Fiberglass, (
also calledAmerican and British English spelling differences are one aspect of American and British English differences.- Historical origins :In the early 18th century, English spelling was not standardized. Differences became noticeable after the publishing of influential dictionaries...
fibreglass and
glass fibre), is material made from extremely fine
fiberFiber, also spelled fibre, is a class of materials that are continuous filaments or are in discrete elongated pieces, similar to lengths of thread. They are very important in the biology of both plants and animals, for holding tissues together. Human uses for fibers are diverse...
s of
glassIn general Glass refers to a solid, brittle, transparent material, commonly used for windows, bottles, or eyewear. Examples of glassy materials include, but are not limited to, soda-lime glass, borosilicate glass, acrylic glass, sugar glass, Muscovy-glass, or aluminium oxynitride. The term glass...
. It is used as a reinforcing agent for many
polymerA polymer is a large molecule composed of repeating structural units typically connected by covalent chemical bonds. While polymer in popular usage suggests plastic, the term actually refers to a large class of natural and synthetic materials with a variety of properties.Due to the extraordinary...
products; the resulting
composite materialComposite materials are engineered materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct on a macroscopic level within the finished structure.- History :The most primitive composite materials were straw...
, properly known as fiber-reinforced polymer (FRP) or
glass-reinforced plasticGlass-reinforced plastic is a material or fiber-reinforced plastic made of a plastic reinforced by fine fibers made of glass. Like carbon fiber reinforced plastic, the composited material is commonly referred to by the name of its reinforcing fibers...
(GRP), is called "fiberglass" in popular usage. Glassmakers throughout history have experimented with glass fibers, but mass manufacture of fiberglass was only made possible with the invention of finer machine tooling. In 1893,
Edward Drummond LibbeyEdward Drummond Libbey is the father of the glass industry in Toledo, Ohio, where he opened the Libbey Glass Company in 1888.-Biography:Libbey was born in Chelsea, Massachusetts, USA...
exhibited a
dressA dress is a garment consisting of a skirt with an attached bodice or with a matching bodice giving the effect of a one-piece garment.Dress may also refer to:*Clothing in general*Costume, fancy dress...
at the
World's Columbian ExpositionThe World's Columbian Exposition — also known as The Chicago World's Fair — was a World's Fair held in Chicago in 1893 to celebrate the 400th anniversary of Christopher Columbus's arrival in the New World. Chicago bested New York City, Washington, D.C. and St. Louis, Missouri, for the honor of...
incorporating glass fibers with the
diameterIn geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
and texture of
silkSilk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from cocoons made by the larvae of the mulberry silkworm Bombyx mori reared in captivity...
fibers. This was first worn by the popular stage actress of the time
Georgia CayvanGeorgia Cayvan or Georgie Eva Cayvan was a popular stage actress in the United States in the later part of the nineteenth century.-Early life:...
.
What is commonly known as "fiberglass" today, however, was invented in 1938 by
Russell Games SlayterGames Slayter was a prolific U.S. inventor best known for developing Fiberglass.Born Russell Games Slayter in Argos, Indiana , he married Maude Marie Foor in 1917. Graduated Argos High School in 1914 and from Western Military Academy in Alton, Illinois, in 1915...
of Owens-Corning as a material to be used as
insulationBuilding insulation refers broadly to any object in a building used as insulation for any purpose. While the majority of insulation in buildings is for thermal purposes, the term also applies to acoustic insulation, fire insulation, and impact insulation...
. It is marketed under the trade name
Fiberglas, which has become a
genericized trademarkA genericized trademark is a trademark or brand name that has become the colloquial or generic description for a general class of product or service, rather than the specific meaning intended by the trademark's holder...
. A somewhat similar, but more expensive technology used for applications requiring very high strength and low weight is the use of
carbon fiberCarbon fiber is a material consisting of extremely thin fibers about 0.005–0.010 mm in diameter and composed mostly of carbon atoms. The carbon atoms are bonded together in microscopic crystals that are more or less aligned parallel to the long axis of the fiber...
.
