Fiberglass Molding

Fiberglass molding is a method for forming complex and intricate parts using fiberglass resin. Though there are several reasons for producing parts and components from fiberglass, the most pressing reasons are the...
Please fill out the following form to submit a Request for Quote to any of the following companies listed on
This article will take an in-depth look at fiberglass sheets.
You will understand more about topics such as:
Fiberglass is a plastic reinforced material where glass fiber is used as reinforcement, and the glass fiber is flattened into a sheet. It is also known as glass fiber reinforced plastic or glass reinforced plastic. It is made of the same glass used to make windows; however, the manufacturing method gives it its form. The glass is melted and forced through holes that are very tiny and small in diameter. This process produces very thin filaments and can be woven into sheets. Its thickness varies from 1.5mm to 75mm.
It is composed of glass fibers implanted in a resin matrix. The basic composition of all fiberglass types is almost the same. Only a few raw materials differ in quantities and proportion for each type to suit their specific uses. So, each type has a different composition that makes it suitable for its specified application. The basic raw materials used in fiberglass sheets manufacturing include silica sand, soda ash, and limestone. Other ingredients include borax, calcined alumina, magnesite, kaolin clay, and feldspar among others. Silica sand is the glass former and soda ash and limestone lower the melting point during the manufacturing process. Other ingredients can improve some characteristics, such as borax which improves chemical resistance.
To create fiberglass, different raw materials such as (silica, sand, limestone, kaolin clay, and dolomite) are melted in a furnace until they reach a melting point. The melted glass is then extruded through tiny brushings or spinnerets to produce tiny extrusions called filaments. These filaments are of two common types that are continuous filaments and staple filaments. The filaments are then sized (coated in a chemical finish) and bundled into rovings. The number and quantity of the filaments in a roving and how thick the individual filaments are determine the weight of the glass fibers, which is typically expressed in yield.
The initial stage of fiberglass manufacture is called batching. This is when raw materials are prepared to be fed into the furnace. In this stage, raw materials must be carefully weighed in exact quantities and thoroughly mixed (batched). Due to increased technology batching has become automated, using computerized weighing units and enclosed material transport systems.
The batch is fed into the furnace, after it is prepared, where it will melt. The raw materials are fed into the furnace to begin the melting process. Electricity, fossil fuel, or a combination of the two can be used to heat the furnace. The temperature must be precisely controlled to maintain a smooth, steady flow of the molten glass.
The furnace is typically divided into three sections, with channels and aid glass flow. The furnace’s first section is where the batch is first fed, melted, increased in uniformity and removal of bubbles. The molten glass then flows into the refiner, where it is cooled, and its temperature is reduced. The final section is the fire hearth, beneath which is located a series of four to seven bushings used to extrude the molten glass into fibers.
After melting, the next stage is fiberization. In this stage the molten glass forms into fibers. Glass fiber formation or fiberization involves a combination of extrusion and attenuation. In extrusion, the molten glass passes out of the fire hearth through a bushing made of an erosion-resistant platinum/rhodium alloy with very fine orifices. The filaments are cooled by the water jets as they exit.
The molten glass extruded streams are mechanically drawn through attenuation into filaments. They have a diameter that ranges from 4-34 micrometers. A high-speed winder catches the molten streams and, because it revolves at a high speed, tension is applied, drawing them into thin filaments. Several different processes are used to form fibers depending on the type of fiber, with the main types being the continuous filament and the staple fiber process.
This process can yield a long, continuous fiber. Fiberglass filaments of indefinite length are produced through this process. As the glass flows through the bushing holes, the high-speed winder catches several strands. The strands of fiberglass produced are carried to the winder that revolves at a very high speed. A continuous fiberglass filaments yarn is thus obtained at the end of the process.
Long glass fibers are produced through the staple fiber process. As the molten bulk passes through small openings, a jet of compressed air converts the streams of molten bulk into long and thin fibers. The fibers gather to form a sliver. From the sliver, yarn of fiberglass is made that is then used for insulation purposes in different industries.
Chemical coating is the last and final stage where a chemical coating or size is applied. The size can range between 0.5 to 2.0% by weight, including binders, lubricants and/or coupling agents. Abrading filaments can be mitigated by using lubricants, which also minimize breaking at the collection and wounding into forming packages. They can later be processed into fabrics using weavers and other converters. The coupling agents aid the fiber to be attracted to a specific resin chemistry. This strengthens the interface of the fiber and matrix adhesive bond and improves the resin wet out. Depending on the size of the chemistries, some can be more compatible with epoxy and some with polyester resin. Fiber abrasion can be reduced by applying lubricants by either adding them into the binder or spraying directly on the fiber. During the cooling phase, an anti-static agent can be sprayed onto the fiberglass insulation mat surface. The anti-static composition penetrates the mat’s thickness via the cooling air. Generally, two ingredients make up the anti-static agent i.e. a stabilizer or corrosion inhibitor and a material to minimize static electricity generation.
