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Four-Point System. Quality control System
Prepared By : Prepared By : Mazadul Hasan sheshir ID: 2010000400008 13thBatch (session 2009-2013) Department : Wet Processing Technology Email: mazadulhasan@yahoo.com Blog : www. Textilelab.blogspot.com (visit) Southeast University Department Of Textile Engineering I/A 251,252 Tejgaon Dhaka Bangladesh ©right
Introduction: Fabric quality control is accountable for assessing the good quality with the cloth and identifying whether or not the garments might be in a location to satisfy buyer requirements. Usually quality check workings are based and according to the approved sample by the customer. Quality check is done in order to meet the requirements of the customer in the fabric. Quality control workings start as soon as the fabric is in-house and cutting department issues an allocation to the quality control department. To ensure the fabric quality, circular machines as cut loop of cloth is cylindrical, the need for profile control sites. the same time, weaving fabric inspection, testing grams of quality, to ensure products meet design requirements.TCO has a whole system for verifying and maintaining a desired level of quality control of fabric quality inspection. We have a good system of fabric quality control: our QC members inspect bulk fabrics in all processes. Our inspection is usually 100%. Means that all the rolls of fabric required in making of the garment are checked. Someone will wonder how we can make it. The reason is that we try to narrow our profit margins in order to maximize our customer profit.
Quality control: "Quality" is defined as that combination of design and properties of materials of a product which are needed for the intended end use and level of the market in which it is sold. The systems required for programming and co- ordinating the efforts of the various groups in an organisation to maintain the requisite quality" As such Quality Control is seen as the agent of Quality Assurance or Total Quality Control.
Principle of quality control: The essential requirements for producing a reliable product has been stated as follows:- A satisfactory design of product, thoroughly proved by adequate development testing in order to establish its reliability under the conditions to which it will be subjected in use. This is the Requisite Quality of the product. A full specification of the requirements of this quality, which must be clearly understood by everyone concerned with the production of the constituent parts and of the complete end product. Confirmation that the manufacturing processes are capable of meeting these requirements. Full acceptance, by all those concerned with production, of the responsibility for meeting the standards set by the specification.
Principle of quality control: Checks on the product at every stage of manufacture to detect any departures from the specification. Record essential information derived from these checks to provide accurate evidence for action. Establishment of lines of communication, - i.e. Feedback to Production, - to ensure that this action is taken to effect the appropriate adjustments to materials, process and operatives to maintain FUTURE production within the specification. Instruction in the use, applications and limitations of the product. A study of user experience, feedback to the department's concerned, and rapid remedial action.
Piece Goods Inspection : Fabric Quality Control: If you want to produce high quality garments, you need high quality piece goods. When a sewing factory receives fabric from the mill, it is difficult to conduct a full 100% inspection of the fabric. Apparel Search recommends a minimum 10% inspection of all piece goods prior to spreading the fabric. Many factories attempt to inspect the fabric during the spreading, but this is probably unrealistic to depend on the spreader to control the fabric quality evaluation. The fabric should be inspected prior to the fabric reaching the cutting tables. There are several piece good inspection systems for measuring the quality of fabrics. Their is a
Piece Goods Inspection : Fabric Quality Control: Ten-Point System, which was developed in the 1950's. That system assigns penalty points to each defect, depending on the length of the defect. The system is a bit complicated because the points per length vary for warp and filling defects. There is also a Dallas System published in the 1970's. That system was developed specifically for knits. According to this system, if any defect was found on a finished garment the garment would then be termed a second. In regard to fabric, this system defines a second as "more then one defect per ten linear yards, calculated to the nearest ten yards." For example, one piece 60 yards long would be allowed to have six defects. Another system for evaluating piece goods is the Four-Point System. In this system, you should inspect at least 10 percent of the total rolls in the shipment. Make sure to select at least one roll or each color way. The defect classification works as follows.
