Fiberglass (also called fibreglass and glass fibre) is material made from extremely fine fibers of glass. Fiber or fibre is a class of Materials that are continuous filaments or are in discrete elongated pieces similar to lengths of thread. Glass in the common sense refers to a Hard, Brittle, transparent Solid, such as that used for Windows many It is used as a reinforcing agent for many polymer products; the resulting composite material, properly known as fiber-reinforced polymer (FRP) or glass-reinforced plastic (GRP), is called "fiberglass" in popular usage. A polymer is a large Molecule ( Macromolecule) composed of repeating Structural units typically connected by Covalent Chemical bonds Composite materials (or composites for short are engineered Materials made from two or more constituent materials with significantly different physical or chemical A fibre-reinforced plastic ( FRP) (also fibre-reinforced polymer) is a Composite material comprising a Polymer matrix reinforced with fibres Glass-reinforced plastic ( GRP) is a Composite material or Fiber-reinforced plastic made of a Plastic reinforced by fine fibers
Glassmakers throughout history have experimented with glass fibers, but mass manufacture of fiberglass was only made possible with the advent of finer machine-tooling. In 1893, Edward Drummond Libbey exhibited a dress at the World's Columbian Exposition incorporating glass fibers with the diameter and texture of silk fibers. Edward Drummond Libbey (1854-1925 is the father of the glass industry in Toledo Ohio, where he opened the Libbey Glass Company in 1888 A dress (also frock, gown) is a garment consisting of a Skirt with an attached Bodice or with a matching bodice giving the effect of a one-piece The World's Columbian Exposition (also called The Chicago World's Fair) a World's Fair, was held in Chicago in 1893 to celebrate the 400th anniversary 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 Silk is a natural Protein Fiber, some forms of which can be woven into Textiles The best-known type of silk is obtained from cocoons What is commonly known as "fiberglass" today, however, was invented in 1938 by Russell Games Slayter of Owens-Corning as a material to be used as insulation. Games Slayter ( December 9 1896 &ndash October 15 1964) was a prolific U Owens Corning Corporation ( is the world's largest manufacturer of Fiberglass and related products It is marketed under the trade name Fiberglas, which has become a genericized trademark. A genericized trademark (also known as a generic trademark or proprietary eponym) is a Trademark or Brand name that has become the colloquial
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Formation
Glass fiber is formed when thin strands of silica-based or other formulation glass is extruded into many fibers with small diameters suitable for textile processing. The Chemical compound silicon dioxide, also known as silica or silox (from the Latin " Silex " is an Oxide Extrusion is a process used to create objects of a fixed cross-sectional profile A textile is a flexible material comprised of a network of natural or artificial Fibres often referred to as thread or Yarn. Glass, even as a fiber, has little crystalline structure (see amorphous solid). An amorphous solid is a Solid in which there is no Long-range order of the positions of the Atoms (Solids in which there is long-range atomic order are The properties of the structure of glass in its softened stage are very much like its properties when spun into fiber. One definition of glass is "an inorganic substance in a condition which is continuous with, and analogous to the liquid state of that substance, but which, as a result of a reversible change in viscosity during cooling, has attained so high a degree of viscosity as to be for all practical purposes rigid. Traditionally inorganic compounds are considered to be of mineral not biological origin Liquid is one of the principal States of matter. A liquid is a Fluid that has the particles loose and can freely form a distinct surface at the boundaries of Viscosity is a measure of the resistance of a Fluid which is being deformed by either Shear stress or Extensional stress. "[1]
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. 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. Owens-Illinois ( is a Fortune 1000 company that specializes in Glass containers Corning Incorporated ( is an American manufacturer of Glass, Ceramics and related materials primarily for industrial and scientific applications Owens Corning Corporation ( is the world's largest manufacturer of Fiberglass and related products Until this time all fiberglass had been manufactured as staple. Staple is a term referring to naturally formed clusters or locks of Wool fibres throughout a fleece that are held together by cross fibres When the two companies joined together to produce and promote fiberglass, they introduced continuous filament glass fibers. Staple is a term referring to naturally formed clusters or locks of Wool fibres throughout a fleece that are held together by cross fibres [1] Owens-Corning is still the major fiberglass producer in the market today.
Chemistry
The basis of textile grade glass fibers is silica, SiO2. A textile is a flexible material comprised of a network of natural or artificial Fibres often referred to as thread or Yarn. The Chemical compound silicon dioxide, also known as silica or silox (from the Latin " Silex " is an Oxide In its pure form it exists as a polymer, (SiO2)n. A polymer is a large Molecule ( Macromolecule) composed of repeating Structural units typically connected by Covalent Chemical bonds It has no true melting point but softens up to 2000°C, where it starts to degrade. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. At 1713°C, most of the molecules can move about freely. In Chemistry, a molecule is defined as a sufficiently stable electrically neutral group of at least two Atoms in a definite arrangement held together by If the glass is then cooled quickly, they will be unable to form an ordered structure. [2] In the polymer it forms SiO4 groups which are configured as a tetrahedron with the silicon atom at the center, and four oxygen atoms at the corners. Silicon (ˈsɪlɪkən or /ˈsɪlɪkɒn/ silicium is the Chemical element that has the symbol Si and Atomic number 14 These atoms then form a network bonded at the corners by sharing the oxygen atoms. Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the
The vitreous and crystalline states of silica (glass and quartz) have similar energy levels on a molecular basis, also implying that the glassy form is extremely stable. Vitreous refers to a material in an Amorphous, Glassy state (in contrast to a Crystalline state In Materials science, a crystal is a Solid in which the constituent Atoms Molecules or Ions are packed in a regularly ordered repeating Quartz (from German) is the most abundant Mineral in the Earth 's Continental crust (although Feldspar is more common in In order to induce crystallization, it must be heated to temperatures above 1200°C for long periods of time. Crystallization is the (natural or artificial process of formation of solid Crystals precipitating from a homogeneous --> identical Solution [1]
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 lime glass or A glass. Soda lime is a mixture of Chemicals used in granular form in closed breathing environments such as General anaesthesia, Submarines Rebreathers It was not very resistant to alkali. A new type, E-glass was formed that is alkali free (< 2%) and is an alumino-borosilicate glass. In Chemistry, an alkali (from Arabic: Al-Qaly القلي القالي) is a basic, ionic salt of an Alkali metal [3] 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 strength is the most important property. Tensile strength \sigma_{UTS} or S_U is the Stress at which a material breaks or permanently deforms C-glass was developed to resist attack from chemicals, mostly acids which destroy E-glass. In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are [3] T-glass is a North American variant of C-glass. A-glass is an industry term for cullet glass, often bottles, made into fiber. Glass recycling is the process of turning Waste Glass into usable products AR-glass is alkali resistant glass. Most glass fibers have limited solubility in water but it is very dependent on pH. Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. pH is the measure of the acidity or alkalinity of a Solution. Chloride ions will also attack and dissolve E-glass surfaces. The chloride Ion is formed when the element Chlorine picks up one Electron to form an Anion (negatively-charged ion Cl&minus A recent trend in the industry is to reduce or eliminate the boron content in the glass fibers. Boron (ˈbɔərɒn is a Chemical element with Atomic number 5 and the chemical symbol B.
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". [4] The strain point is reached when the glass has a viscosity of 1014. 5 poise. The annealing 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 1013 poise. Annealing is a process of slowly cooling Glass to relieve internal stresses after it was formed [4]
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 insulation, with a thermal conductivity of 0. The 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 In Physics, thermal conductivity, k is the property of a material that indicates its ability to conduct Heat. 05 W/m-K.
Glass strengths are usually tested and reported for "virgin" 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. [3] Because glass has an amorphous structure, its properties are the same along the fiber and across the fiber. An amorphous solid is a Solid in which there is no Long-range order of the positions of the Atoms (Solids in which there is long-range atomic order are [2] Humidity is an important factor in the tensile strength. Humidity is the amount of water vapor in the air In daily language the term "humidity" is normally taken to mean Relative humidity. Moisture is easily adsorbed, and can worsen microscopic cracks and surface defects, and lessen tenacity. Adsorption is a process that occurs when a gas or liquid Solute accumulates on the surface of a solid or a liquid (adsorbent forming a film of molecules or atoms (the
In contrast to carbon fiber, glass can undergo more elongation before it breaks. [2] There is a correlation between bending diameter of the filament and the filament diameter. See KH Hillermeier, 1973, Freudenstadt. 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.
