x
Send Your Inquiry Today
Quick Quote

Carbon Fiber Reinforced Plastic: Definition, Properties, Types, and Applications

Carbon fiber reinforced plastic (CFRP) is an advanced material known for its high strength and lightweight properties. It is increasingly used across various industries, from fishing rods to new energy vehicles. This article covers the definition, types, advantages, disadvantages, and applications of CFRP. Keep reading to learn more.

What Is Carbon Fiber Reinforced Plastic?

 

Carbon fiber reinforced plastic (CFRP) is a high-performance composite material made from carbon fibers and a polymer resin matrix. It is known for its excellent strength-to-weight ratio, stiffness, corrosion resistance, and low thermal expansion. Its applications span across various industries, from aerospace to civil engineering, maximizing its performance advantages.

What Is the Origin of Carbon Fiber Reinforced Plastic?

The origin of CFRP can be traced back to the development of carbon fibers themselves. The earliest known production of carbon fibers dates back to 1860 when Sir Joseph Wilson Swan created carbon fibers for early incandescent light bulbs. In the 1960s, the development of PAN-based carbon fibers and their combination with epoxy resins led to the creation of CFRP, a material with an exceptionally high strength-to-weight ratio and stiffness.

What Is Carbon Fiber Reinforced Plastic Made Of?

CFRP consists of two main components:

  1. Carbon Fibers: These provide the material with strength and stiffness. Carbon fibers are composed of carbon atoms arranged parallel to the fiber’s long axis, giving the fibers a high strength-to-volume ratio.
  2. Polymer Resin Matrix: This binds the carbon fibers together and transfers loads between them. The most commonly used resin is epoxy, though other thermoset or thermoplastic polymers like polyester, vinyl ester, or nylon can also be used. The choice of resin affects the final product’s properties, such as heat resistance, impact resistance, and flame retardancy.

How Is Carbon Fiber Reinforced Plastic Produced?

The production of CFRP involves various methods, each with its own advantages and applications. Here are some common manufacturing methods:

Wet Lay-Up

  • Process: Carbon fibers are laid onto a mold, wetted with resin, and then rolled or squeezed to remove excess resin. The layup can be left open or vacuum bagged, then cured at room temperature or under heat and pressure.
  • Advantages: Simple, versatile, low-cost, suitable for prototyping or small-scale production.
  • Disadvantages: Low efficiency for large-scale production, requires skilled labor.

Pultrusion

  • Process: Carbon fibers are pulled through a resin bath, then through a heated die to align the fibers axially and wet them with resin.
  • Advantages: Suitable for mass production of long, straight parts with high flexural strength.
  • Disadvantages: Limited to straight parts, low transverse strength.

Prepreg Lay-Up

  • Process: Prepregs are carbon fibers pre-impregnated with resin and partially cured to a tar-like consistency, then cured under heat and pressure.
  • Advantages: Produces strong, lightweight, stiff parts, ideal for flat parts or tubes.
  • Disadvantages: Poor drapeability over complex shapes, limiting the range of producible shapes.

Vacuum-Assisted Resin Transfer Molding (VARTM)

  • Process: Similar to lay-up, carbon fiber cloth layers are stacked in a mold with epoxy resin between them. The carbon fibers are vacuum-sealed in the mold, removing residual air and ensuring proper epoxy bonding.
  • Advantages: Produces consolidated laminates with minimal air voids.
  • Disadvantages: Higher cost due to additional materials and equipment.

Resin Transfer Molding (RTM)

  • Process: Dry fiber fabrics are placed between a male and female mold, which are then clamped together. Resin is injected under high pressure, transforming the soft fabrics into a hard composite within 30-60 minutes.
  • Advantages: Suitable for medium to small-sized products.
  • Disadvantages: Requires precise control of resin injection and pressure.

Autoclave Technique

  • Process: Prepreg layers are laid onto a forming mold, covered with a vacuum bag, and pressure is reduced before curing under heat and pressure in an autoclave.
  • Advantages: Suitable for producing high-quality, high-performance products.
  • Disadvantages: Long molding cycles, high cost.

Other Methods

  • Filament Winding: Resin-impregnated fibers are wound onto a mandrel and cured under heat.
  • Compression Molding: Uses molds to shape composite parts, cured under high pressure and temperature.
  • 3D Printing: Additive manufacturing techniques can also produce CFRP parts.

What Are the Properties of Carbon Fiber Reinforced Plastic?

CFRP exhibits a range of properties, including:

  1. Lightweight: CFRP has a density of 1.8 to 2.2, about 25% that of steel, making it significantly lighter.
  2. High Strength: PAN-based carbon fibers have an outstanding tensile strength, about 10 times that of steel.
  3. High Elastic Modulus: Pitch-based carbon fibers have an excellent elastic modulus, also about 10 times that of steel.
  4. Low Thermal Expansion: CFRP has a low coefficient of thermal expansion, meaning it does not expand or contract significantly with temperature changes.
  5. High Thermal Conductivity: While CFRP materials are highly conductive, they are also electrically conductive and require careful insulation during installation.
  6. Chemical Stability: CFRP resists corrosion and chemical degradation.
  7. Low Friction and Wear Resistance: Suitable for applications requiring high wear resistance.
  8. Damping Properties: CFRP effectively dampens vibrations, useful in noise reduction or vibration control applications.
  9. Corrosion Resistance: Ideal for environments where metals would degrade.
  10. High Fatigue Resistance: CFRP can withstand repeated stress cycles without significant degradation.
  11. Low Thermal Conductivity: While sometimes highly conductive, CFRP usually has low thermal conductivity, beneficial for insulation applications.
  12. Non-Magnetic: Crucial for applications sensitive to magnetic fields.

