*4.2.1 Effect of fabric parameters on wicking and its application as technical textiles*

Researchers have discovered that fabrics with equally distributed float wick slower and horizontally striped fabrics wick quicker. Because the floats of threads in

horizontally striped fabrics are positioned on the edge of the horizontal stripes and spread throughout the entire fabric surface, this happens. This uneven structure could explain why horizontally striped materials have a higher wicking rate. The pace of warp and weft way wicking differs slightly, and in some situations, the rate of weft way wicking is larger than the rate of warp way wicking. This could be caused due to tension differences between warp and weft threads. The rate of wicking for uniformly dispersed floats increases as weave factor P1 increases, which is due to the increase in floats in the fabrics [30]. Fabrics made of ring yarn wick faster than fabrics made of compact yarn [31]. Moisture management behaviour of knitted fabric has been studied from structurally modified ring and vortex spun yarn where the air permeability, water vapour permeability and total absorbency of the knitted fabric made from changed yarn all improved significantly, whereas the wicking characteristic decreased [32]. Fabrics composed of coarser yarns (40s Ne) wick more quickly than fabrics made of finer yarns (50s Ne). Fabrics behave in the same way that yarns do when it comes to wicking. The difference in wickability between plain weave and twill weave fabrics grows as the constituent yarn fineness increases. This variation is substantially more noticeable in diagonal wicking than in warp- and weft-way wicking [33]. The Lucas-Washburn equation was found to be suitable for analysing the wicking behaviour of woven cotton fabrics, and the wicking height square had a positive and good correlation with time in both the warp and weft directions, according to Zhu et al. [34]. Wicking height decreases with increasing weft yarn density as it leads to a decrease in porosity due to increased warp yarn crimp [35].

Using a sink time technique, the wettability of various terry towel fabrics was tested, and it was discovered that fabrics with higher loop density (repeat with 3-pick) sink faster than those with lower pick density (4, 5 and 6-pick weaves). Vertical wicking studies reveal that materials with a 3-pick density wick the fastest, followed by fabrics with 4, 5 and 6-pick density [36]. Moisture management is used in applications such as active athletics, exercise garments, work clothing, intimate apparel and footwear to avoid or limit liquid collection on the wearer's skin owing to perspiration. This is accomplished by rapidly wicking or diffusing the liquid through an inner hydrophobic fibre layer to an outside hydrophilic layer, then evaporating it into the atmosphere. Sportwool is a two-layer sportswear with good moisture management qualities that is utilised in a variety of sports apparel. The inner layer, which is closest to the skin, is made up of chemically treated ultrafine Merino wool fibres (˂20 μm). The exterior layer is completely constructed of polyester filament yarn. Wool fibres have a high-water vapour permeability, which allows heat and moisture to be transferred from the skin to the outside surface, where it can escape due to wind speed and body movement [37]. A multi-layer construction is appropriate for sportswear [38, 39]. According to D'Silva and Anand [38], in a two-layer construction, the wicking layer is made up of synthetic fibres, such as micro-denier polyester, while the absorbent and evaporating layer is commonly cotton or rayon.

Many healthcare and personal hygiene items require liquid flow management in terms of liquid volume and flow rate elements that are acceptable for the end use. The incorporation of effective capillary systems into the final product allows for controlled liquid flow. Hygiene goods are made up of different layers of materials with different properties that allow liquid or moisture to drain swiftly away from the inner surface of the material in contact with the wearer's body. Wicking and wetting principles are applied to multilayer protective clothing. The outer layer of protective clothing consists of permeable fabric or a liner or a layer made of carbon-loaded foam. To reduce the wetting due to body fluid, the outer layer is treated with a fluoro-chemical, and

*Absorbency and Wicking Behaviour of Natural Fibre-Based Yarn and Fabric DOI: http://dx.doi.org/10.5772/intechopen.102584*

this reduces the surface energy, and thereby, the wetting is reduced [40]. Geotextiles are permeable fabrics that can hold solid items in place while allowing water to pass through. Due to their low cost, consistent qualities and convenience of placement, they have been widely used as drainage, separation and filter materials in geotechnical and geo-environmental activities for about 30 years. The primary goal of geotextiles is to allow water to flow through the filter into the drain over the course of the project while keeping soil particles in place and avoiding migration through the filter [40]. Natural geotextiles are now being used such as jute geotextiles (JGT) where biodegradability of JGT is an advantage when control of surficial soil erosion is considered. It acts as mulch, attenuates extremes of temperature, adds micronutrients to the soil, leaves fibrous residues that improve hydraulic conductivity of soil and thus eases dissipation of pore water pressure [41].
