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    About us

    Ludhiana City

    Ludhiana Knits




    Code Of








    Industry Infrastructure

    Knitted Fabric Quality & Controls

    Fabric quality

    Stitch density

    Stitch length

    How to find loop length?

    Course length

    Fabric cover

    Fabric weight per unit area

    Fabric width

    Fabric Shrinkage

    Knitted faults

    Yarn Faults



    Knitted fabric standards

    Four-Point System

    Knitted Garment Quality

    Yarn quality assessment
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    Fabric quality assessment

    In-process quality control

    Quality control during spreading

    Quality control during cutting

    Quality control during sewing

    Final Inspection

    Dimensional & design Considerations


    Design Factors

    Fabric quality

    Before we understand fabric quality let us first know what are

    the properties of knitted fabrics. The commonly used

    terminology connected with the properties of the knitted

    fabric is as follows. (These expressions are mostly used for

    circular knitted fabrics)

    1. Stitch density, or loop density

    2. Stitch length, or loop length

    3. Course length

    4. Fabric cover

    5. Fabric weight per unit square

    6. Fabric width

    7. Fabric shrinkage

    Stitch density

    The most important property of knitted fabric is its stitch

    density or loop density, i.e., the number of loops (stitches)

    per square inch or centimeter of the fabric (loops per square

    inch or loops per square centimeter etc).

    The loop density is directly related to;
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    Fabric appearance,

    Fabric weight per unit area,

    Fabric thickness,

    Fabric drape and many other factors.

    Loop density in turn would depend upon the length of yarn,which makes one loop (stitch).

    1.1.2 Stitch length

    The length of the yarn in one loop is known as stitch length.

    In the fabric shown in the figure above, there are 17 stitches

    wale wise (width wise) and 14 stitches course wise (length

    wise). Therefore, the loop density of the fabric is 17 x14 = 238

    stitches per square inch.

    In general terms, for any knitted fabric, as the stitch length

    increases the loop density decreases, and higher stitch

    lengths will make the fabric porous. So we can say that the

    loop density is directly related to the loop length. For simple

    fabrics the relationship between loop density and loop length

    can be expressed as an equation given below:

    S = K/L 2

    Where S is the loop density, L is the loop length in

    centimeters and K is a constant for the particular

    construction. After a large amount of data and research

    definite values of K have been proposed. These values range

    19 to 21.6 depending upon the dry or relaxed state of the


    Stitch density is also expressed as follows;

    Stitch density = wpi x cpi

    Where, wpi stands for wales per inch and cpi stands for

    courses per inch.

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    The above formula is true only for plain knitted fabrics. For

    complex structures the formula is not true.

    How to find loop length?

    From a given plain knitted fabrics, the loop length can be

    found out by unraveling yarn from known number of loops of

    the fabric and measuring its length in centimeters using a

    crimp tester (or straightening the yarn by hanging a small


    Length of the yarn unraveled divided by number of loops

    unraveled will give the loop length.

    To arrive at accurate loop length the mean of several lengths

    unraveled is divided by the number of loops in the course

    unraveled. It is usual to use 100 loops in this measurement.

    The second precaution is that the yarn unraveled must be

    straightened properly to remove the crimps in the yarn. Also

    the yarn should not be over stretched while straightening.

    Preferably a crimp tester should be used, if available.

    Course length

    A circular knitted fabric is composed of a number of courses

    that spiral around the fabric. Yarns fed by number of feeders

    positioned around the machine form these courses. Each

    feeder can be regarded as a separate knitting entity

    responsible for making a course in one circular rotation of the

    machine. The yarn length fed by one feeder that has been

    knitted in one complete rotation of the course is the course

    length and the number of loops, which this yarn has created,

    in one rotation are equal to the number of needles per

    centimeters of the knitting machine.

