What Is Fiberglass?
Fiberglass is a composite material that’s made of very fine glass fibers. You’ll also find it going by the names glass-reinforced plastic and glass fiber plastic.
This is slightly misleading as fiberglass isn’t a pure plastic, but rather one that’s reinforced with the aforementioned tiny glass fibers.
Woven together, these glass fibers are ultra-strong and can be used as an insulation or coating or used all on its own as a material. You can usually see the small fibers when looking up close at an item made of fiberglass.
It’s usually clear or slightly opaque with a white tone. That said, manufacturers can dye and coat it. You’ve probably come across tan-colored belts, materials, and tapes or fiberglass products that are black, gray, white, or various other shades.
Fiberglass is a lot older than you probably would think. It’s not a recent development nor did it come about in the Industrial Revolution it goes much further back.
Ancient civilizations, including the Phoenicians and Egyptians were actually the first to develop a fiberglass of sorts.
This was much rougher and rudimental than what’s used today, but it was a similar material and used mostly for decoration.
In the late 19th century, fiberglass got an upgrade. John Player came onto the scene and thought up a process that used steam jets to turn glass into weavable fibers.
Other developments were made with fiberglass fabrics. But it wasn’t until the 1930s that researcher Dale Kleist concocted the material that’s most familiar to us now.
Kleist accidentally created fiberglass when welding glass blocks together, which the company Corning Glass picked up on.
From then on, fiberglass was continually improved, and eventually, it became an extremely popular choice for product manufacturing.
How Fiberglass is Made?
Fiberglass really is made of glass similar to that in windows or kitchen drinking glasses. To manufacture fiberglass, glass is heated until molten, then forced through superfine holes.
This creates glass filaments that are extremely thin so thin, in fact, that they’re best measured in microns.
These flexible filament threads can be used in several applications: They can be woven into larger swatches of material or left in a somewhat less structured form used for the more familiar puffy texture used for insulation or soundproofing.
The final application is dependent on the length of the extruded strands (longer or shorter) and the quality of the fiberglass.
For some applications, it’s important that the glass fibers have fewer impurities, however, this involves additional steps in the manufacturing process.
Construction methods.
Filament winding.
Filament winding is a fabrication technique mainly used for manufacturing open (cylinders) or closed-end structures (pressure vessels or tanks). The process involves winding filaments under tension over a male mandrel.
The mandrel rotates while a wind eye on a carriage moves horizontally, laying down fibers in the desired pattern. The most common filaments are carbon or glass fiber and are coated with synthetic resin as they are wound.
Once the mandrel is completely covered to the desired thickness, the resin is cured; often the mandrel is placed in an oven to achieve this, though sometimes radiant heaters are used with the mandrel still turning in the machine.
Once the resin has cured, the mandrel is removed, leaving the hollow final product.
For some products such as gas bottles, the ‘mandrel’ is a permanent part of the finished product forming a liner to prevent gas leakage or as a barrier to protect the composite from the fluid to be stored.
Filament winding is well suited to automation, and there are many applications, such as pipe and small pressure vessels that are wound and cured without any human intervention.
The controlled variables for winding are fiber type, resin content, wind angle, tow or bandwidth and thickness of the fiber bundle. The angle at which the fiber has an effect on the properties of the final product.
A high angle “hoop” will provide circumferential or “burst” strength, while lower angle patterns (polar or helical) will provide greater longitudinal tensile strength.
Products currently being produced using this technique range from pipes, golf clubs, Reverse Osmosis Membrane Housings, oars, bicycle forks, bicycle rims, power and transmission poles, pressure vessels to missile casings, aircraft fuselages and lamp posts and yacht masts.
Fiberglass hand lay-up operation.
A release agent, usually in either wax or liquid form, is applied to the chosen mold to allow the finished product to be cleanly removed from the mold.
Resin typically a 2-part thermoset polyester, vinyl, or epoxy is mixed with its hardener and applied to the surface. Sheets of fiberglass 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 be sure the resin saturates and fully wets all layers, and that any air pockets are removed.
The work must be done quickly before the resin starts to cure unless high-temperature resins are used which will not cure until the part is warmed in an oven.
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.
Fiberglass spray lay-up operation.
