4-points fabric inspection method in garments sector

Fabric inspection system is the very important part in the garments & textile sector. The 4-Point System also called the American Apparel Manufacturers (AAMA) point-grading system for fabric quality & widely used by producers. Generally, 4-Point System is an agreed upon system by the customer & inspection is carried out on a fabric inspection machine.4-points inspection method identify different types of fabric fault. After read this article we can easily understand the 4-points inspection system.

General Inspection Rules:

1. Fabric inspection is done in suitable and safe environment with enough ventilation and proper lighting.
2 Fabric passing through the frame must be between 45-60 degree angles to inspector and must be done on appropriate Cool White light 2 F96 fluorescent bulbs above viewing area. Back light can be used as and when needed.
3. Fabric speed on inspection machine must not be more than 15 yards per minute.
4. Standard approved bulk dye lot standards for all approved lots must be available prior to inspection (if possible)
5. Approved standard of bulk dye lot must be available before starting inspection for assessing color, construction, finish and visual appearance.
6. Shade continuity within a roll by checking shade variation between centre and selvage and the beginning, middle and end of each roll must be evaluated and documented.
7. Textiles like knits must be evaluated for weight against standard approved weight.
8. Fabric width must be checked from selvage to selvage against standard.
9. All defects must be flagged during inspection.
10. The length of each roll inspected must be compared to length as mentioned on supplier ticketed tag and any deviation must be documented and reported to mill for additional replacement to avoid shortage.
11. If yarn dyed or printed fabrics are being inspected the repeat measurement must be done from beginning, middle and end of selected rolls.

A major defect is any defect that, if found in a finished fabric /garment, would classify that fabric / garment as a second- rated.

 Major woven fabric defects are
• slubs, hole, missing yarn, conspicuous yarn variation, end out, soiled yarn, wrong yarn.
Major knitted fabric defects are
• mixed yarn, yarn variation, runner, needle line, barre, slub, hole, and press off.
  Major dye or printing defects are
• Out of register, dye spots, machine stop, color out, color smear, or shading.
• The Quality Inspector may include any other defect which he feels are of a major category and may forward such defect details to the customer for feed back as and when required.

Defects Rules:

1. A continuous of defect shall be assigned four points for each linear meter or yard in which it occurs.
2. Any piece having a running defect through more than three continuous linear meters or yards shall be rejected. Regardless of point count.
3. Any piece with a full width defect over six inches in length shall be rejected.
4. Any piece that contains more than three full width defects per one hundred linear meters or yards shall rejected.
5. No piece shall be accepted that contains a full width defect in the first and last three meters or yards.
6. A hole or torn is considered to be a major defect and shall be penalized four points.
7. Fabric construction and weight, No tolerance will be allowed.
8. The distance between major defects should be more than 20 meters.
9. All major and full width defects should be seemed a polyester thread at the selvedge.
10. Waviness, tightness, ripples, puckering in body of fabric which would prevent the fabric from lying flat when spread in a conventional manner is not acceptable.

Defect Classification using 4-Point System:

The 4-Point System assigns 1, 2, 3 and 4 penalty points according to the size and significance of the defect. No more than 4 penalty points can be assigned for any single defect. Defect can be in either length or width direction, the system remains the same. Only major defects are considered. No penalty points are assigned to minor defects.

Firstly, we inspect 10 % of the total quantity. if any fail 10% then again 10% will cheek. If total fabric yds 2000 yds & per roll fabric 50 yds then total roll will be 40 roll.So,10% of the 40 rolls will be inspect 4 rolls. The maximum number of defects per 100 yards.

Example:

8 defects up to 3″ length———8 x 1 =8 points
6 defects from 3″ to 6″ length—-6 X 2=12 points
2 defects from 6″ to 9″ length—-2 X 3 =6 points
1 defect over 9″ length———-1 X 4 =4 points

Total defect points ——————–30 Points

So,we can use formula

Points per 100Sq yards=Total points for the roll X3600/ Total roll length in yards X Cuttable width in inch.
Points / sq. yards = (30 X 3600) / (150 X 56)
= 12.857 points

In this conclusion we can say that 12.857 point should we accept or reject the inspection. It depend on customer or companies. Normally, within 100yds we can get defects less than 40 points that it can accept & if above 40 points then it will second goods or rejected.

Md.Mahbub-Ul Islam

RMG Consultant & Researcher

mahbub.islam54@gmail.com