Composites today are used in innumerable applications because of their lightweight feature. Growing demand for efficient technical systems requires lightweight components that have become an integral part of product development. Thus, composites have revolutionised the manufacturing industry by offering materials of unparalleled strength, flexibility, and durability. Composite parts have become a significant part of diverse industries, from defence and construction to automotive and sporting goods. This material is preferred over traditional metals because of its lightweight properties and ability to withstand harsh weather conditions without affecting its performance.
Composite material is a material made from two or more distinct components. These components are combined to create a composite material having a better set of properties than the individual component alone. The common composite material constituents a reinforcing material like glass or carbon mixed in a matrix material like resin or plastic. The matrix material binds the fibers together and evenly distributes the applied force for overall durability. This further results in creating a composite material that is durable, stronger, lighter, and resistant to environmental factors like chemicals, heat, and wear and tear.
Some commonly used composite materials include:
Carbon Fiber Reinforced Polymer (CFRP) – Used majorly in automotive, aerospace, and sports goods industries, this composite material is known for its durability and high strength-to-weight ratio.
Glass Fiber Reinforced Polymer (GFRP) – This composite material is preferred in construction and marine applications because of its affordable price, durable quality, and corrosion resistance.
Kevlar – It is a high-strength composite material that is light in weight and resistant to heat. This material is widely used in protective clothing and equipment like body armour and helmets.
There are several manufacturing processes for fabricating composite parts. The selection of a manufacturing process for making composite parts generally depends on the composite material, and the end-use or application. Some of the commonly used composite part manufacturing processes include:
Hand Lay-Up – This is one of the simplest and highly traditional methods employed in the manufacturing of composite parts. In this process, reinforcing fibers like glass or carbon are manually placed into a mould, and then resin is applied. The resin used in this process is cured either at room temperature or under heat and pressure to harden it. The hand lay-up process is preferred for manufacturing large, low-volume parts like wind turbine blades or boat hulls.
Filament Winding – To cater to the requirement of manufacturing cylindrical composite parts like tanks, pipes, and pressure vessels, the filament winding manufacturing process is used. In this, continuous fiber strands are wrapped in a precise manner around a rotating mandrel and are later impregnated with resin. The mandrel is removed after the curing process which leaves a highly strong and lightweight composite material.
Resin Transfer Molding – It is a highly automated process in which dry fibers are placed into a closed mould and then resin is injected under pressure. The fibers are impregnated by the resin and later on, the part is cured in the mould. This manufacturing process produces high-quality composite parts having excellent surface finishes. This manufacturing process is employed to manufacture composite parts that are used in aerospace and automotive industries where precision and consistency are crucial.
Autoclave Molding – This manufacturing process is adopted to produce high-performance composite parts that are usually required in the aerospace industry. Under this manufacturing process, resin-impregnated fiber layers are laid into a mould that is vacuum-bagged and placed in an autoclave. The composite part is then subjected to high heat and pressure to compact the material and to ensure uniform curing. This manufacturing process produces composite parts that have excellent durability and strength.
Pultrusion – Long and straight composite parts like beams, rods, and channels are usually made through the pultrusion manufacturing process. This manufacturing process involves pulling fibers first through a resin bath and then through a heated die to give shapes and cures the material. It is preferred to manufacture composite parts that are used in infrastructure, construction, and energy applications.
Some of the prominent benefits of composite materials include:
Lightweight – Composite materials are lightweight compared to other metals like steel and aluminium. Thus, composite material is preferred in industries like automotive and aerospace where light weight leads to better fuel efficiency.
High Strength and Durability – The exceptional strength of the composite materials along with their ability to withstand harsh environmental conditions make them ideal to be used across marine, oil and gas, and industrial sectors, where materials are required to endure challenging conditions.
Design Flexibility – Composite materials provide manufacturers with great flexibility to create parts with complex shapes, sizes, and geometries that are hard to achieve using conventional methods. This feature makes composite materials valuable for aerospace and architecture industries that require parts with intricate and customized designs.
With the ongoing research and development in this sector, the future of composite parts manufacturing looks promising. The industry is looking for ways to optimize the production process and enhance cost-efficiency, and sustainability of composite materials. With the industry adopting advanced technologies like automation, robotics, and 3D printing, the manufacturing processes will be further streamlined leading to reduced costs. The composite materials parts usage is likely to expand further in new industries. With the demand for lightweight and durable materials growing, composite parts will play a key role in shaping the manufacturing industry across the globe.
