Composites
What are Fiber Reinforced Composites
Carbon fibers were first used in the 1860s as filaments for light bulbs. As the light bulb evolved, so did the filament and about 100 years later, the first high performance carbon fibers were developed. However, it was not until the 1970s though that reliable carbon fibers were produced industrially. At that time there was extensive research being carried out in the field on carbon fiber reinforced (CFR) composites. Since the 1970s there has been massive development in the sector of carbon fiber use in almost all sectors of the economy. The weight-strength ratio has been widely perfected and the knowledge of the handling process and production of high performance and high-quality carbon fibers has grown.
Glass fiber production was possible from an early age on. The ancient Egyptians and Greeks knew how to melt glass a long time ago. At that time, the fibers were produced with low quality and were not really used as material reinforcement. It was not until the 1930s that the process was developed to produce continuous fibers in order to use them as glass fiber reinforced (GFR) composites. Since glass fibers were introduced into commercial use, they have found their way into a lot of different sectors of the economy. Glass fibers are often used for insulation of buildings or cables but can also be used in structural components.
Glass fibers can be found in products from pole vault poles to honeycomb composite structures in aircrafts. There really is no limit to the possibility of its application because there is such a wide variety of manufacturing methods.
Generally speaking, fiber reinforced composite is a combination of fibers and a resin matrix material. Depending on the application different raw material types can be used such as dry laminate, prepreg or fiber tailored materials. At Swiss Fibertec, we use high-quality prepreg material supplied by certified manufacturers for the autoclave production process. Prepreg is an abbreviation for pre-impregnated fabrics. This means that the fibers are impregnated with the resin matrix prior to part manufacturing by the supplier of the raw material. The prepreg material is impregnated in a controlled environment in order to guarantee an even distribution of the resin matrix in material.
Benefits of fiber reinforced composites vs. metal
1. High Strength-to-Weight Ratio: Carbon fiber composites are incredibly strong in comparison to their weight. They are stronger than steel and are much lighter, achieving an excellent strength to weight ratio. At the same weight, carbon fiber composite can achieve a tensile strength and stiffness increase by a factor of 5 in comparison to steel, meaning that as a rule of thumb 1kg of CFC can replace 5kg of steel. This property makes them ideal for applications where weight reduction is critical, such as aerospace, automotive, and sporting goods.
2. Stiffness: Carbon fiber composites have a low modulus of elasticity, meaning they are very stiff. This stiffness makes them suitable for applications where rigidity and stability are essential, such as in the construction of aircraft wings and structures, highly stressed automotive components and sporting equipment.
3. Corrosion Resistance: Carbon fiber does not corrode or rust, unlike metals such as steel. This makes carbon fiber composites particularly valuable in harsh environments, such as marine or chemical processing applications.
4. Fatigue Resistance: Carbon fiber composites can withstand repeated stress and loading cycles without experiencing fatigue failure, making them suitable for components subjected to dynamic loads, such as in the aerospace and automotive industries.
5. Design Flexibility: Carbon fiber composites can be tailored to have specific mechanical properties by adjusting the fiber orientation and resin composition. This flexibility allows engineers to design components with precise strength and stiffness characteristics for their intended applications.
6. Aesthetics: Carbon fiber composites are often chosen for their sleek and modern appearance. They are used in consumer products like high-end bicycles, luxury car parts, and consumer electronics for their aesthetic appearance.
7. High-Temperature Resistance: Carbon fiber composites can withstand high temperatures, making them suitable for use in components exposed to extreme heat, such as in aerospace and industrial applications.
8. Low Thermal Expansion: Carbon fiber composites have a low coefficient of thermal expansion, meaning they do not expand or contract significantly with temperature changes. This property is valuable in applications where dimensional stability is critical.
9. Vibration Damping: Carbon fiber composites can absorb and dampen vibrations, making them useful in applications where vibration control is important, such as in sporting goods and industrial machinery.
Prepreg & ITS BENEFITS
Pre impregnated fabric materials are manufactured in controlled environments in order to guarantee an even distribution of the resin matrix on the raw fibers. The fabric can be acquired in different orientational styles, meaning that the fibers are woven with the help of different techniques. Through this, a wide range of different material properties can be used for specific purposes. Most commonly plain weave material is used.
1. Precise Resin Control: Prepreg technology allows for precise control over the resin content and distribution, ensuring consistent and predictable mechanical properties in the final composite.
2. Storage Stability: Prepreg materials can be stored for extended periods without curing, making them convenient for manufacturers and reducing waste.
3. Reduced Labor: Compared to wet layup processes where resin is applied manually, prepreg materials can reduce labor requirements and potential errors in resin distribution.
4. Improved Quality: The controlled manufacturing environment of prepreg production minimizes the risk of voids, resin-rich areas, and other defects in the final composite.
5. Customizable: Engineers can customize prepreg materials by selecting the type of reinforcing fibers, resin system, and fiber orientation to meet specific performance requirements.
Part Manufacturing Process
In the production of fiber-reinforced composites, tools are produced in advance of the part manufacturing process, which are then used to produce the final component. This means that a negative mold of the part is created before the final part is produced. Depending on the size of the part, Swiss Fibertec either uses direct tools or creates a carbon negative tool from a positive tool. This allows the exact control of the thermal expansion of the material.
Swiss Fibertec was the first company in Switzerland to apply casted shapes or tools in order to produce the tools for the final composite parts for clients. This allows Swiss Fibertec to produce large scale parts for a wide range of client appliances.
Each composite part, undergoes a curing cycle in an autoclave. During this process, the autoclave is pressurized and heated, so the resin matrix can harden and the material becomes geometrically rigid.
After the curing cycle, the part is demolded from the mold and further processed to ensure that the dimensions match the final technical specifications. Here, grinding, cutting, polishing, drilling and various different attachments are combined into a final product.
• Aerospace: Carbon fiber composites are widely used in aircraft components like wings, fuselages, primary and secondary structure, engines and interior structures to reduce weight and enhance fuel efficiency.
• Automotive: High-performance vehicles often incorporate carbon fiber composites in components like body panels, chassis, and interior trimed to reduce weight and improve performance and aesthetics.
• Sporting Goods: Carbon fiber composites are used in the production of lightweight and high-strength sporting equipment, including bicycles, tennis rackets, golf clubs, and hockey sticks.
• Marine: Boat hulls and components can benefit from carbon and glass composites’ corrosion resistance and high strength-to-weight ratio.
• Industrial Equipment: Carbon fiber composites are used in various industrial applications, such as robotic arms, pressure vessels, and other components requiring high strength and durability.
• Consumer Electronics: