1.1 The outline of textile materials

The textile materials include various raw fiber materials which are used in textile and various products processed from textile fibers, such as the one-dimensional yarn, thread, rope, and so on; two-dimensional and shape-based fabrics, textile nets, flakes, and so on; and three-dimensional and form-based clothing, braids, utensils, and its reinforced composites. The basic textile processing process is shown in Figure 1.

As shown in Table 1, the textile materials are essentially different from traditional engineering materials; moreover, textile materials are flexible, easy to change their shape, and generally light weight; these characters can largely compensate the defects of engineering materials. According to the form, textile materials can be divided into fibers, yarns, flat fabrics, and three-dimensional fabrics. The fibers are spun to form the yarns, which are then weaved into the fabrics by weaving technology or knitting technology. In addition, the nonwoven fabrics are formed directly by winding the fibers.

#### 1.1.1 Fiber

The shape of fibers is flexible and elongate, with length (Figure 2) and diameter ratio (Figure 3) of more than 10<sup>3</sup> . Theoretically speaking, the fibers have round and

1.1.2 Yarn

1.1.3 Fabric

properties.

Figure 4.

the yarn.

Figure 5.

181

called the "thread" (Figure 4).

Electromagnetic Function Textiles

DOI: http://dx.doi.org/10.5772/intechopen.85586

The yarn is an elongated body having a certain strength and toughness, in which the fibers are arranged in parallel and are cohered or entangled by twisting or other methods. The yarn is an intermediate product of textile processing. A number of short fibers or filaments are arranged in an approximately parallel state and twisted in the axial direction to form an elongated object having a certain strength and linear density, which is called the "yarn." The strand of two or more single yarns is

A two-dimensional object having thin thickness, large length, and wide width formed by interweaving and interlacing textile fibers and yarns by a certain method is the flat fabric. There are a variety of fabrics (as shown in Figure 5); they could

According to the forming methods, the fabrics can be divided into woven fabric, knitted fabric, and nonwoven fabric. The woven fabric is composed by warp and weft yarns arranged perpendicularly to each other according to some organization rules. The knitted fabric is formed by the yarns bent into a loop. Nonwoven fabrics

Traditional textile materials are mostly dielectric materials and are important electrical insulation materials. The electromagnetic properties of textile materials include electrical conductivity, dielectric properties, electrostatic and magnetic

The morphology of one kind of the yarn. (a) The appearance of the yarn and (b) The distribution of fibers in

The type of the fabric. (a) Woven fabric; (b) Knitted fabric and (c) Nonwoven fabric.

have various materials, forms, colors, structures, and formation methods.

are reinforced by oriented or randomly arranged fiber webs.

1.2 Electromagnetic properties of textile materials

#### Figure 1.

Basic process of textile processing.


Table 1.

The difference between textile materials and traditional engineering materials.

#### Figure 2.

#### Figure 3.

The cross-sectional morphology of natural fibers. (a) Wool fiber; (b) Cotton fiber; (c) Silk fiber; (d) Hemp fiber.

slender bodies with the continuous homogeneous internal structure. But actually, they have a wide variety of cross-sectional shapes, and section shape changing along the length, heterogeneous internal structure, with the porosity form. According to the source of the fibers, they can be divided into natural fibers and chemical fibers. Fibers such as cotton, hemp, silk, and wool are the natural fibers with the longest history.

Electromagnetic Function Textiles DOI: http://dx.doi.org/10.5772/intechopen.85586