Size of Defect: 3 inches or less = 1 point penalty Over 3 inches but not over 6 inches = 2 point penalty Over 6 inches but not over 9 inches = 3 point penalty Over 9 inches = 4 point penalty Note: a maximum of 4 points should be charged to one linear yard. Also, note that only "major" defects are charged. The acceptable score varies. Many companies use 40 points per 100 yards as acceptable defect rate. However, others may find this not acceptable...
Here is some math to show you an example. Total Yardage received: 5400 Acceptance Point-count: 40 per 100 yards Total Yards Inspected : 540 Total penalty points found in the sample inspection: 150 points 150 divided by 540 times 100 = allowance is 40 points per 100 yards, this shipment would be acceptable). 27.77 points per 100 yards (because the Above are only a few examples of fabric testing procedures. In fact, above is only a short summary of the processes. If you are responsible for inspecting fabric, you really will need to do more research on this subject
Processed Fabric Inspection Under 4 - point system All fabric inspections conducted by Textile Links and Controls is according to the four- point fabric inspection system. The four-point system derives its name from the basic grading rule that a maximum of four penalty points can be assessed for any single defect and that no linear meter can be assigned more than four points regardless of the number of defects within that piece.
PENALTY POINT EVALUATION: Defects in both warp / fill directions will be assigned points under the following criteria. Defect Range Points Evaluation Up to 3 inches 1 Point > 3 inches < 6 inches 2 Points > 6 inches < 9 inches 3 Points > 9 inches 4 Points
Acceptance Calculation Roll length in meter = A Total points found = B Acceptance Value = B/A x 100 points per 100 meter Acceptance range Range <40 points 41 – 60 points 61 – 80 points Above 80 points Grade A B C Reject If the fabric is found within acceptance limit then it is delivered to Garments section. But if the fabric fault is so high that cross the acceptance limit then it is rejected.
FAULTS RESPONSE 4 Points 4 Points 4 Points* 1 Points 2 Points 1 Points 2 Points 4 Points Stop/Starting mark Thick/Thin warp or weft yarn All holes regardless the size Slub : 0-3” of length Slub : 3”-6” of length Oil spots**:up to 5 mm dia Oil spots : 6 to 10 mm dia Oil spots : More than 10 mm dia Loose or tight warp Miss pick/Double pick Cut pick/Broken pick Yarn contamination : up to 0.5 of length Yarn contamination : above to 0.5 of length Neps Smash Knot Point will be consider according to fault size 4 Points Point will be consider according to fault size 1 Points 2 Points 1 Points 1 Points 1 Points Fabric with crease mark will be rejected but light crease may be acceptable. 1 Points 2 Points 4 Points 4 Points 4 Points Crease mark Dirty mark : up to 5 mm dia Dirty mark : up to 10 mm dia Dirty mark : above 5 mm dia Design fault Patta
WHAT IS A DEFECT? The length of the defect is used to determine the penalty points. Only major defects are considered. A major defect is any defect, if found on a finished product, would classify the product as a B- grade. Any defect of a continuous nature shall be assigned four points for each meter in which it occurs. Severe defects are assigned the maximum four points for each meter in which they occur. Example: Regardless of size, a hole would be penalized four points. Continuing conditions such as barre, side center side shading, roll to roll shading, narrow or irregular width, creasing, uneven finish shall be counted four points for every meter within the shipment that is found to contain these conditions, provided that the article that is to be made from this fabric is classified B-grade due to this fault. The maximum penalty for any one-meter shall not be more than four points. A minor defect is any defect that does not classify the product as B-grade because of either severity or location. When inspecting fabric before cutting, it is necessary to rate questionable defects as major, since the inspector will not know where the defect may occur on the item.
