Glass Fibers and their Applications

Noah Martin, Lucas Mason, Chris Johnson, Chris Harmon, and Hayden Greer

What Are Glass Fibers?

• Glass fibers are microscopic strands of glass which are generally used as a reinforcing agent for various materials
• While they are commonly known as fiberglass, which specifically refers to a fiber reinforced sheet of glass, their applications are much more vast than just a stronger alternative to glass

A Bit of History

• Glass fibers can be traced back to circa 1870, but it wasn’t until the mid 1930s that they gained appreciation for their properties and applications
• In 1893 Edward drummond Libbey produced a dress and presented it at the world's columbian exposition. The glass fibers in the dress had the same texture and diameter as silk, but this material wasn't the same as the modern day glass fibers.
• In 1938 the Owens-Illinois Glass Company and Corning Glass Works merged to make the Owens-Corning Fiberglas Corporation.

Material Properties

Material Structure

• There are many different variations of glass fibers which are generally categorized by their application.
• All Glass Fibers are primarily made of Silica (SiO2) which makes up over 50% of their composition by weight, and the rest is made up from a variety of compounds which vary with the grade of fiber
• Glass fibers have very little crystalline structure unlike most polymers

Mechanical Properties

• Fiberglass tends to have a much greater strength to density ratio than competing materials
• Very high strengths ranging from 3300 to 4600 MPa
• Modulus of elasticity ranges 55 to 89 GPa

Thermal Properties

• Glass Fibers are mainly used as thermal insulators because of their high ratio of surface area to weight.
• The thermal conductivity of glass fiber textiles can reach 0.05 W/mK
• Essentially tiny cells will result in a low-density textile product that will turn and produce thermal insulation.

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Electrical Properties

• Glass fibers have outstanding electrical properties. First of all, they can withstand a high temperature and have a low moisture regain.
• Glass has a low dielectric constant high dielectric strength.
• Electrical Properties of glass fibers tend to be determined by their volume resistivity, surface conductivity, and dielectric constant.

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Imperfections

• A few imperfections of glass fibers would have to include warpage (which can lead to deterioration) and low weld
• Knit line strength, higher viscosity of melt, and low surface quality are a few other imperfections.
• Glass fibers are also known for damaging machines due to their abrasion when interacting with other machines (which can be costly).

Failure Mechanisms

• Failures for glass fibers occur at the cracks and scratches that are initiated at the surface by an applied tensile strength, most of the time.
• Another failure mechanism occurs when glass fibers are being peeled off due to abrasion.
• Most failure mechanisms found were those that started with void formation at the ends of the fibers and those that had very small cracks around the ends of the fibers.

Processing

• The EPA states that, raw glass fiber material is melted at a high-temperature (ranging from 1500 to 1700 degrees Celsius).
• That raw glass fiber material includes compounds such as Silica (SiO2). This silica is heated to approximately 1700 degrees Celsius and then quickly cooled down turning into a glass fiber.
• Batching, melting, fiberization, and drying/packaging are the 4 essential steps to producing glass fibers.

Manufacturing Process

• Direct Melting
• Raw materials are melted and pulled into fibers using bushing
• It is completed in three steps
• Melting
• Fiberization
• Sizing

Applications

Insulation

Glass fibers are a crucial component in commercial and residential insulation.

• There are two forms of glass fiber insulation
• Flexible blanket
• Rigid boards
• Glass fibers woven together create insulation by trapping pockets of air which keeps rooms warm in the winter and cool in the summer.

Marine Applications:

Glass-fiber-reinforced polyester is commonly used in the construction of various sized boat shells as well as laminate coatings

• Advantages
• The most cost-effective choice
• High tensile strength
• Very resistant to water degradation
• Easy to repair
• Disadvantages
• Susceptible to failure after long period of sustained loads.

Automotive Industry

Glass-fiber-reinforced polymers are highly utilized in mechanical parts and door panels.

• Advantages
• Much lighter than metallic parts making the automobile more fuel efficient.
• Much more cost effective

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Aerospace Innovations

• The aerospace industry is currently transitioning to materials that aim to minimize fuel consumption and fiberglass is a major component to this change.
• Glass-fiber-reinforced composites are used to make various aircraft components:
• Aircraft wings
• Helicopter rotor blades
• Engine ducts
• Another advantage of glass fibers, which pertains to the military, is how they cannot be detected by radar, which can be used for stealth applications

Civil Construction

• Fiberglass reinforced concrete
• Fiberglass mixed with cement is significantly lighter than conventional concrete and provides more protection from environmental damage.
• Fiberglass concrete is being used as a lightweight method of adding detail and support to building exteriors. Its moldable properties allow it to be utilized in almost any building structure while not drastically increasing overall building weight.
• Fiberglass reinforced panels
• Strong, lightweight, scratch resistant, affordable, and easily installed
• These wall and ceiling panels can be easily installed over drywall and provide a simple surface repair.

Electrical Applications:

Due to glass fibers electrical properties, they are highly used in electrical situations as insulators.

• Glass fibers are found in:
• Circuit breakers
• Power cables
• Printed circuit boards
• Thermocouples

Their ability to withstand high temperatures offers flexibility for different magnitudes of insulation situations.

Sources

Barry, Craig. “The Thermal Properties of Glass Fiber Thread.” B&W Fiberglass News, B&W Fiberglass, 30 Jan. 2018, info.bwfiberglass.com/blog/the-thermal-properties-of-glass-fiber-thread.

Buschow, Kurt H. Jürgen. Encyclopedia of Materials: Science and Technology. Elsevier, 2001.

The Editors of Encyclopaedia Britannica. “Fibreglass.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 13 June 2017, www.britannica.com/technology/fiberglass.

EPA Contributors. “Glass Fiber Manufacturing.” EPA, EPA.gov, www3.epa.gov/ttn/chief/ap42/ch11/final/c11s13.pdf.

“Fiberglass.” New World Encyclopedia, New World Encyclopedia, Inc., 7 Apr. 2017, www.newworldencyclopedia.org/entry/Fiberglass.

“Glass Fibers.” Science Direct, 2019, www.sciencedirect.com/topics/physics-and-astronomy/glass-fibers.

Khan, Moin. “Applications of Composite Glass Fiber.” Textile Learner, Textile Learner, 2019, textilelearner.blogspot.com/2012/09/glass-fiber-composites-properties-of.html.

Wallenberger, Frederick, et al. “Glass Fibers.” ASM International, Asminternational.org, 2001, www.asminternational.org/documents/10192/1849770/06781G_p27-34.pdf.

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Any Questions?

Contributions

• Noah Martin
• Project Team Lead
• Research in History, Material Structure, Mechanical Properties, and Application.
• Lucas Mason
• Participated in research of the Applications of Glass Fibers as well as the manufacturing process.
• Chris Harmon
• Research in Applications, Material Structure, and Thermal Properties
• Chris Johnson
• Research in Applications, Production/Manufacturing, Imperfections, Failure, and Properties
• Hayden Greer
• Research in Thermal Properties, Electrical Properties, Imperfections, and Failure

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