ABSTRACT
Among the fibers used widely for absorbent applications are cotton, pulp, and rayon, all largely cellulosic. One common attribute these materials provide is hydrophilicity which is needed in order to attract, imbibe, and hold fluid in the structure. Research of the past decade has shown that a second characteristic that plays a critical role in determining the amount of fluid absorbed and the rate at which it is imbibed is the resiliency of the web. This is governed by both the chemical and physical properties of the fiber and the structure of the web. For a given fabric structure, differences in resiliency of the fibers lead to differences in the absorbency performance. Work of the past few years has illustrated that webs containing cotton usually show superior absorbency values than do comparable webs containing rayon. This has been primarily ascribed to the fact that the wet resiliency of cotton is several times greater than that of rayon. When a hydrophilic fiber comes in contact with an aqueous fluid, the latter diffuses into the structure. It disrupts intermolecular bonds, reduces modulus, and causes a collapse of the fabric in terms of the thickness. This results in a reduction (1) in the interstitial space and, therefore, in absorbent capacity, and (2) in the pore size, and, therefore, in absorbency rate. In order to improve resiliency of a structure containing a hydrophilic fiber, studies have considered using blends, with the second material a synthetic fiber, either a polyolefin or a polyester [3,4], which absorb little or no fluid in the internal structure. This procedure has proved useful, particularly when the cellulosic fiber is rayon [6].
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