Measurement and Theory of Absorbency of Cotton Fabrics

Abstract

High and uniform absorbency of cotton fabrics is a desirable quality in nearly every wet- finishing operation and in many finished fabrics; yet absorbency-measuring tests which have been employed up to the present time are largely inadequate and arbitrary. A test method is described here which is more suitable in that it meets the requirements of wetting the fabric quickly from one side while it is under pressure and allowing the comparison of different fabrics in a readily understandable manner. Using a glass filtering funnel to provide a wet porous plate and a flowmeter for measuring rates, the apparatus is easily assembled and calibrated. The test is simple and rapid and per mits numerical evaluation of both rate of absorption and total or ultimate absorption, largely independently of apparatus characteristics. The separate evaluation of these absorbency factors and the elimination of timing procedures set this test apart from those previously published. The method is readily adaptable to the investigation of many liquid-absorbent relationships. Application of the test to the evaluation of absorbency of purified cotton fabrics has led to a plausible explanation of their absorption behavior as being due largely to spaces within the fabric rather than to absorption characteristics of the fiber itself.

Wetting and Wicking in Fibrous Materials

“…Various test methods are reported to measure transplanar wicking [5,9,33,105,[149][150][151]. A porous plate test is used to study transverse wicking.…”

“…The apparatus for the plate test is shown in Fig. 27 [5,9,150]; it consists of a horizontal sintered glass plate, kept moist by a water supply whose height can be adjusted so as to keep the water level precisely at the upper surface of the plate. A fabric is placed on top of this glass plate and draws water from it at a rate which depends on its wicking power.…”

“…Plate tests measure absorbency of fabrics, especially towels [109,150]. Some of the tests apply pressure to enhance the flow of liquid, but therefore deviate from a true wicking process.…”

Factors Contributing to Absorbency Behaviour of Pile Fabrics

“…The capillary force decides the way in which the liquid flows through pores. The absorbency characteristics of fibre assemblies depend on their geometry, especially surface roughness as well as pore size distribution (Buras et al, 1950;Nyoni & Brook, 2006). The amount of water absorbed by terry fabric is important for its end use.…”

Spontaneous Transplanar Uptake of Liquids by Fabrics

“…Over the years, this experimental problem has been attacked by numerous investigators [1,2,[4][5][6][7]9]. The improvements they achieved have been adequate for comparing performances of materials that are relatively sluggish absorbers, but the methods have not been satisfactory for dealing with very rapid absorption rates, nor were they sensitive enough to produce data that could be used to study the influence of the parameters that are thought to control the phenomenon.…”