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[[ملف:Glasfaser Roving.jpg|تصغير|حزمة من الألياف الزجاجية]]
'''الألياف الزجاجية''' {{إنج|Fiberglass}} (وتدعى الزجاج الليفي) او '''الفيبرجلاس''' (أو'''ألياف زجاجية''') (وتسمى أيضا '''زجاج بلاستيك مقوى'''بلاسيك زجاجي'''GRP''',<ref>{{Citation | last = Mayer | first = Rayner M. | title = Design with reinforced plastics | page = 7 | publisher = Springer | year = 1993 | url = http://books.google.com/books?id=XQFJego9nGUC&pg=PA7 | isbn = 978-0-85072-294-9}}</ref>
هي [[مادة]] مصنوعة من ألياف رفيعة جداً من [[الزجاج]]. وهذه الألياف قد تكون أدق من الشعر البشري بمرات كثيرة، وهي في مظهرها وملمسها ك[[حرير|الحرير]]. والألياف الزجاجية المرنة أقوى من الصلبة تحترق أو تتمدد أو تصدأ أو تبهت.<ref>{{Citation | last = Nawy | first =Edward G. | title = Fundamentals of high-performance concrete | page = 310 | publisher = John Wiley and Sons | year = 2001 | edition = 2 | url = http://books.google.com/books?id=W6BNygdZLJUC&pg=PA310 | isbn = 978-0-471-38555-4 }}</ref>)
الألياف الزجاجية هي، مادة قوية للغاية، وخفيفة الوزن. على الرغم من خصائص القوة هي أقل إلى حد ما من [[ليف كربون|الكربون الليفي]]، وأنه أقل قاسية، والمواد غير عادة أقل هشاشة، والمواد الخام هي أقل تكلفة بكثير. قوتها السائبة وخصائص الوزن هي أيضا مواتية جدا بالمقارنة مع المعادن، وأنه يمكن أن تتشكل بسهولة باستخدام عمليات الصب.
الاستخدامات الشائعة للألياف الزجاجية تشمل [[الطائرات]] عالية الأداء ([[طائرة شراعية|الطائرات الشراعية]])، و[[القوارب]]، و[[السيارات]] ، و[[الحمامات]] ، أحواض المياه الساخنة، و [[خزان ماء|خزانات المياه]] , و[[سقف|السقوف]] ، و[[انبوب|الأنابيب]] ، التغليف ، مصبوب تقويم الأعضاء او القوالب ، [[لوح تزلج|الواح التزلج]] على [[الماء]] وجلود الابواب الخارجية.
'''Fiberglass''' (or '''fibreglass''') (also called '''glass-reinforced plastic''', '''GRP''',<ref>{{Citation | last = Mayer | first = Rayner M. | title = Design with reinforced plastics | page = 7 | publisher = Springer | year = 1993 | url = http://books.google.com/books?id=XQFJego9nGUC&pg=PA7 | isbn = 978-0-85072-294-9}}</ref> '''glass-fiber reinforced plastic''', or '''GFRP'''<ref>{{Citation | last = Nawy | first =Edward G. | title = Fundamentals of high-performance concrete | page = 310 | publisher = John Wiley and Sons | year = 2001 | edition = 2 | url = http://books.google.com/books?id=W6BNygdZLJUC&pg=PA310 | isbn = 978-0-471-38555-4}}</ref>) is a [[fiber reinforced plastic|fiber reinforced polymer]] made of a [[plastic]] matrix reinforced by fine [[glass fiber|fibers of glass]]. It is also known as '''GFK''' (for {{Lang-de|Glasfaserverstärkter Kunststoff}}).
Fiberglass is a lightweight, extremely strong, and robust material, and is used for many products. 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 a [[thermosetting plastic]] (most often [[epoxy]], [[polyester]] or [[vinylester]]) or [[thermoplastic]].
