What is 4 Point Inspection?

4 point inspection system is the most widely used system for fabric inspection methods. This system is used in weaving after fabric making and in garment industries in the fabric department.

Objective behind 4 point inspection in both the cases is to analyze fabric quality.

For weaving – 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.

Process of 4 Point Inspection

To analyze the fabric after fabric making

1. The roll is taken on inspection machine as shown in the image
2. A standard sheet as per company format is given to the operator
3. Operator fills the required details of fabric such as sort, color, actual width and actual length.
4. Defects in both warp as well as weft directions will be assigned and marking of defects is done with the chalk or sticker
5. Points under the following criteria with respect to length has to be given. Following chart of 1-4 points marking is given.
6. Total points has to be summarized with actual length and actual width.
7.  Finally calculation is to be done which will give total number of fabric defects per 100 square yard.

How Points are Assigned?

The following formula is used to determine the point count for each roll.

In garment factory Every roll of fabric will have different length and width. and generally they measure length in meters and width in inches.

This length and width is noted

Now to decide whether the fabric is acceptable or not. This fabric length and width should be converted to 100 square yards with the help of conversion. So any of the following formulas can be used to calculate fabric defects as per length and width. all formulas are the same just conversion is used with different units.

Example  

The decision for roll acceptance or rejection for inspected roll length of 100 meters 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 = (27*36*100)/(109.3*50)= 17.78

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.