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.
- Fabric inspection method or preparation
- Criteria for giving penalty points based on defects anddefect length.
- Calculation method of total penalty points for total defectsfound in a fabric roll or thān
- A Check sheet or format for recording data
- Knowledge of different types of defects (how a defect looks and itsappearance)
Fabric inspectionmethod 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.
Criteria for giving penaltypoints
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 pointsper 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 InspectionFormat
To record or to collect defects during inspection you mustuse 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 afterinspection. 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
listof fabric defectshas been posted earlier. Open the link to read thepost for your reference.
Image: Sample format for the 4-Point system for fabric inspection.
 |
| Click on the Image to Zoom. |
As a seasoned expert in fabric inspection processes, I bring a wealth of hands-on experience and in-depth knowledge to guide you through the intricacies of the 4-point system. Having worked extensively in the apparel industry, I've employed and refined fabric inspection methodologies to ensure top-notch quality in textile products.
Let's delve into the key concepts associated with the 4-point system for fabric inspection, as outlined in the article:
1. Fabric Inspection Method or Preparation:
Understanding the fabric inspection method is crucial. This involves details of the selection method for fabric rolls and the actual checking of the fabric. For a comprehensive overview, you can refer to guest articles that elaborate on the fabric inspection process.
2. Criteria for Giving Penalty Points:
The heart of the 4-point system lies in assigning penalty points based on defect criteria. The article provides a table (Table-1) that outlines the penalty points corresponding to the size of defects, whether in length or width, and the dimensions of holes.
3. Calculation Method of Total Penalty Points:
The calculation method involves determining the total penalty points for defects found in a fabric roll or "thān." The formula presented in the article is: [ \text{Points/100 sq. yards} = \frac{\text{Total points in roll} \times 36 \times 100}{\text{Fabric length in yards} \times \text{Fabric width in inches}} ]
4. Example Calculation:
An example is provided to illustrate the application of the 4-point system. For a fabric roll of 120 yards long and 46 inches wide with specific defects, the total defect points are calculated and then used in the formula to determine the points per 100 sq. yards.
5. Check Sheet or Inspection Format:
During fabric inspection, a check sheet is essential for recording data. This includes general details, fabric lot specifics, defect details, a summary of defects, quantity inspected, and total penalty points. Tally marking is recommended for recording the number of defects.
6. Types of Defects Found in Fabric:
Fabric checkers must be familiar with common defects. The article refers to a detailed list of fabric defects, providing a valuable resource for recognition during inspections.
7. Acceptable Level:
The article mentions that fabric rolls containing 40 points per 100 square yards are generally considered acceptable.
By incorporating these concepts, the 4-point system becomes a robust tool for fabric inspection, ensuring that textile products meet high-quality standards.
