The 4 point system is a widely used method in the apparel and textile industry to assess the fabric quality and also helps buyers and suppliers to understand, the quality of their fabric. The 4 point system evaluates and grades fabrics based on four criteria, which is why it is named the 4-point inspection system. In this article, we will explain the 4 Point System for Fabric Inspections and how it serves as a tool for quality control. but before going to explain it we must know the fabric faults then it will be easy to understand the standard operation procedure of the 4 point system.
How Does the 4 point system work:?
The 4 Point System helps classify defects based on their seriousness by giving demerits or penalty points.
This system is defined by ASTM D5430-93, a standard way to test fabric strength, published by the American Society for Testing and Materials (ASTM), and widely used in the textile industry.
In this system, defects in fabric’s warp/weft or course/wale directions are given penalty points based on their size:
Serial # | Defects | Points | |
|---|---|---|---|
1 | 0-3 inches | 1 | |
2 | 3-6 inches | 2 | |
3 | 6-9 inches | 3 | |
4 | Above 9 inches | 4 |
However, not all defects are treated equally. For example, holes dropped stitches, and torn selvages are automatically given 4 penalty points, regardless of their size. This ensures that no more than 4 points are given to any one linear meter or yard of fabric.
Calculation Formula of the 4 point system (Total points per Yard)
Using the 4 point system, fabric quality is determined by the number of points per 100 square yards.
Points per 100 square yards are calculated as follows =Penalty Points x 36 x 100 / Inspected yards x measured cuttable width in inches
Exercise:
A 140 yards long, 56 inches wide fabric roll was inspected, and the following defects were found:
Serial # | Defects | Number of Defects | penality points |
|---|---|---|---|
1 | Defects upto 3 inch | 8 | 8*1=8 |
2 | Defects above 3 inche & below 6 inch | 3 | 3*2=6 |
3 | Defects above 6 inche and below 9 inch | 2 | 2*3=6 |
4 | Defect above 9 inch | 2 | 2*4=8 |
Exercise:
Total penalty points=8+6+6+8=28 points
Calculation Formula of Total Points Per Yards for 4 point system?
the Formula is given below
Penalty Points x 36 x 100 / Inspected yards x measured cuttable width in inches
Penality points for the above excerise is
(28 x 36 x 100) / (140 x 56) =
the answer is 12.8 defect points per 100 square yards.
Now the lets discuss in below paragraph wether these penality points are in acceptable range or not.
Acceptable level for the 4 point system:
Knowing the acceptable number of points for a fabric roll’s length and width during inspection is crucial. Textile mills and buyers often have their acceptable point standards, but one can also refer to ASTM standards.
Rather than simply passing or failing rolls, textile mills, and buyers often use grading systems like first and second-grade quality.
It’s important to note that acceptable points can be defined in terms of points per 100 linear yards or points per 100 square yards. Acceptable points for individual rolls and the average points of all rolls can be set at different levels.
For example, any running defect exceeding 4 continuous yards will result in the rejection of the roll. Fabric widths up to 64-66 inches are considered first quality if the number of penalty points per 100 linear yards is not more than 50. For wider fabrics, the acceptable penalty points should be a proportion of 50 points per 100 linear yards, calculated using a 64-inch width.
In general, the acceptable levels of points per 100 square yards differ for different fabric types. For Cotton Twill/Denim, it’s 28 points per 100 square yards (23 points per 100 square meters), and for all synthetic fabrics, it’s 20 points per 100 square yards (16 points per 100 square meters), for individual fabric rolls.
The inspection format of 4 point system :
The most common fabric faults :
Neps: Small knots or grains in the fabric, usually caused by low-quality cotton.
Slubs: Thick areas in the yarn with tapered ends, larger than surrounding yarns.
Color Fly Yarns: Contamination or mixing of polypropylene (PP) during yarn making.
Coarse Yarn: Yarn larger than its neighboring yarns, often due to issues with the drafting mechanism in the spinning mill.
Broken Pick: Weft yarn breaks during weaving due to weak yarn strength.
Broken End: Warp yarn breaks during weaving due to weak yarn strength.
Cracks: Parallel warp or weft yarns shift, creating visible lines, often caused by yarn contraction or shrinkage.
Oil Stains: Stains on fabric due to mechanical issues or transportation.
Abrasion Marks: Marks on fabric due to tight temples on the loom or during transportation.
Holes: Fabric imperfections where one or more yarns are damaged enough to create an opening.
Selvedge Cuts: Weft cuts caused by poor weft yarn quality or improper loom adjustments.
Snags: Yarn pulled or plucked from the fabric surface.
Miss End or Warp Yarn: Missing yarn in the fabric.
Miss Pick or Weft: Missing weft yarn in the fabric.
These faults can affect the appearance, strength, and overall quality of the fabric.
Frequently asked Questions about 4 point system:
What is the 4 point system of fabric inspection?
The 4-point system is a method used to evaluate fabric defects based on four specified points: size, significance, and sometimes, type and location while Aql inspection system is used to evaluate the Finished products like towel,garments and hoem textile products.
How is the 4 point system used to grade fabric defects?
Fabric defects are graded based on their size and significance. Each defect is assigned a point value from 1 to 4, with 1 being the least severe and 4 being the most severe.
What are the four points in the 4 point system, and what do they represent?
The four points represent the severity of the defect: Point 1 is for minor defects that are barely noticeable, Point 2 is for defects that are noticeable but do not affect the garment’s appearance or performance, Point 3 is for defects that are noticeable and may affect the garment’s appearance or performance, and Point 4 is for defects that are severe and render the fabric unusable.
Can you explain how to calculate the total defect points in the 4 point system?
To calculate the total defect points, you add up the points assigned to each defect found in the fabric inspection. For example, if you find three defects with point values of 2, 3, and 4, the total defect points would be 2 + 3 + 4 = 9.
How does the 4 point system help in maintaining fabric quality standards?
The 4 point system provides a standardized method for evaluating fabric/terry towel defects, ensuring that all defects are assessed consistently. This helps in maintaining quality standards by identifying and addressing defects early in the production process.