Chapter X Nonwovens in absorbent materials

Abstract

Two characteristics of nonwovens make them particularly suitable for use in an absorbent structure—high bulk for imbibing and holding large amount of fluid per unit mass of material and low cost of converting raw material into final product. Several other properties that have significant impact on the use of nonwovens in an absorbent fabric are disposability, comfort, and ease of fabrication of the absorbent product. The important role played by nonwoven materials in commercial absorbent structures has resulted in increased consumption of disposable nonwovens and absorbent products in the recent years. In discussing nonwovens, consideration must be given to the interrelationships of the four major structural elements that influence absorbency—(1) constituent fiber, (2) assembly structure; the web properties resulting from the nature of the fiber assemblage, (3) type of bonding; the chemical or mechanical means of conveying integrity to the fibrous web, and (4) finish; chemical and/or mechanical treatments conveyed to the formed and bonded web. Each of these factors can have an effect on the absorbency of the resulting structure. The wetlaid or wet form nonwoven process is derived from the paper industry and bears a considerable resemblance to the normal Fordrinier paper manufacturing process.