Common uses of fiberglass include high performance aircraft (gliders), boats, automobiles, baths, hot tubs, septic tanks, water tanks, roofing, pipes, cladding, [[orthopedic cast|casts]], surfboards and external door skins.
== Applications ==
Fiberglass is an immensely versatile material which combines its light weight with an inherent strength to provide a weather resistant finish, with a variety of surface textures.
The development of fiber-reinforced plastic for commercial use was being extensively researched in the 1930s. It was particularly of interest to the aviation industry. Mass production of glass strands was accidentally discovered in 1932 when a researcher at the Owens-Illinois directed a jet of compressed air at a stream of molten glass and produced fibers. Owens joined up with the Corning company in 1935 and the method was adapted by Owens Corning to produce its patented "Fiberglas" (one "s"). A suitable resin for combining the "Fiberglas" with a plastic was developed in 1936 by du Pont. The first ancestor of modern polyester resins is Cyanamid's of 1942. Peroxide curing systems were used by then.
During World War II, fiberglass was developed as a replacement for the molded plywood used in aircraft [[radome]]s (fiberglass being [[Transparency (telecommunication)|transparent]] to [[microwaves]]). Its first main civilian application was for building of [[boat]]s and sports-car bodies, where it gained acceptance in the 1950s. Its use has broadened to the automotive and sport equipment sectors as well as aircraft, although its use there is now partly being taken over by [[carbon fiber]] which weighs less per given volume and is stronger both by volume and by weight. Fiberglass uses also include [[hot tub]]s, pipes for drinking water and sewers, office plant display containers and flat roof systems.
Advanced manufacturing techniques such as [[pre-preg]]s and [[fiber]] [[roving]]s extend the applications and the tensile strength possible with fiber-reinforced plastics.
Fiberglass is also used in the [[telecommunications]] industry for [[shroud]]ing the visual appearance of [[Antenna (radio)|antennas]], due to its [[radio frequency|RF]] permeability and low signal [[attenuation (electromagnetic radiation)|attenuation]] properties. It may also be used to shroud the visual appearance of other equipment where no signal permeability is required, such as equipment cabinets and [[steel]] support structures, due to the ease with which it can be molded, manufactured and painted to custom designs, to blend in with existing structures or brickwork. Other uses include sheet form made electrical insulators and other structural components commonly found in the power industries.
Because of fiberglass's light weight and durability, it is often used in protective equipment, such as helmets. Many sports use fiberglass protective gear, such as modern goaltender masks and newer baseball catcher's masks.
=== Storage tanks ===
[[ملف:Milwaukee tanks.jpg|right|thumb|Several large fiberglass tanks at an airport]]
[[Storage tank]]s can be made of fiberglass with capacities up to about 300 [[tonne]]s. The smaller tanks can be made with chopped strand mat cast over a thermoplastic inner tank which acts as a [[Optical fiber#Preform|preform]] during construction. Much more reliable tanks are made using woven mat or filament wound fibre with the fibre orientation at right angles to the [[hoop stress]] imposed in the side wall by the contents. They tend to be used for chemical storage because the plastic liner (often [[polypropylene]]) is resistant to a wide range of strong chemicals. Fiberglass tanks are also used for [[septic tank]]s.
=== House building ===
[[ملف:Baggins-end-dome-4.jpg|right|thumb|A fiberglass dome house in [[Davis, California]]]]
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. The use of fiberglass for these applications provides for a much faster installation and due to the reduced weight manual handling issues are reduced. With the advent of high volume manufacturing processes it is possible to construct fiberglass brick effect panels which can be used in the construction of composite housing. These panels can be constructed with the appropriate insulation which reduces heat loss.
