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  • 2.9-COTTON VALUE ADDITION-FABRIC FORMATION

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  • Fabric formation

    Chapter 2 - Cotton value addition - Textile processing 

     
     

    Spun yarns can then be used in the formation and production of fabric. There are two main methods for creating fabric structures from yarn – weaving and knitting. Each structure has its own unique characteristics and end uses. For instance, denim is a woven fabric and T-shirts are usually knit fabrics.

    Woven fabric

    Weaving involves the interlacing of yarns at right angles, much like making a basket. Depending on the set-up of the loom, many weave patterns and fabric constructions can be produced. (See figures 2.41–2.43.)

    Figure 2.41: Diagram of a weaving loom
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    These elements of a loom show how a ‘sheet’ of warp yarns on the loom beam are fed into the harness heddles where they are alternately separated by an up-and-down motion in order to feed the weft, or filling, yarns perpendicular to the warp yarns. This continuous cyclical action creates the woven fabric structure.

    Figure 2.42: Woven fabric (plain weave pattern)

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    This SEM shows the interlacing/ basket-type configuration of the yarns in a woven fabric.(M.J. Grimson)

    Figure 2.43: Basic weave patterns 

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    These illustrations show examples of some basic fabric constructions.

    Knitted fabric

    Knitting involves looping the yarn or yarns around and through one another, much like hand knitting or crocheting (see figures 2.44–2.46).

    Figure 2.44: Circular weft knitting 
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    (A) Circular (weft) knitting produces fabric in a continuous spiral form from numerous yarn supply packages.
    (B) Latch needle function and loop formation of knitting.

     

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    Figure 2.46: SEM of knitted fabric

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    This SEM of knitted fabric shows clearly the looping configuration of the yarns which is the basis of most knit structures. (M.J. Grimson)

    Nonwovens

    Nonwovens are fabric structures created directly from fibre, bypassing the need for yarn formation. These fabric structures depend on thermal bonding, chemical bonding or mechanical entanglement for their integrity. Varied processes, chemistry, and machines are required, depending on the specific end-product desired and the technology employed. Common uses of nonwoven fabrics include products such as diapers, disposable wipes and feminine hygiene products.United States paper currency is a nonwoven product using some cotton fibre (see figures 2.47–2.48)

    Figure 2.47: SEM of a thermal bonded nonwoven fabric (M.J. Grimson)

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    Figure 2.48: SEM of a hydroentangled nonwoven fabric (M.J. Grimson)

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