Durable Nonwoven Fabrics via Fracturing Bicomponent Islands-in-the-Sea Filaments

This paper deals in general with fabrics consisting of bicomponent fibers that are fractured/fibrillated and bonded using mechanical and/or thermal means to form micro-denier fibers. Bicomponent filaments produced by the spunbonding process, where two polymers are co-extruded to form a fiber are used to demonstrate the feasibility of fracturing bicomponents. This process of nonwoven fabric manufacture combined with the fiber-fracturing process is discussed. These fabrics are processed using commercially accepted practices. Differences in the physical properties due to the different polymer ratios and cross-sections produced are discussed. In particular, this paper deals with the production of modified ‘Islands-in-the-Sea’ filament cross-sections that enhance the fracturing of such filaments to produce micro-fiber webs that have considerably higher surface area compared to their conventional counterparts. Point-bond calendered bicomponent samples were also tested for their mechanical properties with different island counts and polymer compositions. The optimal bonding techniques for the fabrics were identified. The role of the Islands-in-the-Sea fiber cross-section was demonstrated for optimizing the fabric strength and enhancement of surface area.