Fiber formation
Glass fiber is formed when thin strands of silica-based or other formulation glass is
extrudedExtrusion is a process used to create objects of a fixed cross-sectional profile. A material is pushed or drawn through a die of the desired cross-section...
into many fibers with small diameters suitable for
textileA textile is a flexible material consisting of a network of natural or artificial fibres often referred to as thread or yarn. Yarn is produced by spinning raw wool fibres, linen, cotton, or other material on a spinning wheel to produce long strands...
processing. The technique of heating and drawing glass into fine fibers has been known for millennia; however, the use of these fibers for textile applications is more recent. Until this time all fiberglass had been manufactured as
stapleStaple is a term referring to naturally formed clusters or locks of wool fibres throughout a fleece that are held together by cross fibres. The staple strength of wool is one of the major determining factors when spinning yarn as well as the sale price of greasy wool.Virtually all fleece and...
(a term used to describe naturally formed clusters or locks of wool fibres). The first commercial production of fiberglass was in 1936. In 1938 Owens-Illinois Glass Company and Corning Glass Works joined to form the Owens-Corning Fiberglas Corporation. When the two companies joined to produce and promote fiberglass, they introduced continuous filament glass fibers. Owens-Corning is still the major fiberglass producer in the market today.
The types of fiberglass most commonly used are mainly E-glass (alumino-borosilicate glass with less than 1 wt% alkali oxides, mainly used for glass-reinforced plastics), but also A-glass (alkali-lime glass with little or no boron oxide), E-CR-glass (alumino-lime silicate with less than 1 wt% alkali oxides, has high acid resistance), C-glass (alkali-lime glass with high boron oxide content, used for example for glass staple fibers), D-glass (borosilicate glass with high dielectric constant), R-glass (alumino silicate glass without MgO and CaO with high mechanical requirements), and S-glass (alumino silicate glass without CaO but with high MgO content with high tensile strength).
Chemistry
The basis of
textileA textile is a flexible material consisting of a network of natural or artificial fibres often referred to as thread or yarn. Yarn is produced by spinning raw wool fibres, linen, cotton, or other material on a spinning wheel to produce long strands...
-grade glass fibers is silica, SiO
2. In its pure form it exists as a
polymerA polymer is a large molecule composed of repeating structural units typically connected by covalent chemical bonds. While polymer in popular usage suggests plastic, the term actually refers to a large class of natural and synthetic materials with a variety of properties.Due to the extraordinary...
, (SiO
2)
n. It has no true
melting pointThe melting point of a solid is the temperature range at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. When considered as the temperature of the reverse change from liquid to solid, it is referred to as the freezing point...
but softens at , where it starts to
degradeChemical decomposition or analysis is the separation of a chemical compound into elements or smaller compounds. It is sometimes defined as the opposite of a chemical synthesis. Chemical decomposition is often an undesired chemical reaction...
. At , most of the molecules can move about freely. If the glass is then cooled quickly, they will be unable to form an ordered structure. In the polymer, it forms SiO
4 groups which are configured as a tetrahedron with the
siliconSilicon is the most common metalloid. It is a chemical element, which has the symbol Si and atomic number 14. A tetravalent metalloid, silicon is less reactive than its chemical analog carbon...
atom at the center and four oxygen atoms at the corners. These atoms then form a network bonded at the corners by sharing the
oxygenOxygen Oxygen Oxygen (acid, literally "sharp", from the taste of acids) and -γενής (-genēs) (producer, literally begetter) is the element with atomic number 8 and represented by the symbol O...
atoms.
The
vitreousIn general Glass refers to a solid, brittle, transparent material, commonly used for windows, bottles, or eyewear. Examples of glassy materials include, but are not limited to, soda-lime glass, borosilicate glass, acrylic glass, sugar glass, Muscovy-glass, or aluminium oxynitride. The term glass...
and
crystalA crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is crystallography...
line states of silica (glass and
quartzQuartz is the second most abundant mineral in the Earth's continental crust . It is made up of a continuous framework of SiO
4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO
2.There are many different varieties of...
) have similar energy levels on a molecular basis, also implying that the glassy form is extremely stable. In order to induce
crystallizationCrystallization is the process of formation of solid crystals precipitating from a solution, melt or more rarely deposited directly from a gas...
, it must be heated to temperatures above for long periods of time.