=== 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
== Construction methods ==
=== Fiberglass hand lay-up operation ===
A release agent, usually in either wax or liquid form, is applied to the chosen mold. This will allow the finished product to be removed cleanly from the mold. Resin—typically a 2-part polyester, vinyl or epoxy—is mixed with its hardener and applied to the surface. Sheets of fibreglass matting are laid into the mold, then more resin mixture is added using a brush or roller. The material must conform to the mold, and air must not be trapped between the fiberglass and the mold. Additional resin is applied and possibly additional sheets of fiberglass. Hand pressure, vacuum or rollers are used to make sure the resin saturates and fully wets all layers, and any air pockets are removed. The work must be done quickly enough to complete the job before the resin starts to cure, unless high temperature resins are used which will not cure until the part is warmed in an oven.<ref name="Aird">{{cite book|author=Forbes Aird|title=Fiberglass & Composite Materials: An Enthusiast's Guide to High Performance Non-Metallic Materials for Automotive Racing and Marine Use|url=http://books.google.com/books?id=ileMYXGZ3OQC&pg=PA86|accessdate=12 June 2012|date=1 April 1996|publisher=Penguin|isbn=978-1-55788-239-4|pages=86–}}</ref> In some cases, the work is covered with plastic sheets and vacuum is drawn on the work to remove air bubbles and press the fiberglass to the shape of the mold.<ref name="Vacuum bagging composites">[http://www.nextcraft.com/vacuum_bagging_01.html An Introduction to Vacuum Bagging Composites], NextCraft.</ref>
=== 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.
=== Pultrusion operation ===
[[ملف:Pultrusion process 01.png|thumb|300px|right|Diagram of the [[pultrusion]] process.]]
Pultrusion is a manufacturing method used to make strong, lightweight 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.
=== Chopped strand mat ===
'''Chopped strand mat''' or '''CSM''' is a form of reinforcement used in fiberglass. It consists of [[glass-fibre|glass fibers]] laid randomly across each other and held together by a binder.
It is typically processed using the hand lay-up technique, where sheets of material are placed in a mold and brushed with resin. Because the binder dissolves in resin, the material easily conforms to different shapes when wetted out. After the resin cures, the hardened product can be taken from the mold and finished.
Using chopped strand mat gives a fiberglass with [[isotropic]] in-plane material properties.
== Warping ==
One notable feature of fiberglass is that the resins used are subject to contraction during the curing process. For polyester this contraction is often of the order of 5-6%, and for epoxy it can be much lower, about 2%.
When formed as part of fiberglass, because the fibers don't contract, the differential can create changes in the shape of the part during cure. Distortions will usually appear hours, days or weeks after the resin has set.
While this can be minimised by symmetric use of the fibers in the design, nevertheless internal stresses are created, and if these become too great, then cracks will form.
== Health problems ==
[[ملف:Luftströmung.jpg|thumb|Air flow test for the extraction and filtration of [[styrene]] vapors in a production hall for GRP yachts]]
The National Toxicology Program ("NTP"), in June 2011, removed from its Report on Carcinogens all biosoluble glass wool used in home and building insulation and for non-insulation products.<ref name="dhhs">{{Citation
| title = National Institute of Environmental Health Sciences, National toxicology Program, Fact Sheet, "The Report on Carcinogens," June 2011 | url = http://ntp.niehs.nih.gov/ntp/roc/twelfth/profiles/GlassWoolFibers.pdf
| year = 2011
| last1 = Department of Health and Human Services
| accessdate = 2013-02-05 }}
