*2.3.2. Carbon*

**2.3. Other fibers**

**Table 3.** Glass fiber composition

**•** AE-glass: alkali resistant glass [6].

utilization as a finished product.

Glass fiber is an inorganic nonmetallic man-made fiber. Generally, the glass is defined as the frozen state of a supercooled and thus solidified liquid. It results from the suppression of the crystallization of melt. Initial materials for producing glass are different mineral substances

largely found in nature (quartz sand, chalk, dolomite, feldspar, and others).

Glass fibers are produced from different compositions (%) of glass (Table 3).

Silica (SiO2) 54.0**-**56.0 Alumina (Al2O3) 12.0**-**14.5 Boron anhydride(B2O3) 5.0**-**10.0 Calcium oxide (CaO) 15.5**-**16.5 Magnesium oxide (MgO) 4.0**-**4.2 Sodium oxide (Na2O) 0.7**-**1.0 Iron oxide (Fe2O3) Up to 0.3

Nonwovens of glass fibers are classified as follows:

**•** C-glass: shows better resistance to chemical impact.

and building materials for insulation and so forth [32].

**•** A-glass: close to window glass with regard to its composition.

**•** E-glass: combines the characteristics of C-glass with very good insulation to electricity.

In general, textile glass fibers have a high tenacity at a low elongation combined with extremely low density. This results in favorable tenacity or modulus values relative to their weight. Glass fiber is brittle, but in drawing very thin fibers (with a diameter of several micron) from molten glass, a fibrous material is obtained, having a flexibility sufficient for textile processing and

Glass fiber mats are excellent heat and noise insulation materials. They are capable of with‐ standing temperatures above 150°C. Textile glass as a mineral material is naturally inflamma‐

Glass fabrics are highly efficacious for filtering various liquids; filters of glass fibers used for filtering corrosive chemical reagents have a life 10 or 15 times longer than those made of usual materials (cotton, metal web etc). Glass staple fibers are used for the reinforcement of plastics

ble and does not release steam or poisonous gases when subjected to heat.

*2.3.1. Glass*

14 Non-woven Fabrics

Although first produced for electric lamp filaments from cupro-cellulose by Pauly, Fremery, Bromert and Urban at Oberbruch near Aachen, Germany, in 1898, carbon fibers only gained significance after 1963. In recent years, carbon fibers have found much attention. They are made by means of thermal degradation of viscose fibers or polyacrylonitrile fibers at temper‐ atures up to 1000°C or even 1500°C. The fibers contain between 95 and 98 % carbon. Additional thermal treatment of the pyrolized polyacrylonitrile fibers at temperatures between 2000 and 3000°C converts them into graphite, which shows an excellent grid-like structure, where carbon contents amount to 99% [6].

Among the exceptional properties of carbon fibers are their high tenacity, high modulus of elasticity, high brittleness, low creeping tendency, chemically inert behavior, low heatexpansion, and good electrical conductivity. Using their unique properties, the application of carbon fiber is most pronounced in the superfiber category. The high modulus of carbon fibers makes them best suitable for application in composite materials used in high- performance functions. Carbon fiber is not used on its own, but mixed with resin as fiber reinforced materials. This is called a composite material and is now one of the most important structural and heat-resistant materials. The composite material made of glass fiber and plastic is distin‐ guished as glass fiber-reinforced plastics (G-FRP) from that made of carbon fiber and plastic (carbon fiber-reinforced plastic, C-FRB) [14,33].

Such composites are mainly used in:


In recent years, some new applications of carbon fibers have been found, such as rehabilitation of a bridge in building and construction industry. Others include decoration in automotive, marine, general aviation interiors, general entertainment and musical instruments and after market transportation products. Conductivity in electronics technology provides additional new application [34].
