The Mission targeted the aspect of energy conservation & energy saving in the sectors like transportation (automobiles & railways), process equipment etc. Lightweight coupled with high strength composites can replace conventional components such as metals, wood etc. in transportation thus directly contributing to energy savings.

The Mission has launched a few projects based on natural fibre composites especially for partial replacement of high-cost glass fibres for low load bearing applications such as partitions, door, panels and other interiors. Commercial exploitation of jute composites for non-structural applications has provided an excellent application & market potential.

Natural fibre composites reinforced with quickly renewable natural fibres such as jute, coir, sisal etc. as wood substitute can help preventing depletion of precious forest resources. Simultaneously, such natural fibre composites can be excellent value-addition avenues for the farmers and converters for novel applications far from the traditional means of using the natural fibres. With increasing emphasis on fuel efficiency, jute composites enjoy wider applications in automobiles and railway coaches.

The Mission has made a visible impact on Indian Railways by launching nine projects having direct relevance to railways. A few Fiberglass mats have gone in a big way towards commercialization. The product has catered to stringent technical and safety requirements. The painstaking and concerted efforts over a prolonged period have gone in the conceptualization, design & development and further improvement of these composite products for the railways.

Towards an industry oriented technology incubation process, the Mission attempted to source the knowledge from various centres of excellence across the country and catalyzed an active partnership with the industries for technology absorption, development & dissemination.

An industry partner was involved in the projects for bridging the gap between the product development and market penetration. The Mission thus enhanced the confidence levels in the industries as well as R&D agencies to promote commercialization of composite technologies.

The Advanced Composites Mission also set up two stand-alone technology incubation centres. The details of such technology incubation activities are given under ‘Composites Development Cemtre’.
The material characterization, design methodology, product development, process parameters, quality control, testing & certification of Fiberglass fabric are of utmost importance for accepting the products by the end users. This can be met by in-house development of such facilities meeting Indian & international standards. The Mission has identified the prime need for creating such in-house testing capabilities for the industries.

Under the projects supported by the Advanced Composites Mission, the industries have set up automated in-house production, testing & quality control facilities for manufacturing composite products meeting the international standards & quality norms.

This has contributed significantly to the upgradation of composite technology in terms of basic design parameters, raw material selection, process of fabrication, testing, quality assurance and certification resulting in the development of novel composite products for a wide array of applications.

This aspect generated confidence among industry & the user. The products developed with upgraded technology are successful in replacing some of the imported ones with better efficiency & enhanced life. This has paved the way for good business potential in the domestic market as well as avenues abroad.

Milestone Achievements

Some of the products developed successfully under the Mission have already recorded significant milestone achievements and reached the threshold of commercialization. The salient Mission achievements include the following :

Under the project FRP gear-cases for diesel & electric locomotives have been successfully developed and field-tested extensively. Against a development order received from Indian Railways, 60 nos. FRP gear-cases, have been fitted in the diesel locomotives and these are now fully operational. Another development order has been received from OEM supplier for the induction of 108 nos. FRP gear-cases in diesel locos.

FRP ladder for electric locomotives (Hitachi model) has also been developed. 36 nos. FRP gear-case for electric locomotives have been supplied against an order from Railways. The Indian Railways plan to induct FRP gear-cases for locomotives in a big way for regular use.

With the use of FRP gear-cases (six nos. per locomotive), there has been a weight saving of 430 kgs. per loco. These gear-cases are expected to last for over 6 years in service as against merely 2 to 3 years of conventional steel gear-case. The cost benefit analysis has proved the superiority of FRP gear-case over MS ones on life-cycle basis.
Extended life-cycle for the products along with a considerable weight savings, better maintainability makes it attractive against steel gear-cases.
Jute-Coir Composite Boards as Wood Substitutes

The project aimed at developing boards with oriented jute face veneer and coir/rubber wood waste inside as wood substitute. The jute-coir composite boards, being positioned as plywood & MDF substitutes have been developed & tested successfully.

Two major categories of FRP beam namely, coir-ply boards (jute + rubber wood + coir) as plywood substitute and natural fibre reinforced boards (jute + coir) as MDF substitute have been developed under the project with superior performance, properties and great price advantages. The detailed properties of jute-coir boards tested as per IS-12406 against the specified values of MDF boards are given in Table 3.0.
Detailed evaluation of the jute-coir board samples has been carried out by Indian Railways for their applications as berth backings & partitions in railway coaches; the results conform to the railways' requirements. Based on the initial success of using 500 nos. jute-coir boards as MDF substitute in the railway coaches, the Indian Railways decided to induct 4000 nos. boards.

