Spreading of Liquids in Textile Assemblies Part II: Effects of Softening on Capillary Spreading

Abstract

The effects of softening agents on the wetting of textiles were investigated by measuring the capillary spreading of liquid as a function of time. The values of the exponent n during phase II of the capillary spreading of softened fabrics increased in comparison with those of unsoftened fabrics owing to the adsorption of the softening agent, which made the fiber surface more hydrophobic and produced a larger advancing contact angle of the fiber to the water (&thetas; A ). Based on experiments with DTAC as a softening agent for nylon, the following quantitative relationship was found between the value of the exponent n and the advancing contact angle of water (&thetas; A ): n = (4.62 X 10 -3 )&thetas; A , -0.001. From this, reasonable advancing contact angles were also estimated for other fabrics.

Wetting and Wicking in Fibrous Materials

“…When a liquid drop is placed on fabric, it will spread under capillary forces [11]. As suggested by Gillespie [12], the spreading process may be split conveniently into two phases, I and II, when some of the liquid remains on the surface and when the liquid is completely contained within the substrate, respectively, as shown in Fig.…”

“…Either the drop absorbency time [5,90] or the spreading rate of the liquid within the fabric is measured [11,12,96,97]. Wicking of minute drops of liquid has become very important for printing technology [154].…”

“…Kissa [13,96] therefore measured the area covered by the spreading liquid by a photometric technique. Kawase et al [11,158,159] used the image analysis studies for spreading of liquids in textile assemblies.…”

A new thermocouple technique for the precise measurement of in-plane capillary water flow within fabrics

“…The 10 seconds time scale was determined on the basis of measurement error and the stability of measured temperature. If the temperature at time t increases to 0.5°C at tT+0.5 in which the interval is more than 10 seconds, then the arrival time is defined as Equation (6). However, if the wetting heat is minimal compared with heat loss via evaporation, then the temperature at the flow front will decrease.…”

A review on advanced imaging technologies for the quantification of wicking in textiles

“…After this calibration, the lens system and the distance between the camera and the sample must be kept constant. Kissa 22 and Kawase et al 23 applied this method in their studies. In both cases, they placed a stopwatch in the camera's field of view, so the time could be attributed to each photograph of the developing wetted area.…”