    If the feeding tension on each feeder differs, each feeder will

    produce a different course length. In feeders having more

    tension, tight course will be produced and where the feed

    tension is less a loose course will be produced. It is the aim of

    fabric quality control to make each course length as near as

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    possible to the specified value (to be determined depending

    upon the quality of the fabric to be knitted). When some

    courses are wildly out of specification and differ from one

    another, the fabric has horizontal bars that degrade its

    appearance and lower its perceived quality.

    Most modern circular machines producing simple fabrics are

    fitted with positive feed units that ensure much closer

    tolerances between feeders in respect of course length. For

    machines that do not possess positive feed or for fabrics that

    cannot be knitted under positive feed conditions it is difficult

    to produce good quality fabric.

    The tension of feeders is leveled using a combination of yarn

    speed meters and tension meters. During these quality

    control procedures it is essential that at lease one

    measurement be made on each feeder. Modern knitting

    machines can have in excess of 100 feeders, so the work can

    be extensive.

    Incoming fabric to the cutting room store would be

    examined for bars due to course length variations,

    and measure for loop density. Weight per square

    meter would also be taken, to alert Quality Control to

    possible aberrations.

    With circular machines the relationship of a particular feeder

    to the course it produces in the fabric is simple and


    With flat machines the situation can be more complex. With

    knitting taking place from left to right and then right to left, a

    different set of cams on the machine produce the knitting left

    to right, than produce it right to left. On simple flat machines

    with one cam box, alternate course will be knitted in right or

    left direction. In this case if feed tension differs in each

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    direction the course length variations is expected to alternate.

    On more complex knitting machines with two or more knitting

    systems (cams) traversing, the situation is more complex. On

    a two system V-bed flat machine there are four different

    groups of cams producing knitted courses A, B, C, D. if thecam carriage is moving from right to left, the two trailing

    systems B, D are knitting, with B knitting the first course

    followed by D. When the carriage is moving from left to right

    A and C are knitting, with C knitting before A.

    It is essential to know this aspect of knitting in order to set up

    the machine or locating a faulty course length distortion.

    Fabric cover

    Fabric cover is a simple ratio of the area of knitted fabric

    covered by yarn to the area covered by the gaps in between

    loops. Obviously, the cover of the fabric would depend upon

    two things;

    1. Loop density2. Yarn diameter (or count)

    A fabric knitted with higher loop density will have higher

    cover; similarly, a yarn with higher diameter will knit a fabric

    with higher cover. A fabric with higher cover is usually tightly

    knit and that with a lower cover is loosely knit. A normal fabric

    is one that is neither too tight nor too loose or floppy.

    So, the cover factor of a knitted fabric is related with yarn

    diameter (or count) and loop density or stitch length. There is

    simple formula that can be used to express cover factor or

    tightness factor.


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    Cover factor (cf) = Count in tex/L

    Where L is the loop length in centimeters.

    Usually in knitted fabrics, for fabrics of a similar construction,

    in order to maintain same cover, a higher loop length would

    require higher size of yarn (coarser count).

    Fabric weight per unit area

    Weight per unit area of fabric is an important property that is

    again related to another properties of the fabric, i.e., loop

    density and yarn size. Thus the weight of the fabric isdetermined by two factors that interact: the loop size and the

    yarn size. The effect of the loop size is simple to express: if

    the size of the yarn remains constant, then increase a loop

    size produces a fabric with lower loop density and produces a

    decrease of weight per unit area.

    So by doubling the loop size, the yarn per square area of the

    fabric becomes half, and so the weight per unit area will also

    become half.

    The calculations for weight/m2 is as under

    Specifications for knitted fabrics usually include quantities for

    loop density, width of the fabric and weight per m. The

    weight of the knitted fabrics is referred to as grams per

    square meters (GSM). Construction details of some of the

    important circular knitted fabrics are given below.