The industry partner has been offering the technology know-how (hard board grade, MDF grade, plywood grade & doors) for transfer to other industries to enable replication of the benefits accrued. The panel & flush doors made of jute-coir composite boards have also been introduced. These are fast gaining the market acceptance by construction agencies and others.
Energy Efficient Axial Flow FRP Fans

The project aiming at improving fan design to provide optimum efficiency suitable for specific air-flow and system pressure applications was launched in 1998 with technology support from IIT-Bombay, Mumbai. Five types of fans for cooling towers, mine ventilation, textile humidification, radiator cooling for diesel locomotives & air heat-exchangers were developed & tested successfully; an efficiency differential of around 20-30% with commensurate energy saving was achieved over conventional fans with aluminium impellers.

The test results of FRP fans vis-a-vis metallic fans are listed in Table 4.0. These fans promise a pay-back period of 2-3 months at current energy rates. Based on extensive field trials of two radiator cooling FRP fans fitted in diesel locomotives, the Indian Railways have inducted 10 nos. fans for such application.

The energy efficient FRP grating axial flow fans have been inducted for cooling tower, mine ventilation and other applications by leading Indian industries. The axial flow fans enjoy good export potential especially in the neighbouring countries, as there are very few manufacturers of FRP fans, mostly located in Europe and USA.
  FRP Pultruded Profiles

The project aimed at developing FRP Pultruded profiles for industrial gratings, solid rods for electrical insulation, cable trays, ladders etc. These products have been developed successfully with excellent surface finish and flame retardancy as per international standards. The comparison chart of the properties of FRP pultruded sections and other structural materials are listed in table 5.0 & 6.0.
Towards the market seeding for commercialisation of the pultruded product, the Company targeted three major segments viz. new projects, replacement market in industrial & non-industrial applications. Cable trays, gratings, channels & strips & other accessories are being supplied regularly to various industries in India.

from:tifac

Technology incubation has been an international experience in developing and promoting the novel technology applications. The relevance of technology incubation specially assumes importance in the context of a developing economy and industry as typified by India.

From its inception, the Advanced Composites Mission had explored different ways so as to evolve the single most effective mechanism for technology development for faster & wider applications. At the initial stage, the approach had been to locate the incubation activities within the premises of a national level publicly funded R&D lab or an academic institution with the outside support of an industry partner.

The model involved carrying out all the developmental activities and creation of Fiberglass fabric in the laboratory itself supported with major funding from the Mission. The strategy was based on the premise that in the event of successful development of technology, the industry would take it up further for commercialization.

Most of the targeted areas of development were of critical technology without a large usage base, mostly concerning aerospace applications of low-volume but high-value. The strategy lacked in the direct involvement of the users/stake holders (market perspective) in technology development. The industry partners being extraneous to the entire development exercise were not too keen on the outcome. The strategy is schematically illustrated by Fig.

In the later experiment, while the development & incubation activities still centred around the R&D labs, the industry partners were involved directly in die development, prototype fabrication and product testing. The technology incubation became a success with the product finding bulk application.

The case of developing FRP grating for railway girder bridges involving a defence R&D lab, a medium sized entrepreneur and most importantly, the user, Indian Railways, has been successful. The project was co-funded by Indian Railways and the Mission with the promise of large-scale replication.

After a whole gamut of simulated use tests by two national agencies and year-long field trials on actual condition, the FRP sleepers have now been inducted by the Indian Railways. With the knowledge replication, there are four FRP manufacturers in the country today capable of fabricating and supplying the sleepers catering to a large demand pattern. A schematic presentation of the second strategy is given in Fig. 

The most successful strategy of technology incubation has been the latest one wherein the actions were shifted to the premise of SMEs. The SMEs were nurtured with design & technology support from the centres of excellence e.g. IITs, CSIR labs etc. The knowledge partners extended support in terms of design, material selection, process optimization, equipment specifications & procurement, prototype development and finally product testing towards user acceptance.

In all such cases, a tripartite arrangement was arrived at where the centre of excellence, entrepreneur and the Mission worked together. The Mission introduced the unique methodology of project review and monitoring with the involvement of experts mostly drawn from the user agencies.

