FIBER GLASS
Fiberglass (or fibreglass) (also called glass-reinforced plastic, GRP,[1] glass-fiber reinforced plastic, or GFRP[2]), is a fiber reinforced polymer made of a plastic matrix reinforced by fine fibers of glass. It is also known as GFK.( Glasfaserverstärkter Kunststoff ).
Fiberglass is a lightweight, extremely strong, and robust material. Although strength properties are somewhat lower than carbon fiber and it is less stiff, the material is typically far less brittle, and the raw materials are much less expensive. Its bulk strength and weight properties are also very favorable when compared to metals, and it can be easily formed using molding processes. The plastic matrix may be epoxy, a thermosetting plastic (most often polyester or vinylester) or thermoplastic.
Common uses of fiberglass include boats, automobiles, baths, hot tubs, water tanks, roofing, pipes, cladding, casts and external door skins.
FIBER:-
Unlike glass fibers used for insulation, for the final structure to be strong, the fiber’s surfaces must be almost entirely free of defects, as this permits the fibers to reach gigapascal tensile strengths. If a bulk piece of glass were to be defect free, then it would be equally as strong as glass fibers; however, it’s generally impractical to produce bulk material in a defect-free state outside of laboratory conditions.
PRODUCTION:-
The manufacturing process for glass fibers suitable for reinforcement uses large furnaces to gradually melt the silica sand, limestone, kaolin clay, fluorspar, colemanite, dolomite and other minerals to liquid form. Then it is extruded through bushings, which are bundles of very small orifices (typically 5–25 micrometres in diameter for E-Glass, 9 micrometres for S-Glass).
The Review on The Use of Waste Glass as Construction Material
Introduction Waste glass is of great concern in some developed countries, particularly in the urban areas. This is because of the amount of waste material generated from both municipal and construction sources, and the lack of waste disposal areas to receive the material. Countries like Japan, the United States of America, and Australia have taken the initiative to invest in the recycling of glass ...
These filaments are thensized (coated) with a chemical solution. The individual filaments are now bundled together in large numbers to provide a roving. The diameter of the filaments, as well as the number of filaments in the roving determine its weight. This is typically expressed in yield-yards per pound (how many yards of fiber in one pound of material, thus a smaller number means a heavier roving, example of standard yields are 225yield, 450yield, 675yield) or in tex-grams per km (how many grams 1 km of roving weighs, this is inverted from yield, thus a smaller number means a lighter roving, examples of standard tex are 750tex, 1100tex, 2200tex).
These rovings are then either used directly in a composite application such as pultrusion, filament winding (pipe), gun roving (automated gun chops the glass into short lengths and drops it into a jet of resin, projected onto the surface of a mold), or used in an intermediary step, to manufacture fabrics such as chopped strand mat (CSM) (made of randomly oriented small cut lengths of fiber all bonded together), woven fabrics, knit fabrics or uni-directional fabrics.
SIZING:-
A sort of coating, or primer, is used which both helps protect the glass filaments for processing/manipulation as well as ensure proper bonding to the resin matrix, thus allowing for transfer of shear loads from the glass fibers to the thermoset plastic. Without this bonding, the fibers can ‘slip’ in the matrix and localised failure would ensue.
PROPERTIES:-
An individual structural glass fiber is both stiff and strong in tension and compression—that is, along its axis. Although it might be assumed that the fiber is weak in compression, it is actually only the long aspect ratio of the fiber which makes it seem so; i.e., because a typical fiber is long and narrow, it buckles easily. On the other hand, the glass fiber is weak in shear—that is, across its axis. Therefore if a collection of fibers can be arranged permanently in a preferred direction within a material, and if the fibers can be prevented from buckling in compression, then that material will become preferentially strong in that direction.
The Essay on History of Fiber Optics
Daniel Colladon and Jacques Babinet demonstrated the principle of guiding light by refraction. * It was followed by a public demonstration by John Tyndal in 1852. In 1870, Tyndal wrote about the property of total internal reflection in his book about the nature of light. * In 1880, Alexander Graham Bell and Sumner Tainter invented the Photophone, a device capable of transmitting sound waves over ...