    Type of






    No of





    Min :



    1 Single Jersey 24 30" 2256 20s/1 135 170

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    2 Single Jersey 28 30" 2640 30s/1 110 145

    3 Single Jersey 28 30" 2640 40s/1 85 110

    4 Inter Lock 24 30" 4512 30s/1 215 270

    5 Inter Lock 24 30" 4512 32s/1 195 210

    6 Inter Lock 24 30" 4512 36s/1 180 195

    7 Inter Lock 24 30" 4512 40s/1 155 190

    8 Rib (1x 1) 18 30" 3360 30s/1 155 165

    9 Rib (1x 1) 18 30" 3360 40s/1 110 125

    10 Rib (2 x 2) 18 30" 2240 30s/1 155 165

    11 Rib (2 x 2) 18 30" 2240 40s/1 115 130

    Fabric width

    Fabric width of knitted fabrics is an important property. In

    order to avoid fabric wastage, the garment patterns should fit

    in the fabric width in such a way so that very little wastage is

    produced while cutting pieces. But if the fabric width is

    different than specified, it may produce high wastage.

    The fabric width of tubular fabrics or flat knitted fabrics may

    become different (usually lesser) than on the machine.

    Knitted fabric may change dimensions with time, handling

    and with subsequent wet treatments including steaming, and

    such changes can even occur after the garment has been

    produced and sold to the public. This phenomenon occurs

    due to relaxation of the fabric from the knitting tensions.

    Some fabrics come in the pre-shrunk condition, if a bettertechnology for finishing the fabrics has been used; however,

    there will still be some shrinkage due to relaxation.

    The concept of the relaxed state for knitted fabrics is well

    recognized and determined. Quality control must ensure that

    before knitted garments are cut, the fabric is in a relaxed or

    near relaxed condition, i.e., that there will be little shrinkage

    of fabric/garment when it is in the consumers possession.

    Relaxation tests can be carried out on fabric as a routine

    procedure, or as spot checks. Most test procedures involve

    agitation of a square cut piece of fabric in water solution

    followed spinning and tumble-drying. The change in the

    dimensions before and after wash treatment will tell us about

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    the extent of shrinkage which the garment may suffer under

    actual wash condition during usage. This test will also tell us

    the changes in the length and width the fabric will undergo

    while washing. This much allowance in the dimensions of the

    garment should be kept in mind while cutting the pieces.

    Fabric Shrinkage

    There are two types of shrinkages present in knitted fabrics;

    (1) Relaxation shrinkage

    (2) Washing shrinkage

    We have talked about these shrinkages above under the headof fabric width. Relaxation shrinkage occurs with the passage

    of time. The fabric becomes relaxed free from knitting

    tensions and so shrinks.

    Washing shrinkage occurs due to two factors, 1) due to

    release of any residual tension in the yarns with which the

    fabric is made of and the fabric itself, 2) due to inherent nature

    of the fibres of the fabric.

    Wool knitted fabrics with shrink-resist treatment pose little

    problem of shrinkage and deformation. Steaming of knitted

    garments blanks or garments on an open steam bed release

    the majority of stress in wool fabrics.

    Acrylic fabrics made from bulked yarns present few problems

    in dimensional stability. Steaming of knitted garments blanks

    or garments on an open steam bed release the majority of

    stress in wool fabrics.

    But, cotton knitted fabrics presents the greatest problems in

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    fabric shrinkage or deformation on account of both of the

    factors mentioned above. These fabrics may shrink up to 20%

    or more. Therefore, cotton knitted fabrics should be

    preshrunk and compacted before cutting and garment

    making. In view of this the technology for finishing cotton

    knitted fabrics is more elaborate, sophisticated and costly.

    The finishing technology of cotton fabrics include following

    steps and machinery;

    1. Dyeing and bleaching in soft-flow dyeing machines: These

    machines generate less of the tension on the fabrics.

    2. Hydro-extraction: This is done on a continuous hydro-extracting

    machine, which also spreads the width of the fabric while water is

    being extracted from the fabric.

    3. Relax dryer: These machines dry the fabrics in a fully relaxed

    state, so the fabric assume its relaxed width.

    4. Compacting calendar: This machine compact the fabric

    mechanically and calendars (press) to impart a good finish to the

    cotton fabrics.