WHAT IS A DEFECT? RUNNING DEFECTS: Any major defect found to repeat and / or run in a continuous manner will constitute a running defect. All major running defects must be assigned four penalty points to every meter in the roll where it occurs. FULL WIDTH DEFECTS: A full width major defect would cause that meter of fabric to be assigned four penalty points. FABRIC WIDTH: Fabric width will be checked minimum of three times during the inspection of a roll (beginning,middle and end of the roll).Rolls having width less than the specified are potential problems. In such cases width deviation of more than 1% would constitute a major fault. Overall, fabric width is measured from out side of the selvage to the outside of the opposite selvage. ROLL LENGTH: Rolls having meters less than that stated on the packing are a problem. Any roll having more than 1% lesser fabric than that specified is rejected. The entire shipment shall be rejected if the total measured meters in the sample audit are more than 1% short that what is declared on the packing.
DEFECT SPLICES: Rolls can be composed of several spliced parts. No roll shall be accepted that contains a splice less than twenty five ( 25 ) meters in length unless otherwise expressly accepted. Ensure that the 95% of the shipment contains 100 meter plus fabric length if the fabric is being used for made - ups. In case of piece goods, the fabric length and the number of splices / roll are strictly followed as per the requirement of the customer. BOW & SKEW: No roll shall be accepted as first quality that exhibit bow or skew more than: Fabric Width Up to 45 inches 60 inches 90 inches and above Maximum Bow or Skew Design 2.0% 2.0% 2.0% Print/dyes Deviation 2.0% 2.0% 2.0%
DEFECT The above is subject to change if buyer requires a tighter tolerance / nature of design / end use of the fabric.Tolerance for bowed condition not affecting the full width will be fractionalized part of the maximums as stated above according to the area affected by the bow. Penalty points will not be assigned for fabrics found to have conditions of bowing in excess of the above stated tolerances but shall be noted in the inspection report. And if any fabric exhibits bow or skew where its end use becomes doubtful, then that fabric will be rejected. FABRIC ODORS: No roll shall be accepted that exhibits objectionable odors. HOLES: All defects that break the fabric, regardless of size, shall be penalized a maximum of four points. A hole consists of two or more broken yarns.
COMMON FABRIC FAULTS: Although fabric faults are numerous but some of the common fabric faults are mentioned below: Abrasion Mark: A place in the fabric where the surface has been damaged due to friction or abnormally weakened by any operation through which it has been passed. Bow: When the filling yarns lye in an arc across the width of the fabric. Skew: Distortion in the construction of the fabric i.e. in the yarn that constitute the fabric. Crease: A fabric defect across the fabric width usually caused by a sharp fold. Oil Stain: Oil mark on the fabric. Dye Stain: An area of discoloration due to un- even absorption of colorant. Hole: A break in the fabric involving more than two yarns.
COMMON FABRIC FAULTS: Mispick: A pick not properly interlaced. Double Pick: Two yarns running simultaneously, mostly in the weft. Misprint: In printed fabrics, either missed, or partially missed, or incorrectly positioned relative to each other. Slub: An abruptly thickened place in a yarn. Screen Out: The appearance of a colored separation line in a printed design. Calendar Line: Sharp pressmark on fabric due to the calendar during the processing. Contamination: Colored fibers with the warp or weft fibers.
POINT CALCULATIONS: The following fabric penalty point grading standards are to be used when inspecting fabrics. Individual Roll Points: All decisions are based on a square meter computation. The following is used to determine the point count for each roll. (Total points * 3937) / (Inspected meters * Fabric width (inches)) = Points per 100 square meter. Points: The total point count per contract fabric is calculated by: Adding the number of meters audited.Adding the number of points per linear meter.Then converting the above totals from points per linear meters to square meters. (Total linear meter points * 3937) / (Total inspected meters * Fabric width (inches)) = Shipment points per 100 square meter. The maximum approved points as per Textile Links & Controls for piece goods / made - ups fabric is 15 / 100 square meter. And for greige fabric it is 10 / 100 square meter. Or this could be followed as per the standards given by the customers.