Furthermore, by laying multiple layers of fiber on top of one another, with each layer oriented in various preferred directions, the stiffness and strength properties of the overall material can be controlled in an efficient manner. In the case of fiberglass, it is the plastic matrix which permanently constrains the structural glass fibers to directions chosen by the designer. With chopped strand mat, this directionality is essentially an entire two dimensional plane; with woven fabrics or unidirectional layers, directionality of stiffness and strength can be more precisely controlled within the plane. A fiberglass component is typically of a thin “shell” construction, sometimes filled on the inside with structural foam, as in the case of surfboards. The component may be of nearly arbitrary shape, limited only by the complexity and tolerances of the mold used for manufacturing the shell.
Material | Specific gravity | Tensile strength MPa (ksi) | Compressive strength MPa (ksi) |
Polyester resin (unreinforced) | 1.28 | 55 (7.98) | 140 (20.3) |
Polyester and Chopped Strand Mat Laminate 30% E-glass | 1.4 | 100 (14.5) | 150 (21.8) |
Polyester and Woven Rovings Laminate 45% E-glass | 1.6 | 250 (36.3) | 150 (21.8) |
Polyester and Satin Weave Cloth Laminate 55% E-glass | 1.7 | 300 (43.5) | 250 (36.3) |
Polyester and Continuous Rovings Laminate 70% E-glass | 1.9 | 800 (116) | 350 (50.8) |
E-Glass Epoxy composite | 1.99 | 1,770 (257) | |
S-Glass Epoxy composite | 1.95 | 2,358 (342) | |
HEALTH PROBLEMS:-
The National Toxicology Program classifies inhalable glass wool fibers as “[r]easonably anticipated to be a human carcinogen.”Some fiberglass products warn of “possible cancer hazard by inhalation”. The European Union and Germany classify synthetic vitreous fibers as possibly or probably carcinogenic, but fibers can be exempt from this classification if they pass specific tests.Evidence for these classifications is primarily from studies on experimental animals and mechanisms of carcinogenesis. Studies of fiberglass factory workers show significant increases in lung cancer but do not show clear exposure-response relationships and maybe confounded by the effects of smoking. The Environmental Research Foundation has documented significant efforts by the fiberglass industry to prevent or remove cancer causing classifications.
The Essay on The Glass Menagerie 8
THE GLASS MENAGERIE The rules about raising children are the most sacred of all rules. They are authenticated by religious teaching and reinforced in our school systems. Our families are the places where we have our source relationships. Families are where we first learn about ourselves in the mirroring eyes of our parents, where we see ourselves for the first time. In families we learn about ...
Fiberglass will irritate the eyes, skin and the respiratory system. Potential symptoms include irritation of eyes, skin, nose, throat; dyspnea (breathing difficulty); sore throat, hoarseness and cough.
Fiberglass is resistant to mold but growth can occur if fiberglass becomes wet and contaminated with organic material. Fiberglass insulation that has become wet should be inspected for evidence of residual moisture and contamination. Contaminated fiberglass insulation should be promptly removed.
Dust development in the processing of components made of fiberglass-reinforced plastics
APPLICATION:-
* PIPING:-
GRP and GRE pipe systems can be used for a variety of applications, above and under the ground.
Firewater systems
Cooling water systems
Drinking water systems
Waste water systems/Sewage systems
Gas systems
* STORAGE TANKS:-
Storage tanks can be made of fiberglass with capacities up to about 300 tonnes. The smaller tanks can be made with chopped strand mat cast over a thermoplastic inner tank which acts as a preform during construction.
* HOUSE BUILDING:-
Glass reinforced plastics are also used in the house building market for the production of roofing laminate, door surrounds, over-door canopies, window canopies and dormers, chimneys, coping systems, heads with keystones and sills.