    Fabrics treated with this technology has very less shrinkage,

    but still at least 2% to 5% potential shrinkage is still left, which

    is difficult to remove.

    A knitwear designer should know all terms and phenomenon

    of knitted fabrics so that a proper fabric may be designed for

    making garments. It is not the duty of the knitwear designer to

    set the machines or to select the treatment, which the knitting

    masters should do, however, it is essential that the designers

    should guide the knitting masters as to what sort of fabric is

    required by them.

    Knitted faults

    Some faults appear in the knitted fabrics and garments. These

    faults may be due to knitting itself or due to the yarns used.

    These faults have been tabulated below.

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    Spun-in Coloured Fibres

    Foreign Matters

    Long Thick Places



    Hole Spun-in


    FibresStains/Contamination Foreign


    Fly Short Thick


    Missed Stitch Long Thick


    Tear off Thin Ring

    Double stitch Long Thin


    Needle break Thick ring

    Transfer Stitch Short thin


    Rings (mixed yarns) Knot/Splice

    Dropped Stitch UnevennessLoop distortions Periodic


    These faults, if appear in the garments will downgrade the

    garment value.

    The knitted fabric or garment portions at the start of garment

    making process may exhibit the following observable faults;

    1. Variable loop length/course construction, showing horizontal


    2. Horizontal barring from a number of yarn characteristics;

    3. Vertical faults that are machine determined;

    4. Stains due to oiling or lint contaminating fabric

    Other than above a knitted fabric may have wrong

    specifications of the fabric.

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    The wrong construction, with loop length, width and

    weight per square meter variations from the


    All these observable faults are the subject of inspection

    procedures at the start of the garment construction process.

    Some faults are not necessarily observable at the start. Such

    faults relate to fabric shrinkage after being made into

    garments. The potential for shrinkage can only be detected by


    Some of these faults are discussed below.

    Yarn Faults

    Two types of faults are seen in the knitted fabrics.

    Horizontal faults

    Vertical faults

    Most faults that result in horizontal bars (thick sections

    distinguishable from the body of the fabric) are mainly due to

    yarn used. These faults occur due to;

    Difference in the counts of the yarn used: Supposing in a cone

    few meter of the yarn is thicker or thinner than the remaining yarn.

    The thick or thin portion when knitted along with normal yarn

    sections will show as a horizontal bar.

    Different dyeing shades in yarns used: Supposing in a cone few

    meter of the dyed yarn has different yarn shade than the

    remaining yarn. The dark or lighter portion of yarns when knitted

    along with normal shade of the yarn sections will show as a

    horizontal bar.

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    Different spinning batch/source of yarns: A fabric produced from

    cones having yarns of different batches produced in the spinning

    mills, when dyed may show horizontal bars. Since different

    batches of yarn may differ in cotton type and mixing and pick-up

    different dye content during dyeing process.

    Different bulking heat treatment given to acrylic yarns: The

    bulking treatment (steam heating in a chamber) given to high bulk

    acrylic yarns (2/32s acrylic yarn types) may pick-up different heat

    due non-uniform steam spread in the chamber. The yarns with

    lesser bulking may pick-up different dye contents and when

    knitted may show-up as bars.

    All these faults characterize themselves as bars across the

    fabric, of density, colour or luster, and must be detected in the

    fabric before is cut into the garment, otherwise these faults

    will spoil the appearance of the garments.

    Vertical faults usually result from knitting process but can

    occur with finishing. A common vertical fault is needle line.

    Faulty needles result in vertical lines of occasional or

    frequent tuck stitches. Such faults in garment blanks or fully-

    fashioned panels render them unusable.


    The knitting industry uses oils to lubricate machinery in the

    immediate vicinity of where the fabric is being produced, i.e.,

    on the needles themselves. Such oils mixed with

    atmospheric dust and metallic powder can, in certain

    circumstances, cause stains on the fabric or garments being

    knitted. Two procedures are used to minimize this:

    1. Control of oil itself, by applying in minimum quantities and

    delivering it quickly, so that it is present in fabric but does not

    show up in any build up of soiled material that would result from

    spasmodic application;

    2. Using oils that are readily mixed with water, so called scour able

    or clean oils.