The fiberglass products use various processes which bring about several shapes. As an example, mandrels can be formed from winding fiberglass pipe insulation prior to curing. The mold forms that are 3 feet or less in length are oven cured. After oven curing, they are de-molded along their length and are then sewn into different orientations. In some cases, facings are applied then the final product is packaged for shipping.
This chapter will discuss properties of fiberglass and properties of reinforced composites.
Fiberglass has properties that make it a good choice in various applications. It also poses benefits when reinforced composites are made with glass strands. Firstly, the properties of fiberglass are detailed below.
The properties of fiberglass include:
The mechanical properties of fiberglass sheets are very favorable. Fiberglass has a specific resistance that is greater than steel wire of the same diameter at a lower weight. Its rebar has a higher longitudinal tensile strength, and lower modulus of elasticity and density in contrast with steel. Fiberglass is stiff and has high compressional and tensile strength along its axis. These characteristics are the main reason why fiberglass is used to produce composites of high performance.
Fiberglass is regarded to be good at insulation, even with thinner layers. The combination of properties like low moisture absorption, high dielectric strength and a low dielectric constant makes it the ideal insulation material.
Fiberglass is not combustible since it is a mineral material. It has high heat resistance. Fiberglass does not support or propagate flames and if exposed to heat, it does not emit toxic products or smoke. It does not burn and is basically unaffected by curing temperatures used in industrial processing. Fiberglass will retain approximately 50% of its strength at extremely high temperatures.
Fiberglass is highly resistant to the attack of most chemicals, and it is also resistant to corrosion.
Fiberglass is a dimensionally stable engineering material. It has no sensitivity to changes in temperature and hygrometry, making it very stable. It does not warp, bend, distort or shrink after exposure to extremely high or low temperatures as it has a low coefficient of linear expansion.
Fiberglass can have different types of sizes, which creates a bond between the glass and the matrix and can combine with many synthetic resins and certain mineral matrices like cement and plaster.
The low thermal conductivity of fiberglass makes it very useful in the industry. This is because the use of glass strands composites eliminates thermal bridging, enabling considerable heat savings compared to asbestos and organic fibers. Fiberglass is a great thermal insulator because of its high ratio of surface area to weight.
Fiberglass maintains its form and is not impacted by the action of rodents and insects. It also does not rot, and it is not affected by most chemicals and weather because it does not decompose.
When exposed to water, fiberglass does not change in form. It does not absorb moisture hence it will remain unchanged physically and chemically.
When composites are reinforced using glass strands, the characteristics exhibited include:
Various technical methods can be used to recycle glass strands. This is akin to recycling glass reinforced parts made from thermoset or thermoplastic.
Up to 30% of weight can be shed off when reinforced plastic is used in place of steel. The reinforced plastic parts can still maintain properties like thermo-mechanic parts.
Composites facilitate the making of a part with multiple functions. For example, in motor vehicles, complex shapes, dimensional accuracy, lightweight, reliability and valuable thermo-mechanical characteristics can be merged into a composite.
Mats and tissues that are used in glass reinforcements aid in enhancing surface finish when molded or added to other materials. This is because through the use of resins, they permit uniform impregnation. They are less prone to splitting, cracking, or breaking.
The use of glass strands helps in reinforcing multiple sized parts of different shapes. The parts could include pipes, vessels, electrical components, electrical cables, inlet manifolds, etc.
Glass strands and composite parts exhibit superior compression strength, tensile strength, moisture absorption, and resistance to corrosion, cracking, abrasion, and breaking.
Various proportions of different raw materials can be used to form fiberglass. The fiberglass formed can be categorized into the following types:
A-glass is also known as alkali glass or soda-lime glass and is resistant to chemicals. It is the most commonly available type of fiberglass and mostly It is used in making glass containers like jars and bottles for food and beverages and window panes. Soda-lime is much cheaper, chemically stable, hard, and workable. Soda-lime can be remelted and softened and thus best suited for glass recycling.
The A-glass type is made primarily from lime, soda, alumina, dolomite, silica, and finishing agents like sodium sulfate. A-glass fiber can be found as:
Flat glass - is used to make windows. A float process is used in forming flat glass. It has a higher quantity of magnesium oxide and sodium oxide and a lower quantity of silica, aluminum oxide, and calcium oxide as compared to container glass.
Container glass - is typically used to make containers. It is manufactured by blowing and pressing. Container glass is more chemically durable in containers used for food and beverage storage due to its low content of water-soluble ions such as sodium and magnesium.