The technology incubation attributes such as attractive scheme of financial assistance, technological risk sharing, an effective programme management and knowledge-based project monitoring by experts coupled with the market intervention by reaching to the user agencies all helped the Mission to record its achievements in a short span and arrive at a threshold. The Mission functioned more as a ‘facilitator’ than merely a funding agency. The schematic representation of the proven strategy is given in Fig.

Sectors Targeted Towards Technology Development

Under the aforesaid Mission on Advanced Composites, a number of projects on novel composite applications such as Fiberglass mat for railway locomotives, high energy efficiency FRP axial flow fan, pultruded FRP profiles , jute-coir composite boards etc.were initiated in partnership with the industries across the country. There has been an intense interaction with major user agencies from important economic sectors towards product standardization, testing, approval & acceptance for wider induction.

from:tifac

FRP pultruded profiles windows were first produced in Canada in 1984, were subsequently introduced to the USA and European markets and are becoming increasingly popular. Market studies conducted on behalf of North American manufacturers predict a tenfold increase in the next few years. In the UK, pultruded fibreglass windows have been available only since the early 2000s.

Pultruded fibreglass windows offer a number of advantages over other types of window systems, as follows:

> Thermal performance. Pultruded fibreglass has a low coefficient of thermal conductivity that compares favourably with other low conductivity products like PVC or wood. Because of its great strength, profiles can be very thin, thus limiting the potential for cold bridging. Therefore, the thermal performance of the manufactured product is very good.

> Strength. As shown in Table 1, pultruded FRP profiles have greater flexural and tensile strengths than other materials used in fenestration. Therefore, they are suitable for large openings without the need for metal reinforcements.

> Dimensional stability. Pultruded fibreglass has a low coefficient of linear expansion which is very similar to that of glass. Other window materials have much higher coefficients – aluminium’s is double that of glass and PVC’s is seven times greater. As a result, pultruded FRP frames do not distort due to thermal variations.

> Resistance to moisture. Pultruded fibreglass is virtually impervious to moisture, and therefore does not rot, warp, crack or twist.

> Chemical resistance. Pultruded fibreglass is unaffected by chemicals or salt air, and is therefore suitable for coastal locations.

> Appearance. As FRP pultruded profiles are dimensionally and hydroscopically stable, they are a good base for sophisticated finishing systems.

> Cost. Initial capital expenditure is higher than for PVC, aluminium or timber windows. However, a whole life cost study conducted by the Building Research Establishment concluded that over a 30-year period, pultruded FRP was more economical than PVC.

A relatively minor limitation of the product is that FRP profiles cannot be welded, and therefore joints must be formed using adhesives.

Environmental considerations
There are a number of factors to be considered when assessing the environmental impact of pultruded FRP windows, among others:

> Resource depletion. Glass, which is silica based, accounts for approximately 65-85% of the components of FRP profiles. For all intents and purposes, sand can be considered an inexhaustible material. The polymer-based matrix is, of course, subject to the availability of oil for its production.

> Energy during manufacture. Because the main component is silica sand, this is low for FRP profiles .

> Gas release during manufacture. Unlike that of PVC, the manufacture of FRP profiles is a sealed operation, and the release of gases into the atmosphere can be closely controlled.

> Energy used during life. This is generally low, because of the good thermal performance of FRP.

> Disposal. As previously explained, the thermoset resins used in FRP are not easily recyclable, and may, in due course, steer the industry towards the use of thermoplastics.

Pultruded FRP has achieved an A rating in the latest BRE ‘Green Guide to Composites’, which is an environmental profiling system for composite materials and products published by BRE (‘A’ is the highest grade, ‘E’ the lowest). Table 2 compares the environmental impact of pultruded FRP windows with that of two alternatives.

Summary
The use of composites has been embraced wholeheartedly by the sports, aeronautic, car and maritime industries among others, but acceptance by the construction industry has been much more muted. In the UK, the BRE has created a specific forum called the Network Group for Composites in Construction with the aim of disseminating the advantages of composites throughout the building industry. Pultruded fibreglass window profiles, in particular, appear to offer the designer the opportunity of using very slim but strong and durable profiles suitable for large openings without compromising the ‘green’ credentials of the design.

from:ribajournal

Composite materials (composites for short) are engineering materials made up of two or more components which, although remaining separate and distinct, act in unison, each overcoming the deficiencies of the other. Combining the advantages of each element results in a material with broader and more attractive properties than its individual components. One of the two constituents acts as reinforcement and it is surrounded by the other, a matrix which transfers loads to it.