The fiberglass spray lay-up process is similar to the hand lay-up process but differs in the application of the fiber and resin 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.
Pultrusion is a manufacturing method used to make strong, lightweight composite materials. In pultrusion, material is pulled through forming machinery using either a hand-over-hand method or a continuous-roller method (as opposed to extrusion, where the material is pushed through dies).
In fiberglass pultrusion, 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. Fiberglass produced this way can be made in a variety of shapes and cross-sections, such as W or S cross-sections.
Different Types of Fiberglass.
Your choice of fiberglass isn’t limited to one or two types. There are many different kinds, so we’ve broken down the basics of 12 of them below to help you choose which will serve you best.
#1. E-Glass Fiber.
It’ll come as no surprise that E-glass or electrical glass, is superb for insulating electrical components. You’ll find it used in aerospace and industrial products because it’s lightweight and heat resistant.
The concoction you’ll need for this type of fiberglass includes silica, soda, potash, lime, boric oxide, magnesia, and alumina.
#2. D-Glass Fiber.
When you’re working with electrical appliances, optical cables, and cookware, you’ll want to rely on D-glass fiber. It can insulate these types of items because of its low dielectric constant. The star ingredient in this type of fiberglass is boron trioxide.
#3. R-Glass Fiber (Also Known As T-Glass or S-Glass Fiber).
Fiberglass already offers a pretty impressive resume of characteristics, but if you need something that performs even better, R-glass fiber is the one.
You also might find it by the T-glass or S-glass, and because of its acidic and tensile strengths, it’s usually found in products made for aerospace and defense industries.
#4. A-Glass Fiber.
This type of fiberglass is one you may come across in your everyday life. A-glass also goes by soda-lime glass or alkali glass, and it’s often turned into bottles, jars, and window panes.
It’s relatively cheap compared to other options, has chemical stability, and you can recycle it. In its mixture, you’ll find lime, alumina, dolomite, soda, silica, and sodium sulfate.
#5. Advantex Glass Fiber.
Advantex glass is trademarked, and it’s a version of the material you’d look to if you’re worried about corrosion caused by acids and temperature changes. That’s why it’s popular for manufacturers in the mining and oil industries.
It’s also found in places with the harshest and grimiest conditions, including power plants and sewage systems. You can expect to find a lot of calcium oxide in its makeup.
#6. ECR Glass Fiber.
If you’re after something similar to E-glass fiber but with extra heat and acid resistance, ECR glass fiber is the next step up.
It’s an environmentally friendly fiberglass that’s great if you’re looking to make durable panels that can handle water, heat, and impact without struggling.
#7. C-Glass Fiber.
C-glass also goes by chemical glass, and as you’d assume, it’s the perfect fiberglass if you need materials that are impact and chemical-resistant.
The calcium borosilicate in its makeup won’t let you down if you use it in environments (like pipes and tanks) that are exposed to water and chemicals.
#8. Z-Glass Fiber.
When you’re in need of a fiberglass that can provide heavy-duty reinforcements for concrete and other materials, you can look to Z-glass products like mesh. These have no problem handling acids, salt, wear and tear, and UV rays.
#9. S2 Glass Fiber.
This type of fiberglass is unique in that it can support you with reinforcing textiles. It’s a high-performing pick with unbeatable temperature resistance, compression, and impact resistance. You can even make aerospace cloth with it.
#10. AR-Glass Fiber.
You may also call AR glass alkali-resistant glass. It gets mixed in with concrete to prevent or at the very least slow down cracking.
This flexible fiberglass is strong and won’t falter if you need a material that won’t succumb to water or changes in the pH. To get it to this level, it has zirconia in its blend of ingredients.
#11. M-Glass Fiber.
Fiberglass may not sound like it could be truly that flexible, but M-glass fiber will happily prove you wrong.
It has plenty of elasticity and beryllium in its formulation, which means it’s a great option for making tableware, glassware, packaging, housing, and building materials.
#12. AE Glass Fiber.
Just when you thought there couldn’t be any more applications for fiberglass, the AE glass type arrives. It may sound niche, but it’s a popular material for monitoring and filtering air.