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    The majority of knitted piece goods are wet finished before

    cutting and there is little likelihood that oil staining will remain

    in finished fabric. On stitched shaped garments it can present

    major problems if tight control is not exercised in the knitting

    room. As these garments are not generally wet finished,

    stains are usually dealt with during examination by solventbased spotting guns. The problem is negligible in fully-

    fashioned industry where oil is not used on the needles and

    where wet finishing is usual.

    Stains due to oil on knitted fabrics show as dirty areas, or

    horizontal markings, associated with a course or group of

    courses, or vertical lines following one or more wales and

    fading away with distance.

    Other stain characteristics of knitted fabrics occur when

    accumulated lint (fibre dust0 falls into knitting zones and gets

    incorporated into the fabric. Some circular machines are

    equipped with vacuum or blower devices to clear the

    immediate vicinity of the knitting zones. Such devices are not

    usual on flat machines and good housekeeping during theknitting process is essential.

    Cleaning down is particularly important where the knitting of

    light coloured fabric and garments occurs after the knitting of

    darker coloured fabrics. Similar problems occur if coloured

    fabrics/garments pieces are knitted in the same location as

    white or pastel coloured ones.

    Some faults in knitted fabric and garments are only detected

    when the garment is in use. One such fault, common to all

    textiles, is fading of colour. The other problem that occurs

    infrequently is pilling.


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    Pilling is the formation on the surface of knitted fabrics of

    small balls of abraded fibre. It is connected with several


    1. The type and size of fibre mixture used in the component yarn;

    2. The construction of yarn in terms of twist factor;

    3. The type and tightness of knitted construction;

    4. The nature of the surface against which the knitted fabric has


    Wool pills are considered weak and indeed sometimes drop

    off spontaneously. Pills produced in fabric containing

    polyamide or polyester fibres are considered strong and

    persist, making garments on which they occur unsightly un-

    wearable, even though not worn out.

    Testing procedure involves tumbling samples in pill drums or

    pillboxes where they are abraded against both standard

    surfaces and against selected fabrics.

    Pilling, which is particularly deleterious phenomenon in

    knitted garments, has also been discussed, with indications of

    the factors involved in its formation but no magic, one-off


    Knitted fabric standards

    The standard for basic fabrics (including but not

    limited to finished single knit, rib, terry, double knit

    and interlock fabric) is determined as under.

    1.7.1 Four-Point System

    Penalty points are assessed to a piece of fabric

    according to the length of defects measured in

    inches. The following schedule of penalty points is

    based on fabrics 60-62 inches in width for defects

    visible when inspected on face side of the fabric


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    3 inches of less 1

    Over 3 but not over 6 inches 2

    Over 6 inches but not over 9 inches 3

    Over 9 inches 4

    a. Four penalty points per linear yard are the maximum

    assessable for fabrics up to 60/62 inches in width.

    b. For fabrics over 60/62 inches in width, maximum penalty

    points are to be increased in proportion as the width

    exceeds 60 inches.

    c. Regardless of the length of the fabric, the quality shall be

    expressed in the number of penalty points per 100-yard

    length. (Example: a 20-yard piece with 3 penalty points is to

    be rated as 15 points per 100 yards.)

    This method of evaluating quality relates only to:

    a. Knitting defects

    b. Grease oil spots

    c. Dye spots

    d. Stains

    e. Slubs except where they are an inherent part of the


    f. Bars

    Fabrics are to be examined for these defects on the face side.

    Other than these a fabric may be rejected or downgraded if it

    does not meet specifications of the user.

    Basic fabrics shall be classified as first quality if the number

    of penalty points does not exceed 40 points per 100 linear

    yards. However the maximum number of defects may not

    exceed 30 per 100 yards.