Manufacturing processes
Melting
There are two main types of glass fiber manufacture and two main types of glass fiber product. First, fiber is made either from a direct melt process or a marble remelt process. A marble is a small spherical toy usually made from Glass, Clay, or Agate. Both start with the raw materials in solid form. The materials are mixed together and melted in a furnace. A furnace is a device used for Heating The name derives from Latin fornax, Oven. Then, for the marble process, the molten material is sheared and rolled into marbles which are cooled and packaged. The marbles are taken to the fiber manufacturing facility where they are inserted into a can and remelted. The molten glass is extruded to the bushing to be formed into fiber. A mechanical bushing is a cylindrical lining designed to reduce friction and wear inside a hole or constrict and restrain motion of mechanical parts In the direct melt process, the molten glass in the furnace goes right to the bushing for formation. [4]
Formation
The bushing plate is the most important part of the machinery. A mechanical bushing is a cylindrical lining designed to reduce friction and wear inside a hole or constrict and restrain motion of mechanical parts This is a small metal furnace containing nozzles for the fiber to be formed through. A nozzle is a mechanical device or Orifice designed to control the characteristics of a Fluid flow as it exits (or enters an enclosed chamber or Pipe. It is almost always made of platinum alloyed with rhodium for durability. Platinum (ˈplætɪnəm is a Chemical element with the Atomic symbol Pt and an Atomic number of 78 Rh redirects here For other uses see Rh (disambiguation Rhodium (ˈroʊdiəm is a Chemical element with the symbol Platinum is used because the glass melt has a natural affinity for wetting it. Platinum (ˈplætɪnəm is a Chemical element with the Atomic symbol Pt and an Atomic number of 78 Wetting is the contact between a liquid and a solid surface resulting from intermolecular interactions when the two are brought together When bushings were first used they were 100% platinum and the glass wetted the bushing so easily it ran under the plate after exiting the nozzle and accumulated on the underside. A mechanical bushing is a cylindrical lining designed to reduce friction and wear inside a hole or constrict and restrain motion of mechanical parts Also, due to its cost and the tendency to wear, the platinum was alloyed with rhodium. In the direct melt process, the bushing serves as a collector for the molten glass. It is heated slightly to keep the glass at the correct temperature for fiber formation. In the marble melt process, the bushing acts more like a furnace as it melts more of the material. [1]
The bushings are what make the capital investment in fiber glass production expensive. The nozzle design is also critical. The number of nozzles ranges from 200 to 4000 in multiples of 200. The important part of the nozzle in continuous filament manufacture is the thickness of its walls in the exit region. It was found that inserting a counterbore here reduced wetting. Today, the nozzles are designed to have a minimum thickness at the exit. The reason for this is that as glass flows through the nozzle it forms a drop which is suspended from the end. As it falls, it leaves a thread attached by the meniscus to the nozzle as long as the viscosity is in the correct range for fiber formation. For other uses see Meniscus (anatomy and lens (optics. Meniscus, plural menisci, from the Greek for "crescent" The smaller the annular ring of the nozzle or the thinner the wall at exit, the faster the drop will form and fall away, and the lower its tendency to wet the vertical part of the nozzle. [1] The surface tension of the glass is what influences the formation of the meniscus. For E-glass it should be around 400 mN per m. [3]
The attenuation (drawing) speed is important in the nozzle design. Although slowing this speed down can make coarser fiber, it is uneconomic to run at speeds for which the nozzles were not designed. [1]
Continuous filament process
In the continuous filament process, after the fiber is drawn, a size is applied. Sizing or size is a Substance that is applied to Porous materials as a Glaze or Filler. This size helps protect the fiber as it is wound onto a bobbin. The particular size applied relates to end-use. While some sizes are processing aids, others make the fiber have an affinity for a certain resin, if the fiber is to be used in a composite. [4] Size is usually added at 0. 5–2. 0% by weight. Winding then takes place at around 1000 m per min. [2]
Staple fiber process
In staple fiber production, there are a number of ways to manufacture the fiber. The glass can be blown or blasted with heat or steam after exiting the formation machine. Usually these fibers are made into some sort of mat. The most common process used is the rotary process. Here, the glass enters a rotating spinner, and due to centrifugal force is thrown out horizontally. The air jets push it down vertically and binder is applied. Then the mat is vacuumed to a screen and the binder is cured in the oven. [5]
Laminating Operations
Filament Winding Operation
Fiberglass Sheet Laminating Operation
First, you have to mix resin with catalyst (e. g butanox LA), otherwise it won't go off for days/ weeks. Then you need wet out the mould with the resulting mixture, and put the sheets of fibreglass over it. You then roll them down into to mould using more resin, and make sure it is attached to the mould all over, and there is no air trapped in between the layers. Steel rollers are useful to make sure the resin is between all the layers, and the glass is wet right through, otherwise it doesn't stick. You have to be fast though, or the resin goes off and you have to start again.