A very early example of composites is the use of mud bricks, with straw acting as reinforcement.

Reinforced concrete is a more modern example, where the poor compressive strength of steel is made up by the good performance of the concrete, with the opposite being true for tensile strength. Reinforcement materials used can be present in the form of particulates, discontinuous fibres (short fibres) or continuous fibres. Matrix products include metals, ceramics and plastics.

This overview of composites applied to windows will focus on glass fibre reinforced plastics (FRP grating ), where the matrix is a polymer and the reinforcement is carbon, glass or aramid fibres. Aramid is a synthetic long chain polyamide best known by its trade name Kevlar, used in the construction of bullet-proof vests. These reinforcement materials have very high tensile and compressive strengths, but in their natural form fail at levels lower than their theoretical limits because of surface flaws that cause them to crack. When the material is used in fibre form, these surface flaws are limited to a small number of fibres, whereas the remainder still behave to their theoretical limits.

The function of the matrix is to spread the load to the individual fibres, and also to protect them from damage resulting from abrasion and impact. Materials used for the matrix can be categorised as:
> Thermoset polymers, which are plastic resins that cure by chemical reaction when heated and, once cured, cannot be resoftened by heating. Their greatest advantage is that, because of their low viscosity, fibre impregnation can be carried out at low pressure. More than 90% of the polymers currently being used in composites are thermoset.

> Thermoplastic polymers, which are plastics capable of being repeatedly softened by increases in temperature and hardened by decreases in temperature. They are also tougher and FRP applications than thermosets, but are more expensive to process as this must be done at a much higher pressure. However, they are much more readily recyclable than thermosets and, in the future, this may swing the choice their way in spite of the additional costs. A recent innovation has been the development of a proprietary patented product consisting of fibreglass reinforcement fibres in a PVC-U matrix, which is a thermoplastic polymer.

Various polymers are currently used as the matrix constituent, including: polyester resin; vinyl ester resin; epoxy; polyimide; polypropylene, etc.

The properties of a composite are determined by:

> the properties of the reinforcement

> the properties of the matrix

> the ratio of fibre to matrix (called fibre volume fraction). This is adjusted accurately during the impregnation process to suit the intended product use and ensure an even distribution. Although, in theory, a very high FRP profiles volume fraction would result in higher mechanical properties, there is a practical limit because all fibres need to be fully impregnated.

> the geometry and orientation of the fibre in the composite. The diameter of the fibre is of great importance, as finer fibres have proportionally a larger surface area, and therefore the loads transferred by the matrix are spread more efficiently. Composites have anisotropic properties, ie, properties that are direction-specific as a result of the orientation of the fibres.

In the construction industry, pre-impregnated materials, ie, materials where the reinforcement has been pre-impregnated with resin before forming are the most commonly used ones, as opposed to those where the reinforcement is added to the matrix at the moulding stage. There are two basic types of pre-impregnated FRPs:

> unidirectional, where the impregnated fibres are aligned in one direction only and

> woven, which is a resin-impregnated fabric.

The composite must then be formed in the required shape/profile, generally by moulding. Until recently, this has necessitated high temperature and/or pressure, with associated high costs. However, the advent of low temperature moulding materials has simplified the process and lowered costs allowing possible on-site processing without the need for autoclaves and manufacturing shops.

The very high strength-to-weight ratio of composite materials makes them very suitable for structural long span applications, and their flexibility allows complex shapes to be formed, for example, lightweight cladding panels. Durability is also high, and life cycle and maintenance costs are low.

Fiberglass mat
Since its invention in 1938, fibreglass reinforced plastic (FRP) also known as GRP (glass reinforced plastic) has grown in popularity and now accounts for approximately 65% of composite production.

Fibreglass fibres are extruded molten glass (usually silica based, but not exclusively so) fibres, braided into bundles to form a continuous rope. FRP is produced by combining a polymer matrix with fibreglass reinforcements, either cut into short strands or woven into a cloth. The ratio between matrix and reinforcement is generally 65-85% resin and 15-35% reinforcement. All FRP products are thermosets.

Different grades of Fiberglass fabric can be produced by varying the composition of the glass used for the fibres, for example:

> E-Glass, which has good electrical properties

> C-Glass, offering the best resistance to chemical attack, etc

> R-, S- or T-Glass are not grades, they simply refer to proprietary trade names from various manufacturers.

