How to use 4 Point System in Fabric Inspection?

Question: How to use the 4-point system for fabric inspection? Provide me an example with calculation. ... asked by Saravanan

Fabric inspection machine

Answer:

4 Point system for fabric inspection is widely used in the apparel industry for fabric quality inspection. To use this system you have to know the following things.
  1. Fabric inspection method or preparation
  2. Criteria for giving penalty points based on defects and defect length.   
  3. Calculation method of total penalty points for total defects found in a fabric roll or thān
  4. A Check sheet or format for recording data
  5. Knowledge of different types of defects (how a defect looks and its appearance)


Fabric inspection method or preparation

Details of the selection method of fabric rolls and checking of the fabric have been explained in our previous post. 

Please read one of our guest articles for the method of fabric inspection. 
Essential Fabric Quality Reports for Bulk Cutting Approval of Fabrics


Criteria for giving penalty points

In the following table, the penalty evaluation points have been given for the different lengths of fabric defects and dimensions of holes.

Table -1

Size of Defect

Penalty Points
Length of defects in fabric (either length or width)
Defects up to 3 inches
1
Defects > 3 inches < 6 inches
2
Defects > 6 inches < 9 inches
3
Defects > 9 inches
4
Holes and openings(largest dimension)
1 inch or less
2
Over 1 inch
4


Calculation of total points per yard

In 4 point system, fabric quality is evaluated by unit points/100 sq. yds.  

Points / 100 sq. yd. = (Total points in roll * 36 * 100)/ (Fabric length in yards * Fabric width in inches)

Normally fabric rolls containing 40 points per 100 square yards are acceptable.



Also Read: 4 Point System - Acceptable Level

Example: A fabric roll 120 yards long and 46 inches wide contains the following defects.

4 defects up to 3 inch length
3 defects from 3 to 6 inch length
2 defects from 6 to 9 inch length
1 defect over 9 inch length
1 hole over 1 inch
4 x 1
3 X 2
2 X 3
1 X 4
1 X 4
4 points
6 points
6 points
4 points
4 points
Total defect points
24 Points
Therefore,
Points/ 100 sq. yards
= (24 X 3600)/(120 X 46)
= 15.652 points

Checksheet or Inspection Format

To record or to collect defects during inspection you must use a simple check sheet. A check sheet includes general details, details of the fabric lot, fabric defects according to their sizes, a summary of fabric defects, quantity inspected, and total penalty points, and result of the fabric lot after inspection. Use tally marking to record the number of defects found during checking. A sample 4-point system fabric inspection format has been attached at the bottom.


Types of defects found in fabric

Fabric checkers should know common defects found in fabrics and they must recognize defects on the fabric at the time of fabric inspection. A detailed list of fabric defects has been posted earlier. Open the link to read the post for your reference.

Image: Sample format for the 4-Point system for fabric inspection. 
Click on the Image to Zoom.

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