Composite materials are everywhere, even if we don’t always notice them. From the cars we drive to the sports gear we use, composites play a big role in creating strong, durable, and lightweight products. But what exactly are composite materials? Understanding them can help us appreciate the technology that goes into making some of our everyday items.

In this guide, we’ll explore what composite materials are, the types we commonly use, how they are made, and the benefits they bring to various industries.

What Are Composite Materials?

Composite materials are special because they combine two or more different substances to create a new material with unique properties. Each substance in a composite gives its best qualities to the final product. For example, when carbon fibers and epoxy resin are combined, they form a strong and lightweight material that is much tougher than either substance alone.

Composites are used in many everyday items. They make our cars lighter and stronger, help airplanes fly more efficiently, and even protect athletes with tough yet flexible gear. The magic lies in how these materials are put together, making them more versatile and reliable than traditional materials like metal or wood.

Types of Composite Materials

Carbon Fiber Composites

Carbon fiber composites are made from tiny fibers of carbon that are incredibly strong and stiff. These fibers are woven together and mixed with a resin to create a super-strong material. Carbon fiber composites are often used in high-performance products like sports cars, bicycles, and aircraft. They are prized for being both strong and lightweight, making them perfect for places where performance and weight matter most.

Fiberglass Composites

Fiberglass composites are made from fine fibers of glass. These fibers are woven into a fabric, which is then combined with a resin. The result is a material that is strong, light, and durable. Fiberglass is commonly used in things like boat hulls, car bodies, and even some types of sporting equipment. It is less expensive than carbon fiber but still offers great strength and versatility.

Kevlar Composites

Kevlar is another type of fiber that is incredibly strong and heat-resistant. It is best known for its use in bulletproof vests, but Kevlar composites are used in many other applications too. When combined with a resin, Kevlar fibers create a material that is lightweight, strong, and resistant to high temperatures. This makes Kevlar composites ideal for protective gear, military applications, and even high-performance tires.

How Are Composite Materials Made?

Layering Process

Making composite materials starts with a layering process. Thin layers of fibers, like carbon fiber or fiberglass, are laid out in a mold. Each layer is carefully positioned to ensure the fibers are aligned in the right direction. This alignment is crucial because it determines the strength and other properties of the final product. Multiple layers are stacked to achieve the desired thickness and strength. The more layers, the stronger the composite material will be.

Curing and Hardening

Once the layers are in place, the next step is curing and hardening. This involves adding a resin, which binds the fibers together. The layered material is then heated to cure the resin. During this curing process, the resin changes from a liquid to a solid, locking the fibers in place and giving the composite its strength. At Finishline, we use advanced ovens and autoclaves to ensure the materials cure evenly and meet high-quality standards. After curing, the composite material is removed from the mold and trimmed to its final shape.

Benefits and Uses of Composite Materials

Strength and Durability

Composite materials are known for their incredible strength and durability. Unlike metal, they do not rust or corrode. This makes them ideal for use in harsh environments, where materials like steel might fail. For instance, carbon fiber composites are used in aerospace and automotive industries because they can withstand high stress without breaking. This strength means products made from composites last longer and require less maintenance.

Lightweight Applications

Another key benefit of composite materials is their lightweight nature. Despite being strong, they are much lighter than traditional materials like metal and wood. This makes them perfect for applications where weight is critical. For example, aircraft and racing cars use composites to reduce weight and improve performance. Athletes also benefit from lightweight composite equipment, which can enhance their performance and reduce fatigue.

Common Industries and Products

Composite materials are used in a wide range of industries and products. In the aerospace industry, composites are used to make aircraft components that need to be strong but lightweight. In the automotive industry, they are used in everything from body panels to performance parts. Athletes rely on composite materials for gear like tennis rackets, bicycles, and helmets. Even wind turbine blades are made from composites because they need to be strong, light, and durable to function effectively.

Conclusion

Composite materials have revolutionized many industries with their unique properties. Understanding these materials helps us appreciate the technology and craftsmanship that go into creating high-performance products. Whether it’s the strength and durability of carbon fiber or the lightweight benefits of fiberglass, composites offer solutions that traditional materials simply can’t match.

