FRP Composite Material And Its Applications | Science & Technology for UPSC CSE PDF Download

Fibre-Reinforced Plastic (FRP) - An Introduction

• Fibre-Reinforced Plastic (FRP), also known as a fibre-reinforced polymer, is a composite material that consists of a polymer matrix reinforced with fibres. This combination of materials results in a strong and lightweight material with excellent mechanical properties, making it a popular alternative to traditional materials like steel, wood, aluminium, and concrete.

History and Early Development

• The concept of FRP dates back to the early 20th century when the first fibre-reinforced plastic, Bakelite, was developed.
• Bakelite was one of the earliest thermosetting plastics, and it laid the foundation for the development of modern FRP composites.

Materials Used as Fibre in FRP Composites

• Glass: Fibreglass is one of the most commonly used fibres in FRP composites due to its high strength and relatively low cost.
• Carbon: Carbon fibres offer exceptional strength and stiffness, making them suitable for applications that require high performance.
• Basalt: Basalt fibres are derived from natural volcanic rock and possess good mechanical properties.
• Aramid: Aramid fibres, such as Kevlar, are known for their high strength-to-weight ratio and are often used in aerospace and military applications.
• Other Fibres: In some cases, fibres like paper, wood, or asbestos are also used for specific applications.

Materials Used as Polymers in FRP Composites

• Epoxy: Epoxy resins are widely used as the polymer matrix due to their excellent mechanical properties, adhesion, and chemical resistance.
• Vinylester: Vinylester resins offer good resistance to corrosion and are commonly used in applications where the composite material will be exposed to harsh environments.
• Polyester: Polyester resins are cost-effective and find use in various applications, from marine structures to automotive parts.
• Phenol Formaldehyde: Phenol formaldehyde resins are used in certain specialized applications due to their exceptional heat and chemical resistance.

Manufacturing Processes for FRP Composite Materials

• Pultrusion is used to create FRP composites with regular and uniform shapes like bars, beams, and rods.
• In this process, fibres are pulled through a heated steel die, saturated with resin, and then drawn through the die to mold them into the required shape.

Filament Winding

• Filament winding is primarily employed to produce parts for tanks and pipes.
• Long fibres that have been wet with resin are twisted around a mold to create the desired shape.

Hand Lamination

• Hand lamination is a cost-effective method to manufacture complex forms like the hull of a boat or an airplane's fuselage.
• Fibres are arranged in a fabric over a mold and then wet with resin.

Vacuum Infusion

• Vacuum infusion is used to create FRP components that are incredibly light and have excellent mechanical properties.
• FRP components with resin and fibres are placed within vacuum bags to increase resin penetration into the fibre cloth.

Advantages of FRP Composites

• High Strength-to-Weight Ratio: FRP composites offer exceptional strength while being lightweight, making them ideal for various applications.
• Corrosion Resistance: FRP materials are highly resistant to corrosion, making them suitable for use in harsh environments.
• Design Flexibility: The manufacturing processes allow for complex shapes and designs to be achieved easily.
• Electrical and Thermal Insulation: FRP composites are excellent electrical insulators and have good thermal properties.
• Long Service Life: FRP structures often have a longer service life compared to traditional materials due to their inherent durability.

Properties of FRP Composites

• Strength Dominated by Fibre Component: In FRP composites, the fibre component primarily contributes to the material's strength. The matrix's role is to encase and distribute forces among the fibres.
• Superior Strength-to-Weight Ratio: The glass fibre, commonly in the form of woven cloth or fibre mats, exhibits greater strength than steel concerning its weight.
• Lightweight: FRP composites are exceptionally light, making them ideal for weight-sensitive applications.
• High Tensile Capacity: These composites demonstrate strong tensile strength, enabling them to withstand pulling forces without breaking.
• Corrosion and Water Resistance: FRP composites possess inherent resistance to corrosion and water, making them suitable for use in harsh environments.
• Electrical Conductivity Resistance: The non-conductive nature of FRP composites ensures they do not conduct electricity, making them suitable for certain electrical applications.
• Chemical Compound Resistance: FRP composites exhibit resistance to various chemicals, enhancing their applicability in chemical and corrosive environments.
• UV Stability: These composites can endure exposure to ultraviolet (UV) radiation without significant degradation, making them suitable for outdoor applications.

Applications of FRP in Aviation and Automobile Industry

• Aerospace Industry: FRP composites find extensive use in the aviation sector due to their exceptional strength-to-weight ratio. They are employed in aircraft components, such as wings, fuselage sections, and tail structures, reducing overall weight and improving fuel efficiency.
• Automobile Industry: In the automotive sector, FRP composites are utilized for their lightweight properties, which contribute to increased fuel efficiency and reduced emissions. They are employed in body panels, bumpers, and interior components.
• Weight Savings: FRP composites offer significant weight savings, making them desirable for both aviation and automotive industries, where reducing weight is crucial for improved performance.
• Precision Engineering: The inherent strength and stiffness of FRP composites allow for precise engineering, enabling the creation of intricate and complex designs.
• Finite Tolerances: FRP composites can be manufactured with tight tolerances, ensuring consistency in production and enhancing overall quality.
• Simplified Part Design: With the versatility of FRP composites, complex assemblies can often be simplified into single molded parts, reducing assembly time and costs.
• Cost-Effectiveness: Manufacturing molded polymer artifacts using FRP composites is generally cheaper, faster, and easier than casting aluminum or steel artifacts, while still maintaining comparable or even better tolerances and material strengths.