    1.8 Knitted Garment Quality

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    Defects in knitted fabrics were discussed in the previous

    chapter. Faults incurred during the knitting and fabric-finishing

    processes pass on to the knitted garment itself unless

    detected and removed during fabric inspection. During the

    progress of garment assembly of fully cut pieces or knitted

    pieces additional faults can be accumulated. These faults may

    occur during cutting, seaming or garment finishing. The

    number of possible faults increases with the number of

    processes that a garment passes through. It follows,

    therefore, that fully cut garments have the greatest fault

    potential and some fully-fashioned garments the least, with

    stitched shaped cut falling in between.

    For example a knitted sock cannot contain dimensional faults

    arising from cutting, nor multiple seaming problems becauseit is neither cut nor much of the seamed. All the faults in a

    sock can be classified as knitting or yarn faults or

    dyeing/finishing faults. In contrast, a fully-fashioned garment

    may have a dimensional abnormality, knitting defects due to

    yarn faults, and fully cut garments may have dimensional

    faults, seaming defects, yarn & knitted faults along with

    finishing defects.

    So a comprehensive quality control procedure is required to

    check faults at all stages, to avoid cumulative faults.

    Since fully cut garments pass through all the stages of

    garment manufacturing, so quality control procedures

    applicable to this process will cover most of the peculiarities

    of knitted garments.

    Yarn quality assessment

    In a knitted fabric & garment integrated company fabrics for

    fully cut garments are mostly produced within the company

    itself and the company procures yarns from some spinning

    unit. Therefore it essential to periodically check the quality of

    the in coming yarns. Where deliveries of yarn are from

    various spinners, more intensive sampling and testing is

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    Normally spinners send a quality check report with each

    delivery of the lot, however, if not received it may be

    demanded from the spinner. Many knitting and garment

    manufacturing factories do have equipment to check qualityof the yarn and they rely on the quality reports of the


    A company consuming large amount of knitting yarn for

    circular machines should possess some basic testing

    equipment to check the quality of the yarns. Specification of

    incoming raw materials is one of the most neglected areas of

    knitting. The company should also have its standards of yarn

    quality specifications. Testing of yarns implies that

    specifications have been established against which to test.

    Some basic but important factors to specify in knitting yarns


    Yarn Count;

    Count variability

    Yarn Evenness;

    Single & doubling twist;

    Twist variability

    Yarn strength;

    Other than above, some yarn characteristics associated with

    the fibres types are important, such as fibre diameter in wool,

    the extent of presence of trash and seed contamination in

    cotton, the residual bulking in acrylic yarn, and crimp rigidity

    in textured polyester and polyamide yarns.

    Some or all of the tests may be carried out routinely, while

    others may be only performed on suspect lots. The objective

    of maintaining yarn standards is to produce fabric that meets

    the specification laid down. As narrated in earlier chapter, all

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    aberrations in yarn specifications produce measurable or

    visible faults within the fabric.

    A knitwear designer should understand these factors in

    knitting yarns and its effect on fabrics quality. It is not the

    duty of the designer to check the yarn or fabric quality, butthey can advise and suggest to the quality control department

    to check certain yarn quality specifications.

    Fabric quality assessment

    Knitted fabric is usually examined at two stages:

    After knitting and

    After finishing.

    But the quality control procedures start before and

    during knitting;

    Before knitting, the machine is correctly set

    for stitch length and feed tension to

    produce a particular quality, and

    During knitting to check that quality is

    being maintained and fabric damages are

    not occurring due to needle or yarn


    Thus a knitting operator also acts as quality controller to

    prevent the knitting machine producing faulty fabric. The

    rough examination after knitting is to ensure that the fabric is

    not being produced with visible faults that by feedback can be

    rectified on a particular knitting machine. At this stage, some

    rough mending may be carried out to rectify minor faults to

    prepare the fabric for the dyeing and finishing process.