Although pure silica is a perfectly viable glass and glass fiber, it must be worked with at very high temperatures, which is a drawback unless its specific chemical properties are needed. It is usual to introduce impurities into the glass in the form of other materials to lower its working temperature. These materials also impart various other properties to the glass which may be beneficial in different applications. The first type of glass used for fiber was
soda limeSoda lime is a mixture of chemicals, used in granular form in closed breathing environments, such as general anaesthesia, submarines, rebreathers and recompression chambers, to remove carbon dioxide from breathing gases to prevent CO2 retention and carbon dioxide poisoning.It is made by...
glass or A glass. It was not very resistant to alkali. A new type, E-glass, was formed; this is an alumino-borosilicate glass that is
alkaliIn chemistry, an alkali is a basic, ionic salt of an alkali metal or alkaline earth metal element. Alkalis are best known for being bases that dissolve in water. Bases are compounds with a pH greater than 7. The adjective alkaline is commonly used in English as a synonym for base, especially for...
free (<2%). This was the first glass formulation used for continuous filament formation. E-glass still makes up most of the fiberglass production in the world. Its particular components may differ slightly in percentage, but must fall within a specific range. The letter E is used because it was originally for electrical applications. S-glass is a high-strength formulation for use when
tensile strengthTensile strength is indicated by the maxima of a stress-strain curve and, in general, indicates when necking will occur. As it is an intensive property, its value does not depend on the size of the test specimen...
is the most important property. C-glass was developed to resist attack from chemicals, mostly
acidAn acid is traditionally considered any chemical compound that, when dissolved in water, gives a solution with a hydrogen ion activity greater than in pure water, i.e. a pH less than 7.0...
s which destroy E-glass. T-glass is a North American variant of C-glass. A-glass is an industry term for cullet glass, often bottles, made into fiber. AR-glass is alkali-resistant glass. Most glass fibers have limited
solubilitySolubility is the property of a solid, liquid, or gaseous chemical substance called solute to dissolve in a liquid solvent to form a homogeneous solution. The solubility of a substance strongly depends on the used solvent as well as on temperature and pressure...
in water but are very dependent on
pHpH is a measure of the acidity or basicity of a solution. It is defined as the cologarithm of the activity of dissolved hydrogen ions . Hydrogen ion activity coefficients cannot be measured experimentally, so they are based on theoretical calculations...
.
ChlorideThe chloride ion is formed when the element chlorine picks up one electron to form an anion Cl
−...
ions will also attack and dissolve E-glass surfaces.
Since E-glass does not really melt, but soften, the softening point is defined as "the temperature at which a 0.55–0.77 mm diameter fiber 235 mm long, elongates under its own weight at 1 mm/min when suspended vertically and heated at the rate of 5°C per minute". The strain point is reached when the glass has a viscosity of 10
14.5 poiseThe poise is the unit of dynamic viscosity in the centimetre gram second system of units. It is named after Jean Louis Marie Poiseuille.The analogous unit in the International System of Units is the pascal second :...
. The
annealingAnnealing is a process of slowly cooling glass to relieve internal stresses after it was formed. The process may be carried out in a temperature-controlled kiln known as a Lehr. Glass which has not been annealed is liable to crack or shatter when subjected to a relatively small temperature change...
point, which is the temperature where the internal stresses are reduced to an acceptable commercial limit in 15 minutes, is marked by a viscosity of 10
13 poise.
Properties
Glass fibers are useful because of their high ratio of surface area to weight. However, the increased surface area makes them much more susceptible to chemical attack. By trapping air within them, blocks of glass fiber make good
thermal insulationThe term thermal insulation can refer to materials used to reduce the rate of heat transfer, or the methods and processes used to reduce heat transfer....
, with a
thermal conductivityIn physics, thermal conductivity, , is the property of a material that indicates its ability to conduct heat. It appears primarily in Fourier's Law for heat conduction.-Measurement:...
of the order of 0.05
WThe watt is a derived unit of power in the International System of Units . It measures rate of energy conversion. One watt is equivalent to 1 joule of energy per second....
/(
mThe metre or meter is the basic unit of length in the International System of Units . Historically, the metre was defined by the French Academy of Sciences as the length between two marks on a platinum-iridium bar, which was designed to represent one ten-millionth of the distance from the Equator...
·
KThe kelvin is a unit increment of temperature and is one of the seven SI base units. The Kelvin scale is a thermodynamic temperature scale where absolute zero, the theoretical absence of all thermal energy, is zero kelvin...
).
The strength of glass is usually tested and reported for "virgin" or pristine fibers—those which have just been manufactured. The freshest, thinnest fibers are the strongest because the thinner fibers are more ductile. The more the surface is scratched, the less the resulting tenacity. Because glass has an amorphous structure, its properties are the same along the fiber and across the fiber.