What Are Different Types of Carbon Fiber Reinforced Plastic?

Different types of CFRP are classified based on the raw materials and production processes used, resulting in various fiber specifications. The main types are:

  1. PAN-Based Carbon Fibers: Made from polyacrylonitrile (PAN) precursor, known for high tensile strength and high modulus, widely used in aerospace, industrial, and sports/recreational structural composites.
  2. Pitch-Based Carbon Fibers: Made from oil/coal pitch precursor, with a modulus ranging from low to ultra-high. Fibers with ultra-high modulus are used for high stiffness applications and can also be used for high thermal and/or electrical conductivity parts.

What Are the Limitations of Carbon Fiber Reinforced Plastic?

CFRP has several limitations, including:

  1. Brittleness and Susceptibility to Impact Damage: CFRP can fracture or shatter under compression, exceeding its strength capacity, or severe impact. It will crack if struck with a hammer, and machining or drilling can create weak spots.
  2. Poor Abrasion Resistance: CFRP is easily worn away by ordinary sandpaper, indicating poor abrasion resistance.
  3. High Cost: The production process of CFRP is complex and limited in yield, making it more expensive than other materials like steel or glass fiber. The cost of raw carbon fiber varies significantly, leading to a noticeably higher cost for CFRP materials.
  4. Electrical Conductivity: While highly conductive, this property can be a drawback in insulation-required applications. For example, products like ladders needing strict insulation might not be suitable for carbon fiber due to the risk of electrical shocks.
  5. Sensitivity to Notches and Holes: CFRP is sensitive to notches and holes, often weak in the thickness direction without fibers. Connection methods like bolting or clamping need careful consideration to avoid crushing.
  6. Complex Stress Analysis and Design: Due to its complex fiber structure, stress analysis and design of CFRP components can be challenging. Analysts and designers often require formal training in composite mechanics, finite element analysis, and related fields to ensure successful design and application.
  7. Environmental Sensitivity: CFRP composites may be sensitive to temperature and humidity, affecting their performance and durability.

What Are the Different Applications of Carbon Fiber Reinforced Plastic?

CFRP’s unique properties, including high strength-to-weight ratio, stiffness, and corrosion resistance, make it useful in various industries:

  1. Aerospace Industry: CFRP is used in constructing commercial aircraft, satellites, and other aerospace applications. It can be found in fuselages, tail fins, nose cones, rotor blades, airframes, wings, helicopter blades, rocket shells, and payload fairings, reducing aircraft weight by up to 20% and saving fuel costs.
  2. Sports Equipment: Carbon fiber is used in tennis rackets, skis, snowboards, bicycles, golf clubs, and other sports gear, enhancing speed and performance due to its lightweight nature.
  3. Medical Devices: CFRP is used in X-ray equipment and implants for its radiolucency and biocompatibility. It is also used in orthopedic implants, prosthetics, and MRI machines.
  4. Military: Initially used for naval vessel lighting, carbon fiber is now used in missiles, drones, helmets, and tent poles for its high strength and lightweight properties, facilitating transport and energy efficiency.
  5. Automotive: As costs decrease, carbon fiber is increasingly used in high-end vehicles and racing cars for body panels, hoods, roofs, spoilers, and structural components, improving fuel efficiency and handling.
  6. CivilEngineering: Carbon fiber reinforcements and cables can strengthen concrete, replacing traditional rebar. CFRP wraps and laminates reinforce structural components like columns and bridges.
  7. Consumer Electronics: Carbon fiber is used in high-end consumer electronics like laptops, phones, tablets, tripods, and headphones, making them lighter and more durable.
  8. Musical Instruments: Entire instruments like cellos, violas, violins, acoustic guitars, and ukuleles, as well as parts like piano strings and bagpipe chanters, are made from carbon fiber.
  9. Firearms: Carbon fiber is used to replace certain metal, wood, and fiberglass components in firearms, although many internal parts remain metal alloys.
  10. Miscellaneous: CFRP is used in high-performance drone bodies, lightweight rods (such as tripod legs, tent poles, fishing rods), dental applications (like carbon fiber posts for root canal-treated teeth), tramway bogies, laptop casings, and as filaments for 3D printing.

Is Carbon Fiber a Reinforced Plastic?

No, carbon fiber itself is not a reinforced plastic, but when embedded in a polymer matrix, the resulting composite material is called carbon fiber reinforced plastic (CFRP) or carbon fiber reinforced polymer. This composite combines the high strength and stiffness of carbon fibers with the versatility and molding capabilities of plastics, creating a lightweight, strong, and durable material. The polymer matrix, typically epoxy, polyester, vinyl ester, or nylon, bonds the carbon fibers together and helps distribute loads among the fibers.

Conclusion

We hope this guide has provided you with a comprehensive understanding of carbon fiber reinforced plastic. For more information about CFRP, feel free to contact us.

Looking Forward
Your Next Project!

Update cookies preferences
Scroll to Top