    After finishing, the fabric is examined over an examination

    table, faults are identified and their location marked so that

    they can be dealt with during spreading or after cutting. In

    order to locate defects at the spreading and cutting table, it is

    usual practice to mark at the selvedge with coloured tag or

    put a sticker.

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    Fault counts can be maintained to assess improving or

    deteriorating standards. Visual fault location cannot be 100%,

    neither can an operative act other than subjectively, and

    checks on the examiners also need to be carried out.

    In-process quality control

    Quality control during spreading

    The operatives who prepare the fabric-lay are also

    responsible for quality control of the operation, whether they

    are spreading by hand or machine. During fabric spreading

    care need to be taken to avoid stretching or distortion, in

    particular that of knitted fabrics, which are more prone to

    stretching. Faults marked in earlier examination must be

    located and decision made about them as regards eliminatingthem from the lay.

    Alignment of features and patterns of the fabrics must be

    maintained where necessary. Also of great importance is

    ensuring that the number of layers in the entire lay, and the

    sub-numbers of particular colours or patterns, are correct.

    Again, procedures must be established to check that this is


    The accuracy of the marker and its positioning on the lay, or

    the marking of the pattern pieces on the top layer, must be

    the subject of close quality control. Dimensional problems

    can be induced at this stage, as can misalignments of

    garment portions or misalignment of patterns within or on the

    fabric. Another common mistake at this stage is to forgetmarking one or more pieces of the garments, say pockets or

    plackets, which can cause problem of mismatch if cut from

    different lay.

    It is also important to identify and label on the marker the

    relevant sizes of the garment portions, so that after cutting

    they are assembled in the correct bundles.

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    Quality control during cutting

    When cutting by hand with straight knives care should be

    taken not to deform knitted fabric, particularly within the

    depths of the lay. While the cutter is apparently following the

    surface marker, the lower layers, which are not properly

    aligned or deformed, are not necessarily being cut accurately.

    Some fabrics are particularly difficult to cut, e.g. 1 x1 rib, and

    the problem increases with depth of the lay. To cut these

    fabrics lot of skill is required on the part of the cutter. Other

    faults of bad cutting are the failure to accurately follow lines of

    the marker, and the cutting off of corners.

    Auto spreading and cutting pose less of a problem but it must

    not be assumed that they are infallible. Constant checking by

    sampling must be carried out to ensure good standards.

    Measures must be taken to ensure that the bundles

    assembled after cutting contains the correct number of pieces

    and that faulty pieces have been identified and removed. In

    one cut operations and bundle making all the pieces must befor the same size garment.

    Quality control during sewing

    Knitted garments, which are assembled by overlocking, pose

    problem. The over locking machinery actually cuts off the

    edge of the fabric to ensure a fixed dimension of bite.

    Patterns for knitted garments often contain an allowance for

    cutting by the overlock knife, which varies from 3mm to 6mm

    bite. If care is not taken a careless overlocker can readily cut

    20mm off a particular edge, altering the dimensions of the

    garment considerably.

    Other problems arise from the difficulties of controlling

    alignment of two components (say, back & front panel) during

    overlocking. Because knitted fabrics stretch it is easy for one

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    of the components to stretch during seaming. Subsequent

    attempts at correction within the length of the seam make

    matters worse and the garment shows obvious distortions.

    Even slight misalignments at cuff and waistband ribs can be

    visually unacceptable.

    The most difficult task for overlockers, cup seamers and flat

    seamers alike, is maintaining alignment of stripes or patterns

    on side seams. It is usual to select the most skilled operatives

    and to pay premium rates. Stripes and patterns are more

    usual on cut stitch shaped knitwear and overlockers in the

    knitwear industry gradually gain the skills necessary to deal

    with them.

    The other common problem with overlocker seams in

    particular is distortion by general stretching during seaming.

    This shows as bowing or seam rippling. However, some or all

    of this is recoverable during finished steaming.

    The above factors that affect quality, and need to be subject

    to control, relate to the operative and his/her skills ofassembly. Such factors are best dealt with thorough training,

    rather than through checking. The best quality control

    processes are built into the production system. Make well

    and there is little need to check.

