Inspection

Fabric inspection systems -types of fabric defects (woven and

knits) -Grading of fabrics and its usage

Inspection

• Inspection in reference to the apparel industry can be defined as the visual examination or review of raw materials (such as fabric, buttons, zippers, sewing threads, trims etc,), partially finished components of the garments and completely finished garments in relation to some standards, specifications, or requirements, as well as measuring the garments to check if they meet the required measurements.

Principle of Inspection• The principle involved in inspection is the early

detection of defects, feedback of this information to the appropriate people, and determination of the cause, ultimately resulting in the correction of the problem.

• The main objective of inspection is the detection of the defects and nonconformance’s as early as possible in the manufacturing process so that time and money are not wasted later on in either correcting the defect or writing off defective garments.

Inspection Loop

• For inspection to be effective, the entire inspection loop is shown below must be completed

The inspection is divided into the following three sections

• 1). Raw Material Inspection.• 2). In-process Inspection.• 3). Final Inspection.

Raw Material Inspection – Fabric Inspection

• After fabric is received, it should be inspected to determine its acceptability from a quality viewpoint; otherwise extra cost in garment manufacturing may be incurred due to either the loss of the material or time, to say nothing of customers returns and dissatisfaction due to poor quality.

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• Some garment manufacturers rely on the fabric suppliers to perform the fabric inspection and mark fabric defects.

• Either way the fabric is inspected prior to spreading will remove the burden of the quality responsibility from those performing the spreading and cutting operations.

• A spreader will be able to concentrate on spreading more quickly without having to worry about inspecting the fabric.

• A cutter’s productivity would increase because the defects are already marked. In many small companies spreading and cutting is done by the same personnel and fabric is inspected as it is being spread on a table for cutting.

• Regardless of what practice is followed, the important point is that the fabric should be inspected before cutting, the defects marked and the patterns cut around the defects so as not to include them in the finished garment.

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Fabric Inspection Machine

• Fabric inspection is usually done on fabric inspection machines.

• These machines are designed so that rolls of the fabric can be mounted behind the inspection table under adequate light and rerolled as they leave the table.

• Defects in the fabric can be seen easily and readily with these machines, as the inspector has a very good view of the fabric and the fabric does not need to be reversed to detect defects.

• The inspection machines are either power driven or the inspector pulls the fabric over the inspection table.

• The defects are located, marked and recorded in the inspection form. Such machines are also equipped to accurately measure the length of each roll of the fabric as well as monitor the width of the fabric.

• The width of the fabric is very critical to the cost of the manufacturing but it may be even more critical to the manufacturers of basic garments such as men’s and boy’s underwear who frequently reuse the markers, make pattern changes less often, and perhaps use tight markers resulting in greater fabric utilization.

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• Therefore the Variation in the width would result in the higher cost of manufacturing for such companies. On the other hand, fashion garment manufacturers frequently change their patterns and therefore do not use the same markers again and again, so variation in fabric width may not be as much of a problem for them as for the manufacturers of basic garments.

• Also the profit margin for the basic garment manufacturers is usually lower than the fashion garment manufacturers, and therefore, maximum fabric utilization is vital for basic garment manufacturing companies.

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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.

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• 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.

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• In India and many other countries fabric inspection many times is carried out manually, either on a slanting inspection table or on a horizontal table, some time with light under it or some time without it. T

• his way of fabric inspection is neither effective nor efficient.

Fabric inspection systems• There are various fabric inspection systems, as

listed below. However, the 4-point system and 10-point system are used most widely.

– 4 – Point System– 10 – Point System– Graniteville “78” system– Dallas System.– Textile Distribution Institute (National Federation of

Textiles-1955) System– 4 – Point System revised.

4 – Point System

• The 4 – Point System, also called the American Apparel Manufacturers’ Association (AAMA) point grading system for determining fabric quality, is widely used by producers of apparel fabrics and by the department of Defense in United States and is endorsed by the AAMA as well as the American Society for Quality Control (ASQC).