At Finishline, we specialize in the manufacturing and repair of composite materials. Our state of the art equipment and expertise ensure that every project meets the highest standards of quality. If you’re looking to learn more or to start a project using composite materials, reach out to us. Get the best quality and composite consulting service with Finishline. Give us a call today!

Advantages of Composites
Light Weight – Composites are light in weight, compared to most woods and metals. Their lightness is important in automobiles and aircraft, for example, where less weight means better fuel efficiency (more miles to the gallon). People who design airplanes are greatly concerned with weight, since reducing a craft’s weight reduces the amount of fuel it needs and increases the speeds it can reach. Some modern airplanes are built with more composites than metal including the new Boeing 787, Dreamliner.                                 

High Strength – Composites can be designed to be far stronger than aluminum or steel. Metals are equally strong in all directions. But composites can be engineered and designed to be strong in a specific direction.

Strength Related to Weight – Strength-to-weight ratio is a material’s strength in relation to how much it weighs. Some materials are very strong and heavy, such as steel. Other materials can be strong and light, such as bamboo poles. Composite materials can be designed to be both strong and light. This property is why composites are used to build airplanes—which need a very high strength material at the lowest possible weight. A composite can be made to resist bending in one direction, for example. When something is built with metal, and greater strength is needed in one direction, the material usually must be made thicker, which adds weight. Composites can be strong without being heavy. Composites have the highest strength-to-weight ratios in structures today.

Corrosion Resistance – Composites resist damage from the weather and from harsh chemicals that can eat away at other materials. Composites are good choices where chemicals are handled or stored. Outdoors, they stand up to severe weather and wide changes in temperature.

High-Impact Strength – Composites can be made to absorb impacts—the sudden force of a bullet, for instance, or the blast from an explosion. Because of this property, composites are used in bulletproof vests and panels, and to shield airplanes, buildings, and military vehicles from explosions.

Design Flexibility – Composites can be molded into complicated shapes more easily than most other materials. This gives designers the freedom to create almost any shape or form. Most recreational boats today, for example, are built from fiberglass composites because these materials can easily be molded into complex shapes, which improve boat design while lowering costs. The surface of composites can also be molded to mimic any surface finish or texture, from smooth to pebbly.

Part Consolidation – A single piece made of composite materials can replace an entire assembly of metal parts. Reducing the number of parts in a machine or a structure saves time and cuts down on the maintenance needed over the life of the item.

Dimensional Stability – Composites retain their shape and size when they are hot or cool, wet or dry. Wood, on the other hand, swells and shrinks as the humidity changes. Composites can be a better choice in situations demanding tight fits that do not vary. They are used in aircraft wings, for example, so that the wing shape and size do not change as the plane gains or loses altitude.

Nonconductive – Composites are nonconductive, meaning they do not conduct electricity. This property makes them suitable for such items as electrical utility poles and the circuit boards in electronics. If electrical conductivity is needed, it is possible to make some composites conductive.

Nonmagnetic – Composites contain no metals; therefore, they are not magnetic. They can be used around sensitive electronic equipment. The lack of magnetic interference allows large magnets used in MRI (magnetic resonance imaging) equipment to perform better. Composites are used in both the equipment housing and table. In addition, the construction of the room uses composites rebar to reinforced the concrete walls and floors in the hospital.

Radar Transparent – Radar signals pass right through composites, a property that makes composites ideal materials for use anywhere radar equipment is operating, whether on the ground or in the air. Composites play a key role in stealth aircraft, such as the U.S. Air Force’s B-2 stealth bomber, which is nearly invisible to radar.

Low Thermal Conductivity – Composites are good insulators—they do not easily conduct heat or cold. They are used in buildings for doors, panels, and windows where extra protection is needed from severe weather.

Durable – Structures made of composites have a long life and need little maintenance. We do not know how long composites last, because we have not come to the end of the life of many original composites. Many composites have been in service for half a century.