Structure/function analysis of nonwoven cotton topsheet fabrics: multi-fiber blending effects on fluid handling and fabric handle mechanics

Authors: Easson, Michael; Edwards, Judson - Vince; MAO, NINGTAO - University Of Leeds; CARR, CHRIS - University Of Leeds; MARSHALL, DAVID - University Of Leeds; QU, JIANGUO - University Of Leeds; Graves, Elena; Reynolds, Michael; Villalpando, Andres; Condon, Brian

Submitted to: Materials
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/8/2018
Publication Date: 10/24/2018
Citation: Easson, M., Edwards, J.V., Mao, N., Carr, C., Marshall, D., Qu, J., Graves, E., Reynolds, M., Villalpando, A., Condon, B. 2018. Structure/function analysis of nonwoven cotton topsheet fabrics: multi-fiber blending effects on fluid handling and fabric handle mechanics. Materials. 11(11):1-17. https://doi.org/10.3390/ma11112077.
DOI: https://doi.org/10.3390/ma11112077

Interpretive Summary: When different fibers are blended in a nonwoven material in different ratios they can exhibit differences in feel and fluid handling performance. This manuscript explored ten nonwoven fabrics, each with a unique blend of four fiber types, with the goal of further understanding the role that each fiber type plays in the overall feel and fluid handling performance.

Technical Abstract: Greige cotton has attracted interest in recent years as a highly functional fiber for use in nonwoven topsheet materials and has been shown to impart favorable fluid management and sensorial properties associated with function and comfort in wearable incontinence nonwovens. Nonwoven greige cotton has material surface polarity, moisture, and aspects of molecular structure that impart positive fluid management and fabric hand softness/formability properties. However, a complete understanding of the connection between functionality and compositional aspects of molecular, mechanical, and material property design is still required to prepare functional materials beyond a priori design. Thus, this study focuses on linking key fundamental indices of function to nonwoven composition design based on molecular and mechanical structure characteristics. Greige cotton, polypropylene, bleached cotton and polyester fibers were hydroentangled at 60, 80, and 100 bar. Electrokinetic and contact angle measurements were performed to assess surface molecular structure in light of the effect of material surface polarity on fluid management. Fluid management properties of rewet, strikethrough, and fluid handling (rate and efficiency of transport to the absorbent core) are characterized for hydroentangled nonwovens at greige cotton/polypropylene ratios (40-90%), and revealed close functional compliance with a commercial prototype. Using the Leeds University Fabric Handle Evaluation System, which is an objective evaluation based on measurements of fabric buckling deformation, the materials were tested for total fabric handle values (TFHV). Improvement in softness and formability are identified as optimal within a balanced range of blended fiber ratios. Associated fabric hand properties elicited from greige cotton preparations were found to be based on ratios of hydrophobic and hydrophilic fibers, and the blending of polyester and bleached cotton in low percent levels (5% or less) was found to influence sensorial properties. Otherwise, the hydrophobic/hydrophilic/fiber ratios may be associated with fluid management and tactile troperties and are correlated to wettability, moisture content, flexibility, and softness. Thus, assessment of connections between structure and function of materials designed with topsheet functionality using greige cotton, polypropylene, bleached cotton and polyester fibers provide insights into optional fiber blending in the design of materials with select sensorial and fluid handling indices.