INSPECTION QUANTITIES: A minimum 10% quantity of fabric for each color way, design, fabric width or fabric construction listed against a particular contract must be inspected. In case, if any problem arises in any of the above style then it has to be re-inspected another 10%. If the problem is still present and the points exceed the acceptable limit, the fabric lot is to be rejected.
ROLLS SELECTION PROCEDURE: The person inspecting the fabric must count the rolls of fabric against a particular contract & take out 10% of the fabric randomly in such a way that every color, design, fabric width & fabric construction is accounted for.
FABRIC INSPECTION PROCEDURE: This procedure shows the steps necessary to ensure an effective fabric inspection quality control program: 1. Determine the fabric quantity to be inspected. 2. Select the fabric rolls for inspection. 3. Place the fabric roll / bale on inspection frame / table. 4. Cut off a 6-inch piece across the width of the fabric from the beginning of the roll. Mark this piece so that the inspector will know the right and left side of the fabric. Use the strip to check the shading side-to-side and end-to-end by checking it at least against the middle of the 5. roll and once at the end of the roll. 6. Inspect for visual defects at a speed slow enough to find the defects. 7. Check that the roll contains the meters as stated by the Fabric Supplier. 8. Check for bowing & skewing in the fabric. 9. Major fabric defects are to be flagged by the Fabric Supplier. However, if any fault is not flagged already then it must be marked with a sticker or masking tape during inspection for its trace- ability and corrective action at cutting stage. 10. Record the faults of the fabric on the Fabric Quality Report.
ROLL-TO-ROLL SHADE CHECKING SYSTEM: Textile Links and Controls suggests to use a format for the checking of all fabric shade variations from roll to roll. In this format water falls of different shades’ categories of different rolls is maintained and compared to each other to check the extent of the shading variation. If any shade requires special attention / treatment in the cutting, it is mentioned in the remarks column. If any fabric is out of tolerance with respect to the Master Sample or the shade variation extent among the rolls is out of tolerance, then the fabric is reject. The rejected fabric is sent back to Fabric Supplier for reprocessing / replacement.
TOOLS FOR FABRIC CHECKING: The person who is responsible for fabric inspection must have the following facilities / equipments in good working condition. 1. Inspection frame with counter. 2. D - 65 light source (sunlight) / TL - 84 light source at the inspection frame as per the requirement of the customer. 3. Measuring tape & pair of scissors. 4. Stickers or masking tape to identify the faults. 5. Pick glass. 6. Digital Camera for taking reference snaps. 7. Master fabric sample or customer’s reference sample. 8. Textile Links and Controls fabric inspection form.
ELIGIBILITY CRITERA FOR THE QUALITY INSPECTOR: 1. The person must be at least Graduate. 2. He or she must have a minimum of two year experience in the textile industry. 3. He or she must be well versed with the 4-point fabric inspection system. 4. He or she must be active and physically fit. 5. He or she must not be colorblind.
General Inspection Procedures Fabric inspection is done in suitable and safe environment with enough ventilation and proper lighting. 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. Fabric speed on inspection machine must not be more than 15 yards per minute. All fabric inspection must be done when 80% of good or lot is received. Standard approved bulk dye lot standards for all approved lots must be available prior to inspection. Approved standard of bulk dye lot must be available before starting inspection for assessing colour, hand, weight, construction, finish and visual appearance. 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. Textiles like knits must be evaluated for weight against standard approved weight. Fabric width must be checked from selvage to selvage against standard. All defects must be flagged during inspection 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. If yard dyed or printed fabrics are being inspected the repeat measurement must be done from beginning, middle and end of selected rolls.
Four Point System of Textile Inspection Four Point System is based on penalty points given to a defect found when inspecting fabric. Rule is as below: Not more than four penalty points may be given for any single defect. No more than four penalty points may be given to one linear yard/meter regardless of the number of defects found within one yard/meter. For continuous defects such as shading between side, centre side, side to side shading, end to end shading no penalty points are assigned but the roll is graded as second quality and must be reported to mill for replacement.
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