Fabric flaws or defects are assigned point values based on the following

Length of the defect in fabric, either warp or weft wise direction Points allotted

Up to 3 inches 1Over 3 inches up to 6 Inches 2Over 6 inches up to 9 inches 3Over 9 inches 4Holes and openings (Large Dimensions) 1 inch or less 2Over 1 Inch 4

• The total defect points per 100 square yard are calculated, and normally those fabric rolls containing more than 40 points per 100 square yard are considered as “seconds”.

• However, a garment may use more or less than 40 points per 100 square yards as an acceptance criteria

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• Therefore Points per 100 Square yards =Total points scored in the roll X 3600_______Fabric width in inches X total yards inspected.

The following points are worthy of note:

The maximum number of defect points to be counted against any one linear yard is 4 points. Overall, fabric quality is assessed on the basis of the number of defect points per 100 square yards of fabric.

The fabric is graded regardless of the end product. However, this drawback can be overcome. For example, a manufacturer may decide to use different point values for first and second quality fabrics (or acceptable / rejection criteria) depending on the end item being manufactured. For example, acceptance / rejection criteria of 40 points / square yard may be alright for fabric for men’s casual trousers and sports shirts, but the same may not be adequate for fabric for men’s suits. Different types of fabrics have different point levels of acceptability. These levels of acceptability are usually established by the mutual agreement between the buyer and the seller.

• A defect point in a 4 – Point system is not a consistent unit of measure.

• For example, 4 points when representing slubs may affect no more than 4 inches of defect, but when representing a full width of defect in a 60-inch wide fabric, 4 points represent 60 inches of continuous defect.

• In the first case, a point represents 1 inch or less, whereas in the second case, a point represents 15 inches of defect. This system is not sensitive to the width of the fabric being inspected.

• The 4 – point system makes no provision for the probability of minor defects causing seconds or minor defects falling out on the cutting table, being lost in the fabrication or escaping scoring in the finished garment.

• There are defects accepted inconspicuous areas of the first quality garments and rejected when found in conspicuous areas. There is no provision for the very influential factor

• There is no standard sampling plans used in the industry for the inspection of the fabric or piece goods.

• No industry standards or acceptable limits exist for shortage in number of yards on roll of fabric

Defects which must be scored includes the following• Bar – Filling wise thick place, thin place, coarse

yarn or fine yarn.• Bad Selvedge – Loose, tight, beaded, raged etc.• Broken End – A warp yarn missing for a portion of

its length• Chafe – An area where the fabric has been

damaged by abrasion or friction.• Coarse End Or Pick – A warp or weft yarn having

larger diameter or more plies than normally used in the fabric.

• End Out – A warp end missing from the entire length of the cloth.

• Fine End – A warp yarn having smaller diameter or less plies than normally used in the fabric.

• Flat – Two or more threads weaved as one and not meant to be a feature of the weave.

• Float – A thread that extend unwoven over the threads of the opposite set with which it should normally be interlaced.

• Fly – loose fibers not originating from the fabric or foreign mater that have been woven into the fabric.

• Fuzz Balls – Loose fibers originated from within the fabric that have formed balls and is woven into the fabric.

• Hard Size – An excessive quantity of size material. • Double Pick – An extra pick dragged into shed

with the correct pick for a portion of the width of the fabric

• Kink (Snarl) – A short length of yarn spontaneously doubled on itself.

• Misspick – A pick woven in the wrong order with respect to the weave or colour pattern.

• Missing End – A warp wise streak causing the improper spacing of the warp across the fabric.

• Mixed Yarn – Yarn that differs from that used in normal.

• Reed Mark -- A warp wise streak caused by damage reed.

• Smash – An area where the fabric been ruptured by breakage of large number of ends.

• Temple Mark – Disturbance of the appearance at the temple region.

• Tight end or pick • Torn Selvedge