</ref> However, NTP classifies as Fibrous Glass Dust "Reasonably anticipated to be a human carcinogen (Certain Glass Wool Fibers (Inhalable))".<ref>https://www.osha.gov/dts/chemicalsampling/data/CH_242120.html</ref> Similarly, California's Office of Environmental Health Hazard Assessment ("OEHHA"), in November 2011, published a modification to its Proposition 65 listing to include only "Glass wool fibers (inhalable and biopersistent)."<ref>46-Z California Regulatory Notice Register, P.1878 (November 18, 2011).</ref> The U.S. NTP and California's OEHHA action means that a cancer warning label for biosoluble fiber glass home and building insulation is no longer required under Federal or California law. All fiber glass wools commonly used for thermal and acoustical insulation were reclassified by the International Agency for Research on Cancer ("IARC") in October 2001 as Not Classifiable as to carcinogenicity to humans (Group 3).<ref name="iarc.fr">IARC Press Release, 24 October 2001 (http://www.iarc.fr/en/media-centre/pr/2001/pr137.html)</ref>
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. The glass wool epidemiology studies have been reviewed by a panel of international experts convened by the International Agency for Research on Cancer ("IARC"). These experts concluded: "Epidemiologic studies published during the 15 years since the previous IARC monographs review of these fibres in 1988 provide no evidence of increased risks of lung cancer or mesothelioma (cancer of the lining of the body cavities) from occupational exposures during the manufacture of these materials, and inadequate evidence overall of any cancer risk."<ref name="iarc.fr"/> Similar reviews of the epidemiology studies have been conducted by the Agency for Toxic Substances and Disease Registry ("ATSDR"),<ref>Toxicological Profile for SynthethicVitreous Fibers (U.S. Department of Health and Human Services, Public Health Services, Agency for Toxic Substances and Disease Registry), September 2004, pp. 5, 18</ref> the National Toxicology Program,<ref>Charles William Jameson, "Comments on the National Toxicology Program's Actions In Removing Biosoluble Glass Wool Fibers From The Report On Carcinogens," September 9, 2011.</ref> the National Academy of Sciences<ref>NRC Subcommittee on Manufactured Vitreous Fibers. 2000. Review of the U.S. Navy's Exposure Standard for Manufactured Vitreous Fibers. National Academy of Sciences, National Research Council, Washington, D.C.: National Academy Press.</ref> and Harvard's Medical and Public Health Schools<ref>Lee, I-Min, et al, "Man-made Vitreous Fibers and Risk of Respiratory System Cancer: A Review of the Epidemiologic Evidence" 37 J. Occup. & Env. Med. 725 (1995).</ref> which reached the same conclusion as IARC that there is no evidence of increased risk from occupational exposure to glass wool fibers.
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.<ref>Labor, United States Department of (2005), Occupational Safety & Health Administration, Chemical Sampling Information, CAS Registry Number: 65997-17-3 (Fibrous Glass)</ref> Scientific evidence demonstrates that fiber glass is safe to manufacture, install and use when recommended work practices are followed to reduce temporary mechanical irritation.<ref>North American Insulation Manufacturers Association ("NAIMA"), Insulation Facts #62 "Health and Safety Facts for Fiber Glass", Pub. No. N040, May 2012.</ref>
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.<ref name=Corning2007>{{Citation
| title = Fiberglass Thermal Batt, Product Data Sheet
| url = http://www.owenscorning.com/comminsul/documents/thermalbatt_eng.pdf
| year = 2007
| author = Corning, Owens
| accessdate = 2012-02-23
}}</ref>
While the resins are cured, [[styrene]] vapors are released. These are irritating to mucous membranes and respiratory tract. Therefore, the Hazardous Substances Ordinance in Germany dictate a maximum occupational exposure limit of 86 mg/m³. In certain concentrations may even occur a potentially explosive mixture.
Further manufacture of GRP components (grinding, cutting, sawing) goes along with the emission of fine dusts and chips containing glass filaments as well as of tacky dust in substantial quantities. These affect people's health and functionality of machines and equipment.