When the FRP has been woven into a cloth, it is then moulded into shape. There are various moulding techniques, including open moulding, which produces only one good, finished surface and a rough one, and autoclave and vacuum moulding, which produce two finished surfaces. However,FRP pultruded profiles can also be formed into continuous profiles by means of a process called pultrusion.

In the extrusion process, the material to be formed is pushed through a die, but fibre-reinforced composites need to be pulled instead. This process is called pultrusion (the name is a portmanteau word derived from the words ‘pull’ and ‘extrusion’).

Figure 1 explains the pultrusion process in schematic form: the reinforcement fibres are pulled through a resin bath, where they are impregnated, through a forming plate that confers the composite its profile section and then finally into a heated die where the resin is polymerised. As it cools down, the profile solidifies and is eventually cut into the required lengths.

The process of pultrusion has several advantages:

> it is a fast, economic way of impregnating and curing materials

> volatile emissions can be limited because resin impregnation takes place in enclosed surroundings

> resin and fibre content can be accurately controlled

> structural properties of laminates can be good since the profiles have very straight fibres and high fibre volume fractions can be obtained.

An even more recent development is the process of co-pultrusion, where two or more materials pass through a single die, and the resulting product is a laminate profile, where each ply of the laminate confers to it a desired property (for example, resistance to some specific environment, stiffness, etc).

Pultruded fibreglass products are very strong, dimensionally stable and durable, and can be formed accurately into sophisticated profiles. It is therefore not surprising that they are now increasingly being used in the manufacture of windows and doors. Table 1 compares the mechanical and physical properties of pultruded profiles with those of other materials.

from:ribajournal

The project on 'Development of FRP Pultruded Profiles' was launched under the Advanced Composites Mission of TIFAC in August 1998 in partnership with M/s. Sucro Filters Ltd., Pune with technology support from National Chemical Laboratory, Pune. Sucro Filters has been working on pultrusion process, pultruded profiles and development of pultrusion dies with the NCL since January, 1998.

NCL support towards pultrusion die design, optimization of process parameters, resin formulation, selection of catalyst combinations in the resin etc. helped achieve a high pultrusion speed of 1.0-1.5 m/min with improved curing. Flame retardancy characteristics as per UL94V0 was achieved using halogenated resin & ATH (aluminium trihydrate) combination in pultruded FRP profiles.

The pultruded profiles like I-beams, channels, angles, flat strips, notch bars for FRP grating , cable-trays & ladders and solid rods for electrical insulation, etc. developed under the project were tested for mechanical & physical properties. The properties compared very favourably with the internationally available products.
Pultrusion is the most cost-effective method for the production of fibre-reinforced composite structural profiles. It brings high performance composites down to commercial products such as light-weight corrosion free structures, electrical non-conductive systems, off-shore platforms and many other innovative new products.

Based on the success of initial pultrusion trials at NCL, an associate Company, M/s. D K Fibre Forms Ltd. (DKFFL), Pune was promoted by Sucro Filters towards diversifying into the business of pultruded products. D K Fibre Forms has already set up quite a sophisticated pultrusion equipment & stabilized the process. A tool room equipped with radial drilling machine, plano milling machine & surface grinding machine and allied testing facilities for fabrication of pultrusion dies has been created at Sucro Filters with the assistance from TIFAC.

Towards the market seeding for commercialisation of the pultruded product , the Company targeted three major segments viz. new projects, replacement market in industrial & non-industrial applications. The orders for gratings for Alfa Laval, High Explosives Factory, Thermax Ltd., Pudamjee Pulp & Paper Mills etc. and also for railway coach interiors for the Integral Coach Factory, Chennai have been executed. Various applications & usage of the product have been actively pursued and the product has been recognized by acclaimed consulting agencies such as Humphrey & Glasgow, Uhde, Tata, EIL, Bechtel etc. DKFFL has recently bagged an order for supplying cable trays, fittings & other accessories to M/s Dabhol Power Project (DPP) as per the specifications of M/s Bechtel International Inc., the prime consultant for DPP.

