4.2f - Composites

What is a composite?

• A mixture of two or more materials

• One material acts as the matrix (the glue)

• The other material acts as reinforcement (fibres, sheets, or particles)

What are the components that can make up the matrix and reinforcement in composites?

• Matrix: Thermoplastics, thermosetting plastics, ceramics (e.g., concrete), metals

• Reinforcement: Textiles, glass, plastics, wood, carbon

What does the process of moulding involve, and where is it used?

• Moulding is a process where material is shaped into a specific form by pouring or pressing it into a mold.

• The material can then harden in the desired shape.

• Example: Used in creating complex shapes such as car body panels in fibreglass or plastic

What is pultrusion, and where is it used?

• Pultrusion is a continuous process used to produce long, straight composite materials.

• It involves pulling reinforcing fibres through a resin bath and then curing them in a heated die.

• Example: Used for producing fibreglass rods, structural beams, and boat masts.

What does lamination mean in the context of composites?

• Lamination refers to bonding multiple layers of material together with adhesive to form a strong, uniform structure.

• Layers can consist of wood, textiles, or plastics.

• Example: Laminated Veneer Lumber (LVL) uses laminated thin layers of wood for structural applications in buildings.

What are the components of concrete?

Concrete is a composite made up of:

• Water

• Portland cement

• Aggregates

  • (e.g., gravel)

What is Engineered Wood, and what are some examples?

• Engineered wood (also known as composite wood or manufactured board) is made by gluing sheets, particles, or strands of wood together.

• Examples include:

  • Plywood: Sheets of veneer glued together

  • Particleboard: Chips of wood glued together

What are some common applications for Plywood?

• Construction: Flooring, roofing, and wall paneling

• Furniture: Bookshelves, desks, cabinets

• Exterior Uses: Marine ply for boats

What is Fibreglass, and what are its applications?

• Fibreglass is made from strands of glass, formed into a mat, then covered in resin (polymer/thermoset plastic).

• Applications:

  • Boats

  • Pools

  • Bathtubs

  • Vehicle bodies

What is Kevlar®, and what are its uses?

• Kevlar® is a para-aramid synthetic fiber covered in resin.

• Applications:

  • Armour

  • High-performance sports equipment (canoes, kayaks)

  • Ropes, tyres, sails

What is Carbon-reinforced plastic and where is it used?

• Carbon-reinforced plastic is made by bonding carbon fibres in a mat, then covering with resin.

• Uses:

  • Car racing

  • Sports equipment (golf clubs, tennis rackets)

  • Aviation (e.g., Boeing Dreamliner)

What is Laminated Veneer Lumber (LVL), and where is it used?

• LVL is made from thin layers of wood glued together.

• Applications:

  • Structural uses in buildings (e.g., beams, lintels)

What are the advantages of using composite materials?

• Composites can be designed with specific properties tailored for applications.

• Lightweight, strong, durable, and customizable.

• Improved performance compared to traditional materials

What are the disadvantages of composite materials?

• High cost compared to traditional materials.

• Production processes can be complex and require skilled labor.

• Not always environmentally friendly (depending on the materials used).