Fiberglass Spray Lay-Up Operation
The fiberglass spray lay-up process is similar to the hand lay-up process but the difference comes from the application of the fiber and resin material to the mold. Fiberglass spray lay-up process is similar to the hand Lay-up process Spray-up is an open-molding composites fabrication process where resin and reinforcements are sprayed onto a mold. The resin and glass may be applied separately or simultaneously "chopped" in a combined stream from a chopper gun. Workers roll out the spray-up to compact the laminate. Wood, foam or other core material may then be added, and a secondary spray-up layer imbeds the core between the laminates. The part is then cured, cooled and removed from the reusable mold.
Fiberglass Hand Lay-Up Operation
Pultrusion Operation
Pultrusion is a manufacturing method used to make strong light weight composite materials, in this case fiberglass. Pultrusion is a continuous process of manufacturing of Composite materials with constant cross-section whereby reinforced Fibers are pulled through a Resin Composite materials (or composites for short are engineered Materials made from two or more constituent materials with significantly different physical or chemical Fibers (the glass material) are pulled from spools through a device that coats them with a resin. They are then typically heat treated and cut to length [6]. Pultrusions can be made in a variety of shapes or cross-sections such as a W or S cross-section. The word pultrusion describes the method of moving the fibers through the machinery. It is pulled through using either a hand over hand method or a continuous roller method. This is opposed to an extrusion which would push the material through dies. Extrusion is a process used to create objects of a fixed cross-sectional profile
Uses
End uses for regular fiber glass are mats, insulation, reinforcement, sound absorption, heat resistant fabrics, corrosion resistant fabrics and high strength fabrics. The 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 Fiber glass is also the main source of material used by the modern automobile industry.
Corrugated fiberglass panels are also widely used for outdoor canopy or greenhouse construction. These are thin, rigid panels with a wavy or zig-zag cross-section, usually a pale green or yellow color (although they are also available in other colors). They are usually available in widths of 2-4 feet and lengths of 6-16 feet. Overlapping one wave pattern on each edge is often sufficient to prevent most water or wind penetration through the seams.
See also
- Glass wool
- Basalt fiber
- Carbon fiber
- Fiberglass molding
- Glass microsphere
- Optical fiber
- Building insulation
- Gelcoat
Notes and references
- ^ a b c d e f Loewenstein, K. Glass wool is a form of Fibreglass where very thin strands of Glass are arranged into a spongy texture similar to Steel wool. Basalt fiber or fibre is a Material made from extremely fine Fibers of Basalt, which is composed of the Minerals Plagioclase Fiberglass molding is a process in which Fiberglass reinforced resin plastics are formed into useful shapes Glass microspheres are Microscopic spheres of Glass manufactured for wide a variety of uses in Research, Medicine, Consumer goods An optical fiber (or fibre) is a Glass or Plastic fiber that carries Light along its length Building insulation refers broadly to any object in a building used as Insulation for any purpose A gelcoat is a material used to provide a high quality finish on the visible surface of a fibre-reinforced Composite material. L. (1973). The Manufacturing Technology of Continuous Glass Fibers. New York: Elsevier Scientific, 2-94. ISBN 0-444-41109-7.
- ^ a b c d Gupta, V. B. ; V. K. Kothari (1997). Manufactured Fibre Technology. London: Chapman and Hall, 544-546. ISBN 0-412-54030-4.
- ^ a b c d Volf, Milos B. (1990). Technical Approach to Glass. New York: Elsevier. ISBN 0-444-98805-X.
- ^ a b c d Lubin, George (Ed. ) (1975). Handbook of Fiberglass and Advanced Plastic Composites. Huntingdon NY: Robert E. Krieger.
- ^ Mohr, J. G. ; W. P. Rowe (1978). Fiberglass. Atlanta: Van Nostrand Reindhold, 13. ISBN 0-442-25447-4.
- ^ [1]
7. Melliand Textilberichte 1/1969, Dortmund-Mengede, page 26-28, Glass fiber — its properties related to the filament fiber diameter. [Kh Hillermeier].
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