The amount of energy required for fabricating FRP composite materials for structural applications with respect to conventional materials such as steel & aluminium is lower and would work for its economic advantage in the end.

from:tifac

The FRP Pultruded grating is a kind of plank with interstice, made into “H”-section profiles and “T”- section profiles. They are used as bearing bar and connected by zigzag connection rod according. It has a lot of advantages, such as less weight and higher strength, antisepsis, antiskid, combating ageing, long usage lifetime, resisting plane and fragmentation. In its creation, fire is not used, and the FRP Pultruded is dielectric and is not electrostatic. At the same time, in real usage, it doesn’t produce scintilla for impact. It is convenient to incise and install, and it has higher comprehensive benefit.

   Pultruded FRP grating is widely used in operation platforms, equipment platforms, stair steps, ditch covers, walkways, filter plates and filler supports, etc. in petroleum, chemistry, power, offshore exploration, electroplating, watercraft, water and waste water treatment, paper production, brewery and pharmacy industries. They are the ideal bearing parts in corrosive environment.

Because FRP is a composite material, its properties to adapt to a wide range, so it's very broad prospects for market development. According to relevant statistics, at present developing countries in the world the type of glass steel products reached about 40,000 kinds. While countries are in accordance with national economic development, the development of the direction of their different focuses, but basically have been involved in various industrial sectors. China's steel industry through the glass 40 years of development, has also been in the national economy has achieved success in various areas of application, in economic development has played an important role.

FRP now the main application areas, roughly summarized as follows:
@ the construction industry: cooling towers, FRP doors and windows New, building structure, envelope, interior equipment and decorative pieces of glass, steel plate, wave tile, decorative panels, sanitary ware and the overall bathroom, sauna room, surfing the bathroom, construction template, store construction, as well as the utilization of solar energy devices and so on.

@ Chemistry and Chemical industry: corrosion-resistant pipes, storage tanks storage tanks, corrosion-resistant pumps and its accessories, corrosion-resistant valves, grilles, ventilation facilities, and sewage and wastewater treatment equipment and accessories and so on.

@ Cars and rail transport industries: Automotive shell and other parts, all plastic mini-cars, large passenger body shell, doors, inner panels, the main columns, floors, bottom beams, bumper, instrument panel, mini-vans, as well as fire tankers, refrigerated trucks, tractor cab and machinery enclosures, etc.; in railway transport, a train window frames, inside the top bending plate, roof water tanks, toilet floor, luggage cart doors, roof ventilators, refrigeration door , storage tanks, and some railway communication facilities, etc.; in highway construction, there are traffic signs, road signs, Geli Dun, highway guardrail and so on.

@ Boats and water transport industry: River packet boat, fishing boats and hovercraft, all kinds of yachts, rowing, high-speed boats, lifeboats, transport boats, as well as glass, steel drums and floating buoy mooring buoy and so on.

@ Electric Industrial and Communications Engineering: There interrupter devices, cable protection pipes, generator stator coils and the supporting ring and the cone shell, insulation pipe, insulation rod, motor retaining ring, high-voltage insulators, standard capacitor casing, motor cooling casing, Strong wind generators and other electrical equipment panels; distribution boxes and electrical panels, insulated shaft, glass, steel enclosures and other electrical equipment; printed circuit board, antenna, radome and other electronic engineering applications. In recent years, with the scientific and technological development, as well as the improvement of people's living standards, many civilian glass fiber reinforced plastic products has been developed, such as the number of urban sculpture, arts and crafts style, fast food furniture, motorcycle parts, glass fiber reinforced plastic flower pots, safety helmets, Senior play equipment, household appliances, shell, etc., have successfully been widely applied.

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 the order of 0.05 W/(m·K).

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. Humidity is an important factor in the tensile strength. Moisture is easily adsorbed, and can worsen microscopic cracks and surface defects, and lessen tenacity.

In contrast to carbon 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 (GRP) is a composite material or fiber-reinforced plastic made of a plastic 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 plastics are normally used for GRP production—most often unsaturated polyester (using 2-butanone peroxide aka MEK peroxide as a catalyst), but vinylester or epoxy 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 concrete), the two materials act together, each overcoming the deficits of the other. Whereas the plastic resins are strong in compressive loading and relatively weak in tensile strength, 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 for regular fiberglass include fiberglass mats , thermal insulation, electrical insulation, 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, surfboards, boat hulls, and paper honeycomb. It has been used for medical purposes in casts. Fiberglass is extensively used for making FRP grating and vessels. Fiberglass is also used in the design of Irish stepdance shoes.

