Dynamic Wicking Process in Textiles

Abstract

We investigate wicking in textiles using neutron radiography on fabrics of two types, woven and simple jersey knit, and made of yarns of four different materials: cotton, polyethylene terephthalate, polyamide and polypropylene. Moisture distribution in the samples is quantified from the images, and the total mass is compared with gravimetric measurements for validation. The position of the front versus time is obtained from segmented neutron images and backlight images, with good agreement between the two measurement methods. Using a power law to fit the height versus time curves, values for the wicking ratio are found to depart substantially from the 0.5 predicted by the Lucas-Washburn equation. The sharp front approximation is found to be a good approximation for slow wicking fabrics but is an incomplete description of the moisture on high absorbing fabrics such as cotton. The variation of yarn material is the main contributor to the difference of wicking ratio among samples. Finally, neutron moisture profiles complemented with X-ray tomography allow to differentiate two regions in cotton wetted by wicking: intra-yarn wetting and wetting covering the yarns and the inter-yarn voids.

Effect of Weaving Structures on the Water Wicking–Evaporating Behavior of Woven Fabrics

“…The curve is divided into two parts, describing the fabric from imbibition to evaporation: Phase I, unsteady wicking and evaporation in the initial 10 min with water transfer speed S 1 ; Phase II, steady wicking-evaporating from 10 to 120 min with water transfer speed S 2 . The whole observed process is in good accordance with that in previous research [7,21].…”

“…As a widely used wicking measurement method, the strip vertical wicking test was first proposed by Ghali [6]. Previous studies focused mostly on physical models [7,8] and measurements [9,10] of wicking behavior in yarn and textiles and took the maximum wicking height/distance as a key moisture transfer index [11][12][13][14][15][16][17][18]. It was previously observed that wicking and evaporation occur simultaneously when a fabric is partly immersed in water [19] as illustrated in Figure 1.…”

“…Water transfer behavior is highly related to the geometry of fabrics [24], which depends on the density, weaves, thickness, and porosity [11,14,15,25]. The porosity of fabrics, determined by the structural weave [26,27], could induce changes in the structure, shape, and the number of capillary channels through the inter-fiber and inter-yarn pores [7,8,28], which affects the moisture transfer at various levels of capillary force [4,24]. It was found that the float and interlacing point, which are the two elements in a weave, can increase the whole water transfer to a certain degree [13,29].…”

Spontaneous Imbibition in a Square Tube With Corner Films: Theoretical Model and Numerical Simulation

“…Spontaneous imbibition, where a nonwetting fluid is displaced by a wetting fluid by capillary forces, in porous media is a common phenomenon encountered in many scientific and engineering processes (C. Li et al., 2019; Meng et al., 2017; C. Z. Qin & van Brummelen, 2019; Schmid & Geiger, 2012), such as oil recovery (Morrow & Mason, 2001; Y. Yang et al., 2019), filtration in soil (Kao & Hunt, 1996), wicking in textiles (Parada, Derome, et al., 2017; Parada, Vontobel, et al., 2017) or paper‐like materials (Z. Liu et al., 2018), and so on. In order to analyze the underlying mechanisms of spontaneous imbibition, porous media are usually simplified such that they consist of regular shaped capillaries (Cai et al., 2014), including cylindrical and angular tubes.…”

A Biomimetic Transpiration Textile for Highly Efficient Personal Drying and Cooling

“…[ 1–3 ] For example, commercial moisture‐wicking textiles have attracted tremendous attention because of their ability to cool the human skin by extracting the excessive sweat, through water transport and heat dissipation. [ 4,5 ] These textiles have been extensively studied and possess a strong capillary force inside the inter‐fiber channel which extracts the sweat rapidly from the skin to the outer environment for fast evaporation, such as the Coolmax fabric composed of profiled fibers [ 6,7 ] and directional water transport fabric with asymmetric wettability. [ 8–11 ] However, limited progress has been made in improving heat dissipation during sweat release, which can lead to heat stress during perspiration, especially in the hot and humid environment.…”