Composite materials are combinations of two or more materials designed to improve physical and mechanical properties. Their history dates back to 1500 BC, when the Egyptians began using mud and straw to build sturdy houses.
In recent years, composites have undoubtedly come a long way. With the advent of resins in the 1900s, technology has advanced further, leading to the widespread use of composites in industrial and recreational applications. Fiber-reinforced polymers (FRP), produced using the pultrusion process, have proven to be a popular choice, and they are now used in various applications, from fence posts to F1 racing components.
Common Pultruded Fibers
The four primary fibers used in fiber-reinforced polymers are glass fiber (GFRP), carbon fiber (CFRP), aramid fiber (AFRP), and basalt fiber (BFRP). Each has its unique features and applications.
Aramid Fiber
Aramid fiber is an organic polymer produced by spinning solid fibers from a liquid chemical mixture.
Advantages: Good tensile strength and modulus. Aramid is lightweight and has excellent heat resistance. It offers superior bulletproof and impact resistance.
Disadvantages: High production costs limit its use to specific applications.
Glass Fiber
Glass fiber is the most popular polymer reinforcement material due to its price and performance.
Advantages: Fiberglass's tensile strength is twice that of aluminum and lighter. It is also corrosion-resistant and highly resistant to chemical attack.
Disadvantages: Lower strength compared to carbon fiber.
Applications: The use of GFRP is expanding to include mining rock bolts, piers, and grapevine support rods. Over the past 30 years, civil engineers have extensively used GFRP rebar for concrete reinforcement in areas prone to corrosion.
Cost: A cost-effective option with excellent versatility.
Carbon Fiber
Carbon fiber is primarily made from an organic polymer bonded together by carbon atoms. CFRP is replacing aluminum in the aerospace industry. It is lightweight, reducing fuel consumption.
Advantages: Excellent strength-to-weight ratio. Low thermal expansion. It is highly resistant to chemical corrosion and does not rust.
Disadvantages: High cost is the biggest obstacle.
Applications: Aircraft components, racing car parts, tennis rackets, and bicycle frames—all benefiting from their light weight, strength, and high performance.
Cost: Higher overall cost.
Basalt Fiber
Basalt fiber uses basalt rock and is processed similarly to glass fiber.
Advantages: Good chemical resistance.
Applications: Basalt rebar for concrete reinforcement.
Cost: More expensive than glass fiber.
As we continue to develop new technologies and improve existing ones, composites play an increasingly important role in providing better performance solutions and extending service life to enhance durability.
