Fiberglass Totally Explained

Everything about Fibreglass totally explained

Fiberglass (also called fibreglass and glass fibre) is material made from extremely fine fibers of glass. 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.
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. 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 . It is marketed under the trade name Fiberglas, which has become a genericized trademark.

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. Glass, even as a fiber, has little crystalline structure (see amorphous solid). 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."
   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. Until this time all fiberglass had been manufactured as staple. When the two companies joined together to produce and promote fiberglass, they introduced continuous filament glass fibers. 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. These atoms then form a network bonded at the corners by sharing the oxygen atoms.
   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. In order to induce crystallization, it must be heated to temperatures above 1200°C for long periods of time. This was the first glass formulation used for continuous 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. C-glass was developed to resist attack from chemicals, mostly acids which destroy E-glass. The strain point is reached when the glass has a viscosity of 10^14.5 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.
   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. 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. 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.

Continuous filament process

In the continuous filament process, after the fiber is drawn, a size is applied. This size helps protect the fiber as it's 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.

Laminating Operations

Filament Winding Operation

Fiberglass Sheet Laminating Operation

First, you've 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's attached to the mould all over, and there's 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've 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. 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. 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 . 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.

Uses

End uses for regular fiber glass are mats, insulation, reinforcement, sound absorption, heat resistant fabrics, corrosion resistant fabrics and high strength fabrics. 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're 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.

Further Information

Get more info on 'Fibreglass'.

External Link Exchanges

Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:

<a href="http://fiberglass.totallyexplained.com">Fiberglass Totally Explained</a>

Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned.