Multilayer or multicomponent composite nonwoven structures provide great advantages for many technical applications. Spunbond-meltblown-spunbond (SMS) type multilayer nonwovens have significant commercial success in terms of end-use versatility. SMS type composite nonwovens, which can be produced with both continuous and discontinuous production technologies, are evolving day by day. Bulky, fibrous, porous nonwoven structures are widely used as sound absorbers for a variety of applications for instant building and automotive insulations, machine insulations, etc. The fibers interlocking in nonwovens are the frictional elements and provide resistance to acoustic wave motion. As many researchers reported, the most effective factors on sound absorption properties of fibrous materials are fiber diameter, airflow resistance, material thickness, tortuosity, porosity, and fiber surface area. In this research chapter, the sound absorption performance of SMS type composite nonwovens in relation to air permeability and pore sizes has been determined. The results show that SMS type nonwovens perform sound insulation at high frequencies. Spunmelt nonwovens with the advantages of short production line will create various alternatives with varieties of layering and compete with commercially used other sound absorbers.
Part of the book: Engineered Fabrics
Smart textiles are one of the areas that provides added value to textile materials. It is a sector that has been developed with new technologies, new fibers, and textile materials. The production of smart or intelligent textiles cooperate with other branches of science like nanotechnology, materials science, design, electronics, and computer engineering, etc. Smart textiles are classified into three groups as passive smart textiles, active smart textiles and ultra smart textiles according to their performance characteristics. Passive smart textiles are the first generation of smart textiles and sense the external conditions; for instance, UV protecting clothing, conductive fibers, etc. As active smart textiles respond to external conditions, ultra smart textiles sense, react, and adopt themselves to conditions. Shape memory materials, chromic materials, heat storage, and thermo-regulated fabrics are the typical applications of active smart textiles.
Part of the book: Advanced Functional Materials