Glass Fiber and Fiberglass

Glass Fiber and Fiberglass Fiberglass refers to a group of products assembled from individual glass fibers in various forms. Glass fibers can be divided into two main groups according to their geometry: continuous fibers used in yarns and textiles, and discontinuous (short) fibers used as layers, coverings or sheets for insulation and filtration. Glass fiber can be made into yarn like wool or cotton and woven into fabrics. Fiberglass textiles are frequently used as reinforcement material in molded and laminated plastics. Glass fiber wool, a thick, fluffy material made from continuous fiber, is used for thermal insulation and sound absorption. It is generally found in ship and submarine compartments and hulls. It is also frequently used in automobile engine compartments and body panel covers, oven and air-conditioning units, acoustic wall and ceiling panels, and architectural sections. Different types of fiberglass exist: Type E is specialized for electrical insulation tapes, textiles and as a reinforcement element, Type C with superior acid resistance for the chemical field, and Type T is specialized for thermal insulation. Commercial use of glass fiber is relatively recent, but even though not on an industrial scale, we observe different applications throughout history. During the Renaissance, glass wires were used to decorate glasses and vases. French physicist Rene-Antoine Ferchault de Reaumur produced textile products decorated with fine glass threads in 1713, and English inventors repeated this achievement in 1822. An English silk weaver made a glass fabric in 1842, and another inventor, Edward Libbey, introduced a glass woven dress at the 1893 Columbian Exposition in Chicago. This dress was first worn by popular theater actress Georgia Cayvan of the period. Glass wool, consisting of a pile of discontinuous fiber at random lengths, was produced in Europe at the beginning of the century using a process involving drawing fibers horizontally from rods onto a rotating drum. Decades later, a spinning process was developed and patented. Glass fiber insulation material was produced in Germany during World War I. However, true industrial production of glass fibers took place in the United States in the 1930s. Corning Glass, which conducted experiments on glass fiber manufacturing, recognized the potential growth of the glass fiber insulation market and approached Owens-Illinois in 1920, proposing a partnership in glass fiber production. Owens-Illinois accepted this proposal, recognizing the benefits of Corning's knowledge regarding glass formulations, and the companies decided to share the costs of developing glass fiber. Russell Games Slayter, a researcher at Owens-Illinois, discovered mass production of glass fiber in 1932 when he directed a jet of pressurized air onto a molten glass stream. Owens-Illinois helped Corning Glass set up experimental glass wool and other equipment at Corning's facility in New York in 1936. "Fiberglass" was first used in January 1936 as Owens-Illinois's brand for glass fiber products. In 1938, experimental costs resulted in Owens-Illinois and Corning Glass's joint venture continuing as a separate company. In the same year, the glass fiber manufacturing patent, first applied for in 1935, was granted to Dale Kleist and Jack Thomas. On 1 November 1938, the establishment of Owens-Corning Fiberglass® Corporation was announced. Owens-Corning continues to operate today as an important company in the sector.

How Is It Manufactured?

Glass fiber product raw materials are various natural minerals and manufactured chemicals. The main materials are silica sand, limestone and soda ash. Other materials may include calcined alumina, borax, feldspar, nepheline syenite, magnesite and kaolin clay. Silica sand is used as a glass former; soda ash and limestone primarily help reduce melting temperature. Some other materials such as borax are used to improve chemical resistance properties. Waste glass, also called cullet, is also used as a raw material. Raw materials must be carefully weighed in precise amounts and thoroughly mixed before being melted into glass. After the batch is prepared, it is sent to a furnace for melting. The furnace can be heated by electricity, fossil fuel, or a combination of both. Temperature must be precisely controlled to provide a consistent, steady glass flow. Molten glass must be maintained at a higher temperature (approximately 2500°F [1371°C]) than other glass types to be converted into fiber. When glass is in molten state, it is transferred to shaping equipment through a channel (forehearth) at the end of the furnace. Depending on the fiber type, various processes are performed to create fibers. Textile fibers can be obtained directly from the furnace. Alternatively, molten glass can first be directed to a machine that will form glass marbles with a diameter of 0.62 cm (1.6 cm), which allows visual inspection of the glass for impurities. In both direct melting and marble melting processes, glass or glass marbles are directed to electrically heated bushings (also called nose holes). The bushing is made of platinum or metal alloy and contains 200 to 3,000 very fine holes. Molten glass passes through the holes and exits as fine filaments.

Glass Fiber Applications from Past to Present

Glass fiber has mechanical properties roughly comparable to other fibers such as polymers and carbon fiber. Although not as strong or stiff as carbon fiber, when used as a composite it is much cheaper and less brittle. Glass fibers are therefore used as a reinforcing material for many polymer products. Fiber-reinforced polymer (FRP) and glass-reinforced plastic (GRP), also known as fiberglass, which are very strong and relatively lightweight, are the leading of these products. The inclusion of FRP composite technology in the industrial world is not very old. Chemists and industrialists in the early 1900s took important steps to mimic materials from nature in a way that would give them superior properties. Scientists worked on the needs of electronics, defense and ultimately space technology. As a result of this work, it became possible to produce materials with properties that defied known principles, such as Kevlar stopping bullets. The first known FRP product was a boat hull produced in the mid-1930s as part of a manufacturing experiment using fiberglass fabric and polyester resin laid in a foam mold. FRP composite applications revolutionized all industries including aerospace, marine, electrical, corrosion resistance and automotive/transportation. The use of fiber-reinforced polymer (FRP) composite materials, particularly in aerospace and maritime applications in the defense industry, dates back to the early 1940s. The US Air Force and Navy used FRP because it had a high strength-to-weight ratio and was resistant to corrosive effects in air and sea. FRP was focused on as an alternative, also influenced by the difficulties in metal supply during World War II. By 1945, more than 3.5 million kilograms of glass fiber were being shipped, primarily for military applications. The benefits of FRP composites, particularly its corrosion resistance properties, were communicated to the public and received great interest. For example, glass fiber pipe, launched in 1948, found the widest application in the oil industry market due to its superior corrosion properties. FRP composites proved to be a good alternative to other conventional materials even in high-pressure, large-diameter chemical processing situations. In addition to superior corrosion resistance, FRP pipe offered durability and strength, eliminating the need for internal lining, external facing and/or cathodic protection. Since the early 1950s, FRP composites have been widely used and continue to be used in equipment for chemical processing, pulp and paper, energy, waste treatment, metal refining and other manufacturing industries. In addition to chemicals or gasoline underground tanks, FRP helps field-proven performance in many products and chemical facilities such as gas scrubbers, tanks, hoods, ducts, fans, stacks, pipes, pumps and pump bases, valve bodies and above-ground floors. The years after the 1940s brought new and often revolutionary applications for FRP composites. Technology that produced reinforced plastic rings required for the Manhattan nuclear project during World War II enabled the development of high-performance composite materials for solid rocket motor cases and tanks in the 1960s and 1970s. Fiberglass wall tanks were used in space under the Skylab project to provide oxygen to astronauts on duty in earth orbit. Moving to different applications, we see the Chevrolet Corvette with fiberglass body panels roll off the assembly line in 1953. In this context, high-performance racing cars and passenger vehicles continue to provide a foundation in terms of technology transfer today. In the 1960s, the British and US navies were simultaneously developing minesweepers because FRP composites had superior properties compared to other materials in the harsh marine environment, and additionally they were non-magnetic, which was a very important advantage. In this way, it was discovered that FRP had the ability to reduce the radar signature of a structure like a ship or aircraft. High-performance composite materials demonstrated their superiority in advanced technology aircraft such as the F-117 Stealth Fighter and B-2 Bomber. Currently, FRP composites are used for space applications and are being tested in many different NASA projects.

Aerospace

The airline industry is transitioning to aircraft and technologies that are energy-efficient and more environmentally friendly, and in this sense fiberglass provides an ideal solution. The strength-to-weight ratio, impact and corrosion resistance, and the non-flammable properties of fiberglass have extremely positive effects in the aerospace industry in the reinforcement of aircraft laminates, luggage boxes and other composite structures. While lighter composites are used in newer commercial aircraft such as the Airbus A380 and Boeing 787 Dreamliner, the conventional materials of older aircraft are also being replaced with lightweight fiberglass composites.

Applications:

Luggage boxes, interior panels and flooring, structural parts, fuel tanks, helicopter blades, cargo port handling.

Construction

Building construction and job sites are filled with fiberglass products. The lightness of glass fiber facilitates the carrying of equipment such as ladders, shovels and tool handles. Corrosion-resistant properties make glass fiber an ideal material for bathtubs and shower cabins. Because it is fire-resistant, it is used in wall panels, drywall and roof coverings. Fiberglass offers an attractive and environmentally friendly alternative to wood, steel and aluminum in many different ways.

Applications:

Windows and railings, drywall, bathtubs and showers, roof covering zone, insect and sun screens, wall coverings.

Consumer Products

When we look around us, we see that many products used daily are fiberglass and fiberglass-reinforced plastic. Due to its flexibility and lightness, fiberglass is frequently used in the production of sports equipment, reinforced boats, jet skis and swimming pools. Fiberglass is also used successfully in many different ways in DIY (do-it-yourself) projects.       Prepared by: B. Serhat Cengiz