HumidityHumidity is the amount of water vapour in the air. In daily language the term "humidity" is normally taken to mean relative humidity. Relative humidity is defined as the ratio of the partial pressure of water vapour in a parcel of air to the saturated vapour pressure of water vapour at a prescribed...
is an important factor in the tensile strength. Moisture is easily
adsorbedAdsorption is the accumulation of atoms or molecules on the surface of a material. This process creates a film of the adsorbate on the adsorbent's surface. It is different from absorption, in which a substance diffuses into a liquid or solid to form a solution...
, and can worsen microscopic cracks and surface defects, and lessen tenacity.
In contrast to
carbon fiberCarbon fiber is a material consisting of extremely thin fibers about 0.005–0.010 mm in diameter and composed mostly of carbon atoms. The carbon atoms are bonded together in microscopic crystals that are more or less aligned parallel to the long axis of the fiber...
, glass can undergo more elongation before it breaks. There is a correlation between bending diameter of the filament and the filament diameter. The viscosity of the molten glass is very important for manufacturing success. During drawing (pulling of the glass to reduce fiber circumference), the viscosity should be relatively low. If it is too high, the fiber will break during drawing. However, if it is too low, the glass will form droplets rather than drawing out into fiber.
Glass-reinforced plastic
Glass-reinforced plastic (GRP) is a
composite materialComposite materials are engineered materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct on a macroscopic level within the finished structure.- History :The most primitive composite materials were straw...
or fiber-reinforced plastic made of a
plasticPlastic is the general common term for a wide range of synthetic or semisynthetic organic amorphous solid materials suitable for the manufacture of industrial products...
reinforced by fine glass fibers. Like graphite-reinforced plastic, the composite material is commonly referred to by the name of its reinforcing fibers (fiberglass).
Thermosetting plasticThermosetting plastics are polymer materials that irreversibly cure. The cure may be done through heat , through a chemical reaction , or irradiation such as electron beam processing.Thermoset materials are usually liquid or malleable prior to curing and designed to be molded into their final...
s are normally used for GRP production—most often unsaturated polyester (using 2-butanone peroxide aka MEK peroxide as a catalyst), but
vinylesterVinyl Ester, or Vinylester, is a resin produced by the esterification of an epoxy resin with an unsaturated monocarboxylic acid. The reaction product is then dissolved in a reactive solvent, such as styrene, to a 35 - 45 percent content by weight....
or
epoxyEpoxy or polyepoxide is a thermosetting polymer formed from reaction of an epoxide "resin" with polyamine "hardener". Epoxy has a wide range of applications, including fiber-reinforced plastic materials and general purpose adhesives.- Chemistry :...
are also used. Traditionally, styrene monomer was used as a reactive diluent in the resin formulation giving the resin a characteristic odor. More recently alternatives have been developed. The glass can be in the form of a chopped strand mat (CSM) or a woven fabric.
As with many other composite materials (such as
reinforced concreteReinforced concrete is concrete in which steel reinforcement bars , plates or fibers have been incorporated to strengthen a material that would otherwise be brittle.-History:...
), the two materials act together, each overcoming the deficits of the other. Whereas the plastic resins are strong in
compressivePhysical compression is the result of the subjection of a material to compressive stress, resulting in reduction of volume. The opposite of compression is rarefraction tension.- Explanation :...
loading and relatively weak in
tensile strengthTensile strength is indicated by the maxima of a stress-strain curve and, in general, indicates when necking will occur. As it is an intensive property, its value does not depend on the size of the test specimen...
, the glass fibers are very strong in tension but have no strength against compression. By combining the two materials, GRP becomes a material that resists both compressive and tensile forces well. The two materials may be used uniformly or the glass may be specifically placed in those portions of the structure that will experience tensile loads.
Uses
Uses for regular fiberglass include mats,
thermal insulationThe term thermal insulation can refer to materials used to reduce the rate of heat transfer, or the methods and processes used to reduce heat transfer....
,
electrical insulationAn insulator, also called a dielectric, is a material that resists the flow of electric current. An insulating material has atoms with tightly bonded valence electrons. These materials are used in parts of electrical equipment, also called insulators or insulation, intended to support or separate...