Its fibers cut down and trap unwanted particles without completely slowing down its flow rate. Whether you work in a lab or an environmental sector, you’ll probably be aware of this type.
Properties of Fiberglass.
- Mechanical strength: Fiberglass has a specific resistance greater than steel. So, it is used to make high-performance
- Electrical characteristics: Fiberglass is a good electrical insulator even at low thickness.
- Incombustibility: Since fiberglass is a mineral material, it is naturally incombustible. It does not propagate or support a flame. It does not emit smoke or toxic products when exposed to heat.
- Dimensional stability: Fiberglass is not sensitive to variations in temperature and hygrometry. It has a low coefficient of linear expansion.
- Compatibility with organic matrices: Fiberglass can have varying sizes and has the ability to combine with many synthetic resins and certain mineral matrices like cement.
- Non-rotting: Fiberglass does not rot and remains unaffected by the action of rodents and insects.
- Thermal conductivity: Fiberglass has low thermal conductivity making it highly useful in the building industry.
- Dielectric permeability: This property of fiberglass makes it suitable for electromagnetic windows.
Characteristics of Fiberglass.
Fiberglass has a variety of useful characteristics. For example, fiberglass composite materials like garolite G-10 FR-4, which is known for its fire retardancy. Here are some of the most common characteristics of fiberglass materials.
- Durable
- Stiff
- Lightweight
- Fire-resistant
- Excellent insulator
- Great chemical resistance
- Highly corrosion resistant
- Dimensionally stable
- Temperature and humidity-resistant
- Resistance to warping
- Moisture resistant
Applications for Fiberglass.
Materials with high-temperature insulation provide an effective thermal barrier for industrial gaskets.
Since fiberglass is durable, safe and offers high thermal insulation, fiberglass is one of the widely preferred materials in industrial gaskets.
They not only provide a better insulation but also help in protecting the machinery, conserving the energy and ensure the safety of the professional workforce.
This is the reason perhaps why fiberglass is widely used in industries given below:
- Beverage industry: Fiberglass grating is used in many areas like bottling lines and in brew houses.
- Car washes: Recently, fiberglass grating is greatly used for rust resistance and to give a contrast color to areas that previously looked forbidden. It brightens the inside of the carwash tunnel making the car look cleaner than it was.
- Chemical industry: In this industry, the fiberglass grating is used for anti-slip safety feature of the embedded grit surface and the chemically resistant feature of different resin compounds. The chemicals being used are matched with the resins.
- Cooling towers: Since cooling towers are always wet, they have to be protected from rust, corrosion, and other safety issues. Due to the excellent properties of fiberglass, it is used in these towers as screening to keep people and animals away from the danger zones.
- Docks and marinas: The docks get corroded, rusted and damaged by the salty sea water. So, fiberglass is used here for protection.
- Food processing: In the chicken and beef processing plants, fiberglass grating is used for slip resistance and for holding up to blood which is corrosive. Most of the areas of food processing also use fiberglass as other grating materials are not suitable.
- Fountains and aquariums: All sizes of fountains and aquariums use fiberglass to support rocks to help in circulation and filtering from under the rocks. In large public fountains, fiberglass grating is used to protect spray headers and lights from getting damaged. This also keeps people from drowning in the fountains.
- Manufacturing: The embedded grit surface of fiberglass grating ensures slip resistance in the areas that are wet or in places where hydraulic fluids or oils are present.
- Metals and mining: Fiberglass grating is used in electronic refining areas prone to chemical corrosion. Other grating materials cannot be used here.
- Power generation: Many areas of the power generation industry like tank farms, scrubbers, and others use fiberglass. The reason for this is the non-conductive property of fiberglass.
- Plating plants: This application uses fiberglass grating due to the anti-slip property of the surface.
- Pulp and paper industry: The property of fiberglass which makes it chemical corrosion resistant is useful in pulp and bleach mills. Recently, fiberglass is used in many areas due to its corrosion resistance and anti-slip properties.
- Automotive industry: Fiberglass is extensively used in automobile industry. Almost every car has fiberglass components and body kits.
- Aerospace & Defense: Fiberglass is used to manufacture parts for both military and civilian aerospace industry including test equipment, ducting, enclosures, and others.
