Bicomponent fibres Sheath (nylon6), Core (nylon66)

Non woven textiles take advantage of the properties of synthetic fibres and are used in applications where low cost, large area coverage is needed such as in geotextiles, roofing felts and filters. The netting material, used to protect plants from birds or frost, that is found in garden centres, is an example of a non woven textile. Many household disposable cleaning cloths are also non woven textiles. Thermal bonding or stitch bonding is frequently used in their construction.

Single component or bi-component fibres can be used in thermally bonded non woven textiles to provide mechanical strength to the product. Hot calendaring is a method commonly used to achieve this bonding where the fabric is pressed between heated metal rollers which have an embossed pattern on them. This gives rise to point bonding as shown in the images. Bi-component fibres are made by extruding two compatible polymers that have different properties. Many different types of cross sectional geometries can be spun though the most common is the sheath/core structure where the core polymer is more crystalline and has a higher melting point than the sheath polymer. This allows the sheath polymer to melt in a thermal bonding process whilst the core polymer is unaffected, adding more strength to the finished product. Because the two polymers have different degrees of crystallinity, they also take up dye differently and this allows their structure to be seen when cross sections are examined in an optical microscope.