Textile fibers physical properties

The properties of textile fibers may be conveniently divided into three categories geometric, physical, and chemical, as shown in Table 4. 

Physical Properties. Relationships between fiber properties and their textile usefulness are in many cases quite obvious. Since fibers are frequently subjected to elevated temperatures, it is necessary that they have high melting or degradation points. It is also necessary that other fiber properties be relatively constant as a function of temperature over a useful temperature range. 

With the exception of glass fiber, asbestos (qv), and the specialty metallic and ceramic fibers, textile fibers are a class of soHd organic polymers distinguishable from other polymers by their physical properties and characteristic geometric dimensions (see Glass Refractory fibers). The physical properties of textile fibers, and indeed of all materials, are a reflection of molecular stmcture and intermolecular organization. The abiUty of certain polymers to form fibers can be traced to several stmctural features at different levels of organization rather than to any one particular molecular property. 

W. E. Morton and J. W. S. Heade, Physical Properties of Textile Fibers, 2nd ed.. The Textile Institute and Butterworths Scientific Pubhcations,... 

The properties of textile fibers can be divided into three categories geometric, physical, and chemical, which can be measured with available methods (15—17). Perceived values such as tactile aesthetics, style appearance of apparel fabrics, comfort of hosiery, as weU as color, luster, and plushness of carpets are difficult to quantify and are not always associated with the properties of the fiber, but rather with the method of fabric constmction and finishing. 

As is known of glass fiber-reinforced plastics, the mechanical and physical properties of composites, next to the fiber properties, and the quality of the fiber matrix interface, as well as the textile form of the reinforcement primarily depend on the volume content of fibers in the composite. 

Most plant and animal materials contain natural fibers that have been concerted into useful fibers for thousands of years including ropes, building materials, brushes, textiles, and brushes (Table 18.6). Animal protein fibers such as wool and silk are no longer competitive with synthetic fibers with respect to cost but are still often utilized in the production of high-end rugs. Some of these rugs are hundreds of years old yet retaining their color and physical properties. 

Matthews H.R. Mauersberger, Textile Fibers Their Physical, Microscopical and Chemical Properties , J. Wiley, NY (1947)... 

Graft and block copolymers of cotton cellulose, in fiber, yam, and fabric forms, were prepared by free-radical initiated copolymerization reactions of vinyl monomers with cellulose. The properties of the fibrous cellulose-polyvinyl copolymers were evaluated by solubility, ESR, and infrared spectroscopy, light, electron, and scanning electron microscopy, fractional separation, thermal analysis, and physical properties, including textile properties. Generally, the textile properties of the fibrous copolymers were improved as compared with the properties of cotton products. 

Crystallinity and disorder are important structural parameters for understanding relationships between structure and physical properties. Flaws and distortions are the main features that limit the ultimate properties of textile fibers. Some of these crazes, cracks and voids are revealed under the electron microscope, either on the surface or in cross sections stained with heavy metals (J, 2). However, these staining techniques (that reveal the main morphological features) make it much more difficult to determine the degree of distortion of the crystalline fraction. Theoretically, line profile studies permit separation of effects due to crystalline size from those due to structural distortions. However, the lack of peaks in semicrystalline fiber x-ray patterns hinders that approach. 

Summaries of chemical and physical properties of different polyester fibers are available (107). Polyesters display excellent resistance to conventional textile bleaching agents and are most resistant to cleaning solvents (107). Mold, mildew, and fungi may grow on finishes applied to polyester fabrics but do not attack the fiber itself (3). Again, insects that devour natural fibers normally do not affect polyester fibers although they may cut their way out of the fabric if trapped. 

TABLE 12.1 Typical (Average) Values of Tensile and Physical Properties of Some Textile Fibers... 

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