    Other seaming factors relate to machine settings. Some

    customers specify stitches per centimeter or inch and this

    must be measured. The machine builders graded marks

    (stitches/unit) indicated on the machines are only

    approximations, not very accurate quantities. Where

    customers do not set the standard the manufacturer must set

    the standards appropriate to his particular quality perception.

    Seam balance is important in seams using more than one

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    thread. For knitted garment seams this in particular means

    overlock seams and multithread chain stitches. It is strongly

    advocated that thread run in is used as an assessment of

    balance, rather than mere visual appearance. The single and

    double chain stitch in particular, incorporated in the collar

    seams; bear the load when the seam is stretched. Optimum

    values for thread run-in must be established and maintained

    to avoid customer complaints of seam failure.

    Final Inspection

    All knitted garment manufacturers have final inspection

    procedures to ensure that the quality they promise to

    customers is maintained. Analysis of the records of final

    inspections should also provide suggestions to the

    production section for action to improve quality. Examination

    results in garments being categorized into firsts, seconds andrejects.

    Firsts pass, are sent straight away for packing. Seconds may

    be mended or the fault repaired in some other way, such as

    stain removal, loose threads tidying, stitch mending etc.

    Having corrections done, they move after re-examination into

    first category if corrections are satisfactory. Likewise a major

    rejection fault may be overcome to move the garment into

    second category.

    Very few companies allow absolute rejects to occur in their

    production process, and such events are usually associated

    with an unrecognized problem with the raw material, such as

    excessive pilling, dye fading, dye bleeding etc. Some faults,

    although measurable, are actually assessed visually.Examples include colour matching, colour variation between

    components, dimensional distortions and misalignments.

    Other faults more obviously fall into the subjective category

    and pose difficulties in definition of their severity. Holes of all

    sizes usually result in rejection and may be subjected to

    mending that brings them into a second category. More

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    difficult to categorise are flaws due to thick and thin localized

    irregularities in yarn that may occur in an unobvious place in

    the garment. Tidiness of make up is also judged at this stage,

    with loose sewing threads, fragments of threads and trailing

    overlock chains all tending to lower the perceived quality of

    the garment.

    Such subjective judgments are not normally written into a

    garment specification but are covered by the premise that if

    the garment was passed and sold the customer would return

    it. This leads to another concept, of different qualities for

    different customers. Manufacturers of knitted garments gain a

    feel for what a particular customer/market will tolerate, and

    adjust accordingly.

    Dimensional & design Considerations

    Measuring the dimensions of knitted garments poses

    particular problems. These have already been aired earlier in

    this chapter. The act of measuring itself is difficult. Handling

    and placing a knitted garment on a flat surface can induce

    stretch of up to 5%.

    The edges of knitted garments can be indeterminate and of a

    rounded fold rather than a precise, crisp edge. Tolerances of

    width measurement need to be generous and related to more

    absolute quantities such as a total number of wales.

    Widths of waistbands, cuffs, collars and facings of knitwear

    are commonly expressed in terms of the number of ribs, but

    only on the coarsest gauges can the ribs be counted easilyduring production.


    Weight of a garment can be used as a quality control measure

    to assess overall variability. It is particularly useful in the

    fully-fashioned industry. Used in conjunction with control

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    chart it enables a selection to be made of garments that fall

    outside control limits, for further examination.

    Weight control charts also highlight trends towards higher or

    lower limits that occur in production processes.

    Weight is also useful during production to assess the

    variability of cutting process and of garments length or piece

    knitting. In such usage the two interacting factors of yarn size

    and loop length are being assessed as well as the state of


    Design Factors

    In any market dealing with clothing, visual design itself is

    considered a quality. It must be recognized that hitting the

    right design for the market often overrides considerations by

    the ultimate customer of such factors as durability, fitness for

    purpose, neatness of make up and other utilitarian factors.

    Good design must be considered a very important tool in the

    armoury of quality assurance.

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