, reinforcement of various materials, tent poles, sound absorption, heat- and corrosion-resistant fabrics, high-strength fabrics, pole vault poles, arrows, bows and crossbows, translucent roofing panels, automobile bodies, hockey sticks,
surfboardA surfboard is an elongated platform used in the sport of surfing. They are relatively light, but strong enough to support an individual standing on them while riding a breaking wave. They were invented in Hawaii, where they were known as Papa he‘e nalu in the Hawaiian language, usually made of...
s and boat hulls. It has been used for medical purposes in casts. Fiberglass is extensively used for making
FRP tanks and vesselsFRP is a modern composite material of construction for chemical plant equipment like tanks and vessels...
. Fiberglass is also used in the design of
Irish stepdanceIrish stepdance is a type of performance dance originating in Ireland from traditional Irish dance. Irish stepdancing has been recently popularized by the world-famous show "Riverdance" and its followers. Irish stepdance is performed in most places with large Irish populations, though most...
shoes.
Role of recycling in fiberglass manufacturing
Manufacturers of fiberglass insulation can use recycled glass.
Owens CorningOwens Corning Corporation is the world's largest manufacturer of fiberglass and related products. It was formed in 1935 as a partnership between two major American glassworks, Corning Glass Works and Owens-Illinois. The company was spun off as a separate entity on November 1, 1938...
's fiberglass has 40% recycled glass. A recycling program begun in 2009 in
Kansas City, KansasKansas City is the third largest city in the U.S. state of Kansas and is the county seat of Wyandotte County. It is a satellite city of Kansas City, Missouri and is the third largest city in the Kansas City Metropolitan Area. The city is part of the "Unified Government" which also includes the...
, will ship crushed recycled glass, called cullet, to the Owens Corning plant that will use it as raw material for fiberglass making.
See also
- Glass microsphere
Glass microspheres are microscopic spheres of glass manufactured for wide a variety of uses in research, medicine, consumer goods and various industries. Glass microspheres are usually between 1 to 1000 micrometers in diameter. The term is also used for glass spheres between 100 nanometers to 5...
- Building insulation
Building insulation refers broadly to any object in a building used as insulation for any purpose. While the majority of insulation in buildings is for thermal purposes, the term also applies to acoustic insulation, fire insulation, and impact insulation...
- Fiberglass molding
Fiberglass molding is a process in which fiberglass reinforced resin plastics are formed into useful shapes.-Mold Making:The fiberglass mold process begins with an object known as the plug or buck. This is an exact representation of the object to be made, and can be made from a variety of different...
- Composite materials
- Physics of glass
The physics of glass is the science of the glassy or amorphous state of matter as seen from an atomic or molecular point of view. This article provides an overview of research into glass: a solid in which no significant crystallization has occurred...
- Glass transition
Glass transition or vitrification refer to the transformation of a glass-forming liquid into a glass, which usually occurs upon rapid cooling. It is a dynamic phenomenon occurring between two distinct states of matter , each with different physical properties...
- Strength of glass
Fibers constitute a major component of the glass industry. The traditional fiberglass companies manufacture either reinforcement fibers or fibers for thermal and acoustic insulations. During the last three or four decades, a new glass fiber industry, namely the fiber optics industry, has seen...
- Filament tape
Filament tape or strapping tape is a pressure sensitive tape used for several packaging functions such as closing corrugated fiberboard boxes, reinforcing packages, bundling items, pallet unitizing, etc...
- Optical fiber
An optical fiber is a glass or plastic fiber that carries light along its length. Fiber optics is the overlap of applied science and engineering concerned with the design and application of optical fibers...
- Basalt fiber
Basalt fiber or fibre is a material made from extremely fine fibers of basalt, which is composed of the minerals plagioclase, pyroxene, and olivine. It is similar to carbon fiber and fiberglass, having better physicomechanical properties than fiberglass, but being significantly cheaper than...
- Carbon fiber
Carbon fiber is a material consisting of extremely thin fibers about 0.005–0.010 mm in diameter and composed mostly of carbon atoms. The carbon atoms are bonded together in microscopic crystals that are more or less aligned parallel to the long axis of the fiber...
- Glass wool
Glass wool is an insulating material, made from fiber glass, arranged into a texture similar to wool. Glass wool is produced in rolls or in slabs, with different thermal and mechanical properties.-Manufacturing process:...
- Gelcoat
A gelcoat is a material used to provide a high quality finish on the visible surface of a fibre-reinforced composite material. The most common gelcoats are based on epoxy or unsaturated polyester resin chemistry. Gelcoats are modified resins which are applied to moulds in the liquid state...
- BS4994
BS4994 is the "specification for the design and construction of vessels and storage tanks in reinforced plastics"...
External links