Fibre modifications

To some extent the conditions during extrusion influence the nature of the modifications. For example, an additive may not withstand the temperature of the extrusion process or the solvent used in the process.

Synthetic polymers may be produced as very fine microfibres, giving enhanced flexibility, wicking and liquid water repellency coupled with water vapour permeability. They may be made more hydrophilic by the incorporation of "water attracting" co-polymers. The handle and light reflecting properties may be modified by changing the cross-sectional shape, for example trilobal, pentalobal and octalobal filaments. Liquid water wicking may be enhanced by the use of microfibre filaments or tetra-channel filaments assisted, possibly, by the use of appropriate hydrophilic surface finishes. Low pilling products using a fibre which is weaker than standard materials have been developed. Hollow channels may be introduced to increase thermal insulation. Co-polymers may be introduced to give dye variant fibres. Soil release and flame retardent products are also available.