Glass - A Versatile Material With Many Uses

Glass - A Versatile Material With Many Uses

Glass is a versatile material that has been used since ancient times in both utilitarian and decorative applications.glass c While melting glass and drawing it into fibers is a long-established technique, the first continuous glass fiber was produced in the 1930’s by Owens-Corning as glass wool and given the popular name fiberglass.glass c This type of fiber is the most widespread among all reinforcements and is available in a wide variety of compositions. The principal component is silica, SiO2, and the various impurities in combination with it give different types of glass their specific properties.

Pure silica has a high melting point, making it difficult to work with, so it is often combined with other materials to reduce its temperature and add desired properties.glass c For example, soda lime glass (A-glass) is a common form of commercial fiberglass that offers good mechanical properties and water durability, while E-glass was originally developed for electrical insulation but also provides high strength, stiffness, and softening point.glass c Another common type is borosilicate, or B-glass, which has high acid resistance, and corrosion resistant, or CR-glass, which is a specialized variant for use in battery plate separators.

The main advantage of fiberglass is its excellent strength-to-weight ratio.glass c This quality makes it suitable for many applications where other materials are impractical or inefficient, including abrasion resistance, fire resistance, and thermal insulation.glass c It is also easy to process, providing a great deal of flexibility in design and manufacturing.

For example, glass fibers can be twisted, cut, or punched into different shapes and sizes to meet specific needs.glass c It is also very compatible with a wide range of polymers, which allows it to be used in many kinds of composites.glass c This versatility is one reason why there is such a tremendous growth in the use of fiberglass in modern automobiles, which are increasingly being made with lightweight composite materials.

Glass fibers are made by drawing molten glass through electric-heated platinum bushings.glass c The most important raw material in this process is sand, which contains silica.glass c This is mixed with a variety of other minerals to reduce the melting point and add desirable chemical properties. For instance, soda lime glass (A-glass) contains about 6 percent limestone, 4 percent magnesia, and 2 percent alumina; and borosilicate glass contains cerium oxide and zinc oxide.

The result is a continuous fiber that has the strength of bulk glass but with a much lower specific gravity, which is beneficial in many applications.glass c The atomic structure of glass is amorphous, with ionic bonds linking the silicon atoms at the corners of a tetrahedron. This gives it a very low elastic modulus, so it is relatively inexpensive and requires fewer specialized machines to handle than most other materials of comparable moduli.

Working with glass c fibers can be hazardous because it can release airborne silica dust particles.glass c Consequently, special safety equipment, such as respirators, is recommended for those who work with it. In addition, it is necessary to take measures to keep the workplace clean, as this will significantly reduce exposure and the associated health hazards.

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