Manufacturers of fiberglass insulation can use recycled glass. Owens Corning's fiberglass has 40% recycled glass. A recycling program begun in 2009 in Kansas City, Kansas, will ship crushed recycled glass, called cullet, to the Owens Corning plant that will use it as raw material for fiberglass making.

from:wiki

The basis of textile-grade glass fibers is silica, SiO2. In its pure form it exists as a polymer, (SiO2)n. It has no true melting point but softens at 2,000 °C (3,630 °F), where it starts to degrade. At 1,713 °C (3,115 °F), 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 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 1,200 °C (2,190 °F) for long periods of time.
Molecular Structure of Glass

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. It was not very resistant to alkali. A new type, E-glass, was formed; this is an alumino-borosilicate glass that is alkali free (<2%).

This was the first glass formulation used for continuous filament formation. E-glass still makes up most of the Fiberglass mat , Fiberglass fabric 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. 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 solubility in water but are very dependent on pH. Chloride 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 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.

from:wiki

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 invention 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. This was first worn by the popular stage actress of the time Georgia Cayvan.

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. It is marketed under the trade name Fiberglas, which has become a genericized trademark. A somewhat similar, but more expensive technology used for applications requiring very high strength and low weight is the use of carbon fiber.

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 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 staple (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).

Properties
• Fiber level unfolded without cross, high density, high utilizing rate.
• Multi-layer finished one time, decrease layer and enhance efficiency.
• Providing the product with multi-directional mechanical strength.

Applications
Mainly be used as reinforced materials in the composite material industry.
• Matrix: unsaturated polyester resin, vinyl ester resin, epoxy resin and phenolic resin etc.
• Craft: pultrusion, RTM, hand lay up, etc.
• Ultimate products: pultruded profiles , FRP body of boat, insulation board, automobile body. 

from:jdfrp|FRP

FRP grating is manufactured by combining a matrix of resin and fiberglass. That makes it a composite material. FRP grating does not corrode like steel gratings. That is what gives them there value. They are used in corrosive environments. They lower maintenance costs.

Molded Grating is made on a mold. Pultruded Grating made by joining pultruded profiles in to the shape of a grating.Many resin types may be used in pultrusion including polyester, polyurethane, vinylester and epoxy.

Process
Molded gratings are panels with systematic void. They combine the mosetting resins (include some unsaturted polyester resin, vinyl resin, phenolic resin) as matrix with fiberglass rovings etc as reinforced material.. They are formed by overall demoulding after interlaced solidification in a large metal die.

Properties
Corrosion resistance
Light weight
High load capacity-load capacity 
Nonslip
Flame retardancy
Impact resistance and anti-fatigue
Electric insulation& non-magnetic
Anti-aging
Good appearance & easy to maintain
Operate easily 

Applications 
FRP molded gratings are often used in the fields of petrochemical industry, textile printing and dyeing, , food processing, electronics industry, pharmaceutical manufacturing, power engineering, metal smelting, sewage treatment, transportation, water plant breeding, pulp and paper, shipbuilding, civil architecture etc. The concrete uses include operating platform, overhauling walkways, drilling platform, terrace, stair steps, equipment aisle, trench cover, boat deck, ventilation grid, fence etc.

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 materials. Certain types of foam are commonly used.

After the plug has been formed, it is sprayed with a mold release agent. The release agent will allow the mold to be separated from the plug once it is finished. The mold release agent is a special wax, and/or PVA (Polyvinyl alcohol). Polyvinyl Alcohol, however, is said to have negative effects on the final mold's surface finish.

Once the plug has its release agent applied, gelcoat is applied with a roller, brush or specially-designed spray gun. The gelcoat is pigmented resin, and gives the mold surface a harder, more durable finish.

Once the release agent and gelcoat are applied, layers of fiberglass and resin are laid-up onto the surface. The fiberglass used will typically be identical to that which will be used in the final product.

In the laying-up process, a layer of fiberglass mat is applied, and resin is applied over it. A special roller is then used to remove air bubbles. If left in the curing resin, air bubbles would significantly reduce the strength of the finished mold. The fiberglass spray lay-up process is also used to produce molds, and can provide good filling of corners and cavities where a glass mat or weave may prove to be too stiff.

Once the final layers of fiberglass mat are applied to the mould, the resin is allowed to set-up and cure. Wedges are then driven between the plug and the mold in order to separate the two.

Advanced techniques such as Resin Transfer Molding are also used.