To ensure safety regulations are adhered to and efficiency can be sustained, the installation of effective extraction and filtration equipment is needed.<ref>Türschmann/Jakschik/Rother: ''[http://www.ult.de/filebase/whitepaper_1103_en.pdf White Paper, Topic: "Clean Air in the Manufacture of Glass Fibre Reinforced Plastic (GRP) Parts", March 2011]''</ref>
== Examples of fiberglass use ==
[[ملف:Fiberglass Kayaks.jpg|thumb|Kayaks made of fiberglass]]
* [[Surfboard]]s, tent poles
* [[Glider (sailplane)|Gliders]], [[kit car]]s, sports cars, microcars, karts, bodyshells, boats, [[kayak]]s, flat roofs, lorries, [[K21]] Infantry Fighting Vehicle
* [[Minesweeper (ship)|Minesweeper]] [[Hull (watercraft)|hulls]]
* Pods, domes and architectural features where a light weight is necessary
* High end [[bicycles]]{{citation needed|date=January 2014}}
* Bodyparts for and entire automobiles, such as the [[Anadol]], [[Reliant]], Quantum Quantum Coupé, [[Chevrolet Corvette]] and [[Studebaker Avanti]], and [[DeLorean DMC-12]] under body
* Antenna covers and structures, such as [[radome]]s, UHF broadcasting antennas, and pipes used in hex beam antennas for amateur radio communications
* [[FRP tanks and vessels]]: FRP is used extensively to manufacture chemical equipment and tanks and vessels. [[BS4994]] is a British standard related to this application
* Most commercial [[velomobile]]s
* Most [[printed circuit board]]s used in electronics consist of alternating layers of copper and fibreglass [[FR-4]]
* Large commercial [[wind turbine]] blades
* RF coils used in [[MRI scanner]]s
* Sub sea installation protection covers
* Re-enforcement of [[asphalt pavement]], as a fabric or mesh interlayer between lifts<ref>{{cite web |title= Flexible Pavement Preservation Ch. 12 Interlayers| url=http://www.dot.ca.gov/hq/maint/FPMTAGChapter12_5-28-09Final.pdf |publisher=Caltrans Division of Maintenance |date=January 27, 2009}}</ref>
* Protective helmets used in various sports
* [[Orthopedic cast]]s<ref>{{citation|title=Practice of Pediatric Orthopedics|edition=2nd|first=Lynn T.|last=Staheli|publisher=Lippincott Williams & Wilkins|year=2006|isbn=9781582558189|page=68|url=http://books.google.com/books?id=fxqFdiyrxQcC&pg=PA68}}</ref>
* [[FRP grating|Fiberglass Grating]] is used for walkways on ships, oil rigs and in factories
* Fiber reinforced composite columns
== التاريخ ==
== الألياف ==
[[ملفFile:Glass reinforcements.jpg|thumb|يتم توفير تعزيزات الزجاج المستخدمة في الألياف الزجاجية في الأشكال المادية المختلفة، والأرضيات الجيدة ، مقطعة أو منسوجة.]]
على عكس الألياف الزجاجية المستخدمة للعزل ، فالهيكل النهائي يكون قوي ، كما يجب أن تكون أسطح الألياف شبه خالية تماما من العيوب ، وهذا يسمح للألياف لتصل إلى gigapascal و [[قوة شد]] المثلى. إذا كان هنالك قطعة كبيرة زجاجية بها عيب حر ، فإنه سيكون من بنفس القدر كما في الألياف الزجاجية، ومع ذلك ، عادة يصبح غير عملي إنتاج المواد السائبة في الحالة الخالية من العيوب خارج الظروف المختبرية
.<ref name=newscience>{{cite book|author=J E Gordon|title=The New Science of Strong Materials: Or Why You Don't Fall Through the Floor|url=http://books.google.com/books?id=axW-iYrhQ1YC|accessdate=12 June 2012|date=28 March 1991|publisher=Penguin Books Limited|isbn=978-0-14-192770-1}}</ref>
[[ملف:Glass reinforcements.jpg|thumb|Glass reinforcements used for fiberglass are supplied in different physical forms, microspheres, chopped or woven.]]
