Nesrin Sahbaz Karaduman

By Kadir Bilisik, Nesrin Sahbaz Karaduman and Nedim Erman Bilisik

Two dimensional (2D) woven, braided, knitted and nonwoven fabrics have been used for the fabrication of soft and rigid structural composite parts in various industrial areas. However, composite structure from biaxial layered fabrics is subject to delamination between layers due to the lack of through-the-thickness fibers. It also suffers from crimp which reduces the mechanical properties. Triaxial fabrics have an open structure and low fiber volume fraction. However, in-plane properties of triaxial fabrics are more homogeneous due to bias yarns. A 3D woven fabric has multiple layers and is free of delamination due to the z-fibers. However, 3D woven fabric has low in-plane properties. Three dimensional braided fabrics have multiple layers and they are without delamination due to intertwine type out-of-plane interlacement. However, they have low transverse properties. A 3D knitted fabric has low fiber volume fraction due to its looped structure. A 3D nonwoven fabric is composed of short fibers and is reinforced by stitching. However, it shows low mechanical properties due to lack of fiber continuity. Various unit cell based models on 3D woven, braided, knitted and nonwoven structures were developed to define the geometrical and mechanical properties of these structures. Most of the unit cell based models include micromechanics and numerical techniques.

Part of the book: Non-woven Fabrics

By Nesrin Sahbaz Karaduman, Yekta Karaduman, Huseyin Ozdemir and Gokce Ozdemir

Textile-reinforced composites are increasingly used in various industries such as aerospace, construction, automotive, medicine, and sports due to their distinctive advantages over traditional materials such as metals and ceramics. Fiber-reinforced composite materials are lightweight, stiff, and strong. They have good fatigue and impact resistance. Their directional and overall properties can be tailored to fulfill specific needs of different end uses by changing constituent material types and fabrication parameters such as fiber volume fraction and fiber architecture. A variety of fiber architectures can be obtained by using two- (2D) and three-dimensional (3D) fabric production techniques such as weaving, knitting, braiding, stitching, and nonwoven methods. Each fiber architecture/textile form results in a specific configuration of mechanical and performance properties of the resulting composites and determines the end-use possibilities and product range. This chapter highlights the constituent materials, fabric formation techniques, production methods, as well as application areas of textile-reinforced composites. Fiber and matrix materials used for the production of composite materials are outlined. Various textile production methods used for the formation of textile preforms are explained. Composite fabrication methods are introduced. Engineering properties of textile composites are reviewed with regard to specific application areas. The latest developments and future challenges for textile-reinforced composites are presented.

Part of the book: Textiles for Advanced Applications

By Yekta Karaduman, Huseyin Ozdemir, Nesrin Sahbaz Karaduman and Gokce Ozdemir

Natural fiber–reinforced biocomposites are increasingly used in various industries such as automotive, construction, biomedical, and recreation, thanks to their distinctive advantages over traditional glass fiber–reinforced plastics. Natural fiber composites are sustainable, environmentally friendly, low cost, low density, and easy to process as well as have high mechanical properties. The quality of fiber-matrix interface is of critical importance since it determines the load distribution capability of the material. The interface between natural fibers and polymer resins has always been problematic because of the low compatibility between cellulose-based hydrophilic natural fibers and hydrophobic polymer resins, which leads to poor fiber-matrix adhesion and therefore inefficient load distribution between fibers and matrix. To date, several interfacial modification methods have been implemented to address this issue and improve the properties of the resulting composites. This chapter focuses on the interfacial modification of hemp fiber–based composites. First, hemp fiber structure and the nature of fiber-matrix interface were explained. Mechanisms of fiber/matrix adhesion as well as qualitative and quantitative methods for the determination of interface strength were outlined. Finally, the interface modification methods for hemp fiber–reinforced biocomposites were presented in the light of scientific literature.

Part of the book: Natural and Artificial Fiber-Reinforced Composites as Renewable Sources