Advantex glass is acid corrosion resistant. It can be used in applications where thermal fluctuation is greater due to its higher melting point. Advantex fiberglass contains calcium oxide in high quantities and is typically used in structures that are corrosion prone. Moreover, Advantex glass can be applied in the oil industry, mining industry, sewage systems, and power plants.
This is alkali resistant glass.
AR-glass is also known as alkali resistant glass. It is specifically designed for use in concrete. This is enabled by Zirconia which is added into the AR-glass structure and thus the fiberglass can be applied in concrete. When used in concrete, AR-glass prevents cracking thereby providing flexibility and strength to the concrete. AR-glass is not easily dissolvable in water and is generally unaffected by pH changes. AR-glass does not rust and can be easily added to steel mixtures and concrete.
The C-glass type is also called chemical glass and has good chemical impact resistance. The C-glass gives structural equilibrium when subjected to corrosive environments. This is facilitated by calcium borosilicate in high quantities. A-glass type chemicals used in its manufacturing have pH values that give high resistance to C-glass regardless of whether the environment is alkaline or acidic. The C-glass can thus be applied as surface tissue in the outer layer laminates of tanks and pipes used to hold chemicals and water.
Ingredient | % Composition |
---|---|
Silica | 62 to 65 |
Soda, Potash | 1.0 |
Lime | 6 |
Boric Oxide | 3 to 4 |
Magnesia | 1.0 to 3.0 |
Alumina | 11 to 15 |
D-glass is popular for being a low dielectric constant. This is facilitated by boron trioxide presence in its structure. The D-glass type of fiberglass is typically used in optical cables, cookware, and electrical appliances.
E-glass is also known as electrical glass and has good electrical insulation properties. It is an alkali glass. It is susceptible to chloride ion and cannot be used for marine applications. It is a lightweight composite material that is used in aerospace and industrial applications. E-glass is much cleaner to work with due to its draping characteristic. It was originally developed to be used in electrical applications, but it is now used in numerous other areas as well. Glass reinforced plastic can also be made with a combination of thermosetting resins. The glass reinforced plastic can then be used to make panels and sheets, which are applied in a wide range of industries. Structural integrity can be protected against any mechanical impact.
E-glass is very popular across industries because it has high strength, is cheaper, nonflammable, high stiffness, is not moisture sensitive, low density, electrical insulation, resistant to heat, and can maintain strength in various conditions.
Ingredient | % Composition |
---|---|
Silica | 52.5 to 53.5 |
Soda, Potash | Less than 1.0 |
Lime | 16.5 to 17.5 |
Boric Oxide | 10.0 to 10.6 |
Magnesia | 4.5 to 5.5 |
Alumina | 14.5 |
ECR glass fiber is also known as electronic glass fiber. It has acid and alkali resistance, waterproof properties, high heat resistance, lower electrical leakage, higher surface resistance, and mechanical strength when compared to E-glass. Its properties are generally better than E-glass properties. Unlike many other types of fiberglass, the ECR glass manufacturing process is environmentally friendly. ECR glass fiber is used to make transparent fiberglass reinforced panels with a longer service life. ECR glass has superior resistance to acid, water, and alkali and thus is more durable.
The same fiberglass can be known as R-glass, S-glass, and T-glass. Their modulus, acidic strength, wetting properties, and tensile strength is superior to that of E-glass. R-glass can be applied in the aerospace and defense industries. It is a high-performance and industry specific fiberglass produced in low volumes.
S-glass is also known as structural glass. It is popular for its mechanical properties, which include stiffness. S-glass is mostly useful when tensile strength is a critical consideration. Thus, S-glass is typically used in aircraft and building epoxies.
This is the best performing fiberglass type available. Silica can be found in higher levels in S2-glass, unlike in other fiberglass types. Thus, S2-glass has improved properties like high compressive strength, high temperature resistance, better cost performance, and high impact resistance. Due to its superiority in properties over conventional fiberglass types, S2-glass is typically used in the textile and composite industry.
Z-glass can be used in various industries, such as the concrete reinforcement industry, where it is used to create transparent products. Z-glass can be used in creating 3D printed fibers. Z-glass is reliable and durable due to its high acid, alkali, UV, mechanical, scratch, salt, and wear resistance.
This chapter will discuss applications and uses of fiberglass.
Fiberglass comes in various forms to suit various applications, the major ones being:
The fiberglass tapes are popular for their thermal insulation properties and are made from glass fiber yarns. The fiberglass tape is applied widely in applications such as hot pipelines, wrapping vessels etc.
The fiberglass cloth can exist as glass filament yarns and glass fiber yarns. Fiberglass cloth is typically used to shield heat in materials such as fire curtains.
Fiberglass ropes are typically used in packing applications and are made from glass fiber yarns.