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 strength]]s. If a bulk piece of glass were to be defect free, then it would be equally as strong as glass fibers; however, it is generally impractical to produce bulk material in a defect-free state outside of laboratory conditions.<ref name=newscience>{{cite book|author=J E Gordon|title=The New Science of Strong Materials: Or Why You Don't Fall Through the Floor|url=http://books.google.com/books?id=axW-iYrhQ1YC|accessdate=12 June 2012|date=28 March 1991|publisher=Penguin Books Limited|isbn=978-0-14-192770-1}}</ref>
=== الانتاج ===
عملية تصنيع ألالياف الزجاجية لتكون مناسبة تدعم باستخدام أفران كبيرة لإذابتها تدريجيا مع [[رمل]] [[السيليكا]] , [[الحجر الجيري]] ، [[طين الكاولين]]، [[فلورسبار]] ، colemanite ، والدولوميت والمعادن الأخرى حتى تتحول إلى صورة سائلة . ثم يتم سحبها من خلال المقابس ، والتي هي حزم من فتحات صغيرة جدا (قطرها عادة بين 5-25 ميكرومتر ل«E» - زجاج ، 9 ميكرومتر ل«S» - زجاج). هذه الخيوط من ثم تغلف بحجمها وتصبح (مغلفة) مع محلول كيماوي . يتم وضع الشعيرات الفردية معا في حزمة واحدة بأعداد كبيرة لتسهيل نقلها.
الألياف الزجاجية تتشكل عندما تتحول الي جدائل رقيقة من [[السيليكا]] (أي صيغة أخرى من الزجاج) إلي العديد من الألياف بأقطار صغيرة ،تجعلها مناسبة لعملية [[نسج|النسج]]. عندما يصبح الزجاج ليف يكون له [[تركيب بلوري]] صغير.
إن خواص التشكيل للزجاج في حالته الناعمة تشبه كثيراً خواصه عندما ينسج إلى الياف. هناك نوعان من الألياف الزجاجية الأكثر استعمالاً وهما : [[S-glass]] و[[E-glass]]
E-glass لديه خاصية عزل ممتازة فهو قادر على تحمل حتى درجة حرارة 815 درجة مئوية . أما S-glass فله قابلية عالية للشد وهو اصلب من E-glass.
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). These filaments are then ''sized'' (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.
== التركيب الكيميائي ==
إن أساس النسيج للألياف الزجاجية هو [[سيليكا|السيليكا]] SiO2. في شكله الصافي يوجد [[مبلمر|كمبلمر]] SiO2)n). ولايوجد درجة انصهار حقيقية للألياف الزجاجية لكنها تلين عند [[درجة حرارة]] 2000 درجة مئوية.
An individual structural glass fiber is both stiff and strong in [[Tension (physics)|tension]] and [[compression (physical)|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.<ref name=newscience/> 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.
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.
{| class="wikitable"
|-
! Material !! Specific gravity !! Tensile strength MPa (ksi) !! Compressive strength MPa (ksi)
|-
| Polyester resin (Not reinforced)<ref name=ecfibre>[http://www.ecfibreglasssupplies.co.uk/t-GlassReinforcedPlastics.aspx East Coast Fibreglass Supplies: Guide to Glass Reinforced Plastics]</ref>
| 1.28
| {{convert|55|MPa|ksi|sigfig=3|abbr=values}}
| {{convert|140|MPa|ksi|sigfig=3|abbr=values}}
|-