Is Fiberglass Strong Enough?
When it comes to strength to weight ratio, fiberglass easily outperforms steel. Glass fiber provides the same strength as steel with greater flex, which means it’s more durable and impact resistant. It is also stronger than steel in the lengthwise direction with overall better dimensional stability.
The quantity, type, orientation, and location of the glass fibers within the composite determine the strength of a fiberglass profile.
The strength-to-weight ratio of Fiberglass Reinforced Plastic compared to metal or wood products can be up to 5 times bigger.
When it comes to reaching a buckling point, high tensile strength is essential. When used in harsh environments, fiberglass retains its integrity and is corrosion resistant.
According to market analysts, the amount of fiberglass produced in 2017 was worth nearly $14 billion.
They predict that by 2025, that figure will have risen to more than $21 billion, underscoring just how useful glass reinforcements are in consumer products.
Advantages and Disadvantages.
If you want to weigh up the advantages of fiberglass, first you’ll want to note that one of its main benefits is its strength. Actually, fiberglass has more tensile strength than steel, but it’s still lightweight.
It’s a great material if you need something that’s resistant to weather, water, and corrosive chemicals. It’s not conductive or magnetic, which earns it points when it comes to insulation and using it around other kinds of materials.
You’ll also find that fiberglass doesn’t rust, shrink, burn, or expand, making it durable and long-lasting.
Any material will have its limits though, including fiberglass. One of the disadvantages you may find with using it is that it’s expensive, especially when compared to non-composite materials.
Fiberglass is also hard to get rid of and doesn’t biodegrade, which isn’t ideal if you’re invested in sustainable practices.
If you have employees working with fiberglass, it can be hazardous to touch and breath in if the right safety equipment isn’t worn. With too much sunlight, you may also find that fiberglass fades.
Carbon Fiber and Glass-Reinforced Plastic vs. Fiberglass.
It should be noted that although it’s similar to both, fiberglass is not carbon fiber, nor is it glass-reinforced plastic. Carbon fiber is made of strands of carbon.
Though extremely strong and durable, carbon fiber cannot be extruded into strands as long as those of fiberglass because it breaks. This is one of several reasons that fiberglass, while it’s not as strong, is cheaper to manufacture than carbon fiber.
Glass-reinforced plastic is just what it sounds like: plastic with fiberglass embedded in it to increase strength. The similarities to fiberglass are apparent, but a defining characteristic of fiberglass is that the glass strands are the main component.
Glass-reinforced plastic is comprised mostly of plastic, so while it’s an improvement over plastic alone for strength and durability, it won’t hold up as well as fiberglass.
Recycling Fiberglass.
Although there hadn’t been much advancement in the recycling of fiberglass items once they’d already been produced, some new innovations in recycling technology and uses for recycled fiberglass products are starting to emerge.
One of the most promising is the recycling of outdated wind-turbine blades.
According to Amy Kover, a reporter for GE Reports, General Electric’s in-house news site, while replacing existing blades with more technically advanced ones can increase wind farm performance by as much as 25%, the process creates the inevitable waste.
“Crushing a blade yields about 15,000 pounds of fiberglass waste, and the process creates hazardous dust. Given their enormous length, sending them to a landfill whole is out of the question,” she noted.
In 2017, GE teamed up for a recycling initiative with a Seattle-area-based Global Fiberglass Solutions Incorporated (a company that’s been recycling fiberglass since 2008, and has patented a means to recycle old blades into products including manhole covers, building panels, and pallets).
In less than a year, GFSI recycled 564 blades for GE and estimated that in the coming years, GE would be able to re-manufacture or reuse up to 50 million pounds of fiberglass waste.
In addition, a great deal of fiberglass itself is currently manufactured from recycled glass.
According to the National Waste and Recycling Association’s newsletter “Waste360”, recyclers are turning broken glass into a viable resource known as cullet (glass that’s been crushed and cleaned), which in turn, is being sold to manufacturers of fiberglass insulation.
“Owens Corning uses more than one billion pounds of cullet every year for residential, commercial and industrial fiberglass applications,” they report.
Meanwhile, Owens Corning has stated that as much as 70% of their fiberglass insulation is now manufactured using recycled glass.