Study of the Influence of Fiber Diameter and Fiber Blending on Liquid Absorption Inside Nonwoven Structures

The purpose of this work was to investigate how nonwoven fabrics absorb and diffuse liquids and to define relevant diffusion parameters, with a special focus on the influence of fiber diameter on the diffusion process. The nonwoven structures studied were composed of polyester fibers of different diameters and were manufactured with a drylaid/needlepunching process. The liquid diffusion properties were evaluated with decane, a perfectly wetting liquid. Two methods based on vertical wicking (one direction) and absorption capacity measurements were used. The vertical wicking test results showed that finer fibers led to higher capillary absorption ability, but to the detriment of liquid absorption rate. Blending two fibers of different diameters improved the liquid retention behavior, while maintaining absorption rates that were equivalent to nonwovens with the coarser fibers. Finally, the different results obtained in the two experimental methods for the liquid filling ratio are discussed.