|Polyester and Chopped Strand Mat Laminate 30% E-glass<ref name=ecfibre/>
|1.4
|{{convert|100|MPa|ksi|sigfig=3|abbr=values}}
|{{convert|150|MPa|ksi|sigfig=3|abbr=values}}
|-
|Polyester and Woven Rovings Laminate 45% E-glass<ref name=ecfibre/>
|1.6
|{{convert|250|MPa|ksi|sigfig=3|abbr=values}}
|{{convert|150|MPa|ksi|sigfig=3|abbr=values}}
|-
|Polyester and Satin Weave Cloth Laminate 55% E-glass<ref name=ecfibre/>
|1.7
|{{convert|300|MPa|ksi|sigfig=3|abbr=values}}
|{{convert|250|MPa|ksi|sigfig=3|abbr=values}}
|-
|Polyester and Continuous Rovings Laminate 70% E-glass<ref name=ecfibre/>
|1.9
|{{convert|800|MPa|ksi|sigfig=3|abbr=values}}
|{{convert|350|MPa|ksi|sigfig=3|abbr=values}}
|-
|E-Glass Epoxy composite<ref name=tubeshop>[http://www.carbonfibertubeshop.com/tube%20properties.html Tube Properties]</ref>
|1.99
|{{convert|1,770|MPa|ksi|sigfig=3|abbr=values}}
|
|-
|S-Glass Epoxy composite<ref name=tubeshop/>
|1.95
|{{convert|2,358|MPa|ksi|sigfig=3|abbr=values}}
|
|}
== مراحل التصنيع ==
تصنع الألياف إما عن طريق عملية الانصهار المباشر أو عن طريق عملية إعادة صهر قطع كروية زجاجية صغيرة. وكلتا الطريقتين تبدأ بمواد أولية في الشكل الصلب. يتم خلط المواد الخام ببعضها وتصهر في [[فرن]]. ثم في طريقة صهر القطع الكروية الصغيرة، تأخذ المواد المنصهرة من الفرن ثم تصق وتطوي إلي كرات صغيرة ثم تبرد وتغلف. ثم تُأخذ الكرات الزجاجية لمصنع تصنيع الألياف حيث تعبأ في علب ويعاد صهرها مرة أخرى في فرن كهربائي خاص. ثم تنساب المادة المصهورة عبر ثقوب صغيرة جداً لتتحول إلى الياف.أما في طريقة الصهر المباشر، يؤخذ الزجاج المصهور مباشرة من الفرن إلى آلة الكبس لتتشكل إلى ألياف.
'''التشكيل'''
آلة الكبس هو الجزء الأكثر أهمية في الالآت. هذا الفرن المعدني الصغير الذي يحتوي على خراطيم ليتشكل من خلالها الليف. وفي الغالب تقريباً يصنع من [[بلاتين|البلاتين]] مخلوطاً مع [[راديوم|الراديوم]] ليكسبه المتانة. حيث يسقط [[زجاج|الزجاج]] المصهور على أسطوانة تدور منطوية على مكوكات، كما تُطوى الخيوط على البكرات. ولأن الأسطوانة تدور بسرعة أكبر من السرعة التي ينساب بها الزجاج فإن هناك شَدَّادة، تشد الألياف وتطيلها إلى أن تتخذ شكل حبال دقيقة ثابتة. وتستطيع الأسطوانة أن تسحب 3,2كم من الألياف في الدقيقة الواحدة. ويمكن سحب أكثر من 150كم من الألياف من كرية زجاجية واحدة ذات قطر طوله 16مم. ويُمكن لف الألياف معاً في شكل خيوط وحبال، كما يمكن غزل الخيوط في نسيج وشرائط وأنواع أخرى من الأقمشة. أما في عملية الصهر المباشر، تُحذف خطوات صناعة الكريات الزجاجية.
== المراجع ==
{{مراجع|2}}
{{مراجع}}
== أنظر ايضا ==
{{تصنيف كومنز|Fibreglass}}
* [[خرسانة مسلحة بألياف زجاجية]]
* [[ألياف النسيج]]
{{ألياف النسيج}}
[[{{تصنيف:ألياف اصطناعية]]كومنز|Fibreglass}}
[[تصنيف:اختراعات أمريكية]]
[[تصنيف:اختراعات بريطانية]]
[[تصنيف:اختراعات 1938]]
[[تصنيف:تطبيقات الزجاج]]
[[تصنيف:مواد مركبة]]
[[تصنيف:ألياف اصطناعية]]
[[تصنيف:نسيج]]
{{وصلة مقالة جيدة|en}}
[[en:Fiberglass]]
| 