Fabric Inspection Systems:
Fabric inspection is an essential process for maintaining the quality of a fabric. The word ‘inspection’ in the garment industries relate to the visual examination or review of raw materials (such as fabric, accessories, trims, etc.). After the receipt of a fabric roll to the garment industry, it must be inspected to evaluate its tolerability from quality point of view or else additional cost in garment manufacturing may be incurred. It is normally carried out on fabric inspection machines, which are designed such that fabric rolls are mounted at the back side of the inspection table. As the fabric is moving at a slow speed and at an angle, the fabric inspector has a better view of the fabric and could identify faults easily. These machines are normally power driven or the operator has to pull the fabric over the inspection table. The fabric faults are identified, labelled and recorded in a fabric inspection form.
Types of Fabric Inspection Systems in Apparel Industry:
The various fabric inspection systems used in the garment industry are given here.
- Four-point system
- Ten-point system
- Graniteville “78” system
- Dallas system
- Textile Distributors Institute system (National Federation of Textile 1995)
4 points fabric inspection system:
Of the above methods, the four-point system is widely used in the garment industry. It is a commonly established method of fabric inspection globally. Fabric inspection is done as per ASTM D 5430–04 standard and this system is agreed by The American Society for Quality Control, Textile and Needle Trades Division, The American Apparel Manufacturers Association and is used by the United States Government for all of their piece goods purchased.
Fabrics are usually graded using the ‘four-point system’ where all defects that are clearly noticeable from 3 feet are scored as a defect and demerit points are assigned according to the severity. Certain specialty fabrics, styles, colors and products from new suppliers undergo examination up to 100% of delivered goods.
The main considerations in a four-point inspection system are given here:
- The fabric has to be passed longitudinally through the inspection area at a speed approved by the customer.
- The light source should be perpendicular to the fabric surface and the fabric should run at an angle of 45° to the vertical for better vision for the operator.
- The illumination intensity in the inspection room should have a minimum of 1075 lux and the light source used should be white fluorescent lamps.
- The fabric should be checked at a distance of 1 m from the fabric inspector when it is in motion.
- Defect points should be assigned based on the length of the defect as mentioned in Table -1.
- Four points should be assigned to each meter of fabric where usable width is lower than the minimum specified.
- The fabric should not be penalized more than four points.
- Defects not obvious on the face side of the fabric should not be registered unless agreed between supplier and customer.
Table-1: Assignment of Penalty Points in Four-Point System
Total defect points per 100 square yards of fabric should be determined and the criterion for the acceptance of a fabric roll is generally not more than 40 penalty points. If it is more than 40 points, it will be considered ‘seconds’.
The formula to determine the penalty points per 100 square yards is given by-
……….Total points scored in the roll x 3600
= ———————————————————————————–
…Fabric width in inches x Total yards inspected
Example:
A fabric roll 160 yards long and 47″ wide contains the following defects as shown in Table-2.
Table-2: Example of defective points in fabric
| 4 defects up to 3″ length | 5 × 1 | 5 points |
| 3 defects from 3 to 6″ length | 2 × 2 | 4 points |
| 2 defects from 6 to 9″ length | 4 × 3 | 12 points |
| 1 defect over 9″ length | 2 × 4 | 8 points |
| 1 hole over 1″ | 1 × 4 | 4 points |
| Total defect points | 33 points |
Therefore, points/100 sq. yards = (33 × 3600)/(160 × 47) = 15.79 points
Advantages of 4 point system:
- Four-point system has no width limitation.
- Worker can easily understand it.
10 point system in fabric inspection:
10 point system separates defects by the warp and weft directions, which adds another layer of fabric grading. This system is challenging in everyday use. Penalty points are determined by the number of defects and length of each defect. The ten-point inspection system for fabric evaluation was permitted by the Textile Distributors Institute and the National Federation of Textile in 1955. It is designed to categorize the defects and to assign each defect a numerical value based on severity of defect. The system allots penalty points to each defect based on its length and whether it is in the warp or weft direction. Table-3 shows the assignment of penalty points in a ten-point system.
Table-3: Assignment of Penalty Points in Ten Points System
| Warp Defects | Points | Weft Defects | Points |
| Under 1″ | 1 | Under 1″ | 1 |
| 1–5″ | 3 | 1–5″ | 3 |
| 5–10″ | 5 | 5″–1/2 width of goods | 5 |
| 10–36″ | 10 | Over 1/2 the width of goods | 10 |
According to this system, the fabric roll is considered good if the total penalty points, assessed to that roll, do not exceed the length of the fabric. If the points exceed the length of fabric in a roll, then it is considered ‘seconds’ and may be rejected. Suppose if the fabric roll having a length of 50 yards is inspected in a ten-point system and the total penalty points are less than 50. Then the fabric roll was considered good.
Advantages of 10 point system:
- Oldest and most used in woven finished fabric.
- In it length of fabric is used and along the length of warp and weft defects are identified.
Disadvantages of 10 point system:
- It has width limitation.
- It is difficult in practical use.
Graniteville “78” System:
It was introduced in 1975 for the field of fabric grading. In this system, fabric defects are sorted into major and minor categories. If fabric has numerous major defects, then the fabric might be considered second-quality fabric and sold for less or encouraged to be reworked and sold as first quality. With this fabric-grading system, small and minor defects are often overlooked and not counted in the total penalty points (see Table-4). This system is recommended for garments and other textile products with large pattern pieces on wider widths of fabric.
This system was basically established for garment cutting components, in which the short length faults less than 9″ would normally be removed. The system aims to balance the significance of longer defects (over 9″) and place less weight on 1–10″ faults such as slubs. The system recommends the viewing distance of 9′ instead of the normal 3′ distance.
Table-4: Assignment of Points in Graniteville “78” System
| Defect Length | Penalty Points |
| 9″ | 1 |
| 9–18″ | 2 |
| 18–27″ | 3 |
| 27–36″ | 4 |
Disadvantages of graniteville 78 system:
- As this system is used on cutting pieces, according to my point of view it also increases the cost of production. We should control problems before cutting.
Dallas system fabric inspection:
The Dallas system was introduced in the 1970s and it was developed particularly for knitted fabrics. According to this inspection method, if any fault was observed on a finished garment, then the garment would be called ‘seconds’. It describes the seconds as ‘more than one defect per ten linear yards, determined to the nearest ten yards’. For example, one piece 60 yards long would be allowed to have six defects. This is not widely used.
Disadvantage of Dallas system:
- It increases the cost of production as defect is located after the garment is finished.
References:
- Apparel Manufacturing Technology by T. Karthik, P. Ganesan, and D. Gopalakrishnan
- Garment Manufacturing Technology by Rajkishore Nayak and Rajiv Padhye
- Garments and Technology by Professor M. A. Kasem.
