 1 inch||4 Points|
Individual Roll Points
The following formula is used to determine the point count for each roll.
Formula Points per 100 square yard
= (Total points found in roll * 36*100) / (Inspected length in yard * Fabric width (inches))
Decision for roll acceptance or rejection for inspected roll length of 100 meter with width 50 inches and it contains following defects.
|5 defects less than 3 inches||5*1= 5 points|
|4 defects between 3-6 inches||4*2= 8 points|
|2 defects between 6-9 inches||2*3= 6 points|
|2 defect on full with in weft||2*4 =8 points|
Total points are: (5+8+6+8 =27 points)
Inspected length is 100 meter: 100*1.093= 109.3 yard
Width in inches: 50
As per formula total points per 100 square yard =
Now here comes a question- Should we reject the roll or accept the roll.
Acceptance or Rejection of Roll
So the conclusion of Acceptance or rejection of roll purely depends on company policy. What criteria they have like some companies follow 40 points means if they have less than 40 defects per 100 square yard then they will accept this roll. While some companies follow 24 points. So here in both the cases fabric is acceptable.