Applications of fiberglass sheets across industries include:
The aircraft and aerospace industry require material that is lightweight and stable. S glass is the most used in this industry because of its favorable mechanical properties like high strength, high laminate strength to weight ratio. It also has the highest retention at high temperatures. It is mostly used to make wings, helicopter rotor blades, aircraft armor, flight deck armor, floors, and seats of aircraft. S-glass has no conductivity hence it offers lower radar thermal profiles, it allows the military to see without being seen.
Fiberglass has mechanical properties that are even better than those of conventional construction materials making it suitable for the construction industry. It has less weight, is inflammable, has impact resistance, and has high strength, these are all the properties that any construction material should have, and fiberglass has all of them. Fiberglass is used in the construction of commercial, residential, and industrial constructions, ranging from bathroom fixtures to swimming pool fences to skylights of industrial buildings to solar heating elements. Glass-reinforced plastics or fiberglass sheets are also used to produce house building components such as roofing laminate, roofing sheets, door surrounds, over-door canopies, window canopies and dormers, chimneys, and windows.
In consumer goods, fiberglass can be used to make furniture frames and/or finished goods such as divider screens, decorative trays, wall plaques, sports equipment, playground equipment, etc. It is used as a primary material in these consumer goods because of its higher strength, lightweight, formability, durability, resistance to wear, and corrosion.
Fiberglass is the best material to make equipment or machinery which has to be resistant to corrosion. Some items have to be resistant to corrosion because they will be exposed to unfavorable and harsh environments so fiberglass is the best material to be used in the manufacture of these tanks so that they can last longer. Thus, fiberglass can be used in the energy production industry to make corrosion resistant equipment like underground petrol tanks, storage tanks, cooling towers, drainage, water pipes, etc.
Due to its favorable mechanical strength and temperature stability, fiberglass is the perfect material for electrical applications. It is also used as an insulator in industries to insulate electrical equipment. Fiberglass coatings are thus used to insulate wirings. Fiberglass is also used in switchgear, transformers, distribution-pole hardware, computer and cellphone parts, and many more. It is also used in power generation because it is non-conductive.
Fiberglass is commonly used in the marine industry due to its durability and strength. One of the major pros of using fiberglass in the marine industry is that it can be molded into different shapes easily. Thus, fiberglass can be used widely. It is used to make boats of all sizes and other equipment used in the marine. It is also used in the production of docks. Docks get corroded, rusted, and damaged by the salty seawater, so fiberglass is used here for protection.
Polymer matrix composites containing glass fibers are used to make numerous structural car parts and components like bumper beams, belts in a belted bias tire and engine components. The light-weightiness of fiberglass has made it a preferred material in the automobile industry. Fiberglass is also used to make railway fishplates.
This chapter will discuss disadvantages and advantages of fiberglass sheet as well as considerations when selecting fiberglass sheet.
Fiberglass sheets may have drawbacks which include:
However, the advantages of fiberglass sheets outweigh the drawbacks. These advantages include:
Before choosing the type of fiberglass, first consider the type of project and the needs of the finished product. Things to consider are damage tolerance, mechanical and physical properties that are favorable for the project in question. Make sure to also consider cost. After this, compare the findings with other alternative materials and select the most suitable one.
Fiberglass molding is a method for forming complex and intricate parts using fiberglass resin. Though there are several reasons for producing parts and components from fiberglass, the most pressing reasons are the...
Plastic fabrication is the process of designing, manufacturing, and assembling a product made out of plastic material or composites that contain plastic. There are numerous plastic fabrication methods known today, considering the wide variety of products made out of plastic...
Plastic injection molding, or commonly referred to as injection molding, is a manufacturing process used in the mass fabrication of plastic parts. It involves an injection of molten plastic material into the mold where it cools and...
Plastic materials are objects artificially made from organic compounds called polymers along with other additive components. They possess excellent formability, making them extremely versatile for many different fabrication and manufacturing processes...
Polyurethane molding is the process of fabricating or manufacturing plastic parts by introducing a urethane polymer system into a tool or mold and allowing it to cure. Like any other type of plastic, the excellent processability...
Polyurethane rollers are cylindrical rollers covered by a layer of elastomer material called polyurethane. Depending on the application, the inner roller core is prone to scratches, dents, corrosion, and other types of damage...
Thermoplastic molding is a manufacturing process that works to create fully functional parts by injecting plastic resin into a pre-made mold. Thermoplastic polymers are more widely used than thermosetting...
Urethane casting is the process of injecting polyurethane and additive resins into a soft mold usually made of silicone elastomer. The casting process is similar to injection molding; injection molding differs by using hard, metal molds...
Urethane wheels are wheels made of molded urethane, also known as polyurethane. Urethane is an elastomer that comprises urethane carbamate linkages and is a portmanteau phrase for elastic polymer...