In the field of material science, advanced composites have emerged as high-potential materials that stand out as transformative forces. Made from two or more constituent materials having different physical or chemical properties, the composite material has characteristics different from the individual components. Due to new and unique mechanical and physical properties, advanced composite materials are replacing conventional materials in diverse fields of applications like automotive, aeronautical, aerospace, and biomedical.
Advanced composites comprising of a matrix like a polymer, metal, or ceramic are reinforced with fibers like carbon, glass, or aramid and have revolutionized industries ranging from aerospace and automotive to sports equipment and renewable energy. The crux of advanced composites lies in their ability to blend the best properties of their constituents. For instance, carbon fiber-reinforced polymers (CFRP) offer a remarkable blend of high strength-to-weight ratio, stiffness, and corrosion resistance. This makes them ideal for applications where weight reduction is crucial without compromising structural integrity.
Advanced composites, also known as polymer composites, are created by merging a reinforcement material such as fiberglass, carbon fiber, or aramid fiber with a resin, which is essentially a type of polymer. This combination harnesses the strength of the fiber and the distinctive advantages of the polymer, such as fire resistance or chemical resistance. The manufacturing of polymer composites offers numerous methods, tailored to the desired properties, shape, and volume of the application. The manufacturing process of advanced composites is intricate and demands precision. The most common methods include:
Lay-Up Process – This involves manually placing layers of composite fibers in a mold, followed by pouring thermoset resin over the fiber layer. Pressure is applied using a hand roller to compact the fiber layer and impregnate it with thermoset resin. It’s a labour-intensive process but allows for high customization and is widely used in producing large structures like boat hulls and wind turbine blades. This method is widely used in the marine industry because of its low cost and simplicity.
Filament Winding – Filament winding is a technique mainly used to produce hollow, circular, or prismatic components like pipes and tanks. This process involves winding continuous fiber tows onto a rotating mandrel with a specialized winding machine. Filament-wound parts are widely used in the aerospace, energy, and consumer product industries. In this process, fibers are wound around a rotating mandrel in specific patterns and then impregnated with resin. This technique is excellent for creating high-strength cylindrical structures like pipes and pressure vessels.
Pultrusion – It is an automated manufacturing process in which continuous lengths of fibers are pulled through a resin bath and then through a heated die to form a constant cross-section profile. In this process reinforced fibers, pigments, and liquid pultrusion resins are pulled through a heated die, converting into composite materials. It’s highly efficient for producing uniform, high-strength composite materials like beams and rods.
Resin Transfer Molding (RTM) – In this process, fibers are cut into desired sizes and then placed in the lower half of a mold. The fiber is compacted until the desired thickness is achieved and then enclosed with a rigid upper mold. The resin is injected into the mold with injection pressure, filling the voids and creating a solid composite structure. RTM offers high dimensional accuracy and surface finish, making it suitable for complex shapes. This process is used to manufacture composite parts that have high mechanical properties and excellent surface quality.
Recent advancements in composite manufacturing have focused on improving efficiency, reducing costs, and enhancing material properties. Some notable innovations include:
Automated Fiber Placement (AFP) and Automated Tape Laying (ATL) – These technologies automate the placement of composite fibers, significantly increasing production speed and accuracy while reducing labor costs.
Additive Manufacturing (3D Printing) – The integration of additive manufacturing with composite materials is opening new possibilities. By printing with composite filaments or using continuous fiber reinforcement, complex and lightweight structures can be produced with minimal waste and lead time.
Nanotechnology – Incorporating nanomaterials like carbon nanotubes and graphene into composites can enhance their mechanical, thermal, and electrical properties. These nanoscale reinforcements can improve the performance of composites in applications ranging from electronics to aerospace.
Sustainable Composites – With growing environmental concerns, there is a push towards developing eco-friendly composites. This includes using bio-based resins and natural fibers and creating recycling processes for composite materials to reduce waste.
Advanced composites manufacturing is at the forefront of material innovation, driving progress across multiple industries. As technology continues to evolve, the development of more efficient, cost-effective, and sustainable manufacturing processes will further expand the applications of advanced composites. This ongoing revolution in materials science promises to deliver unprecedented performance and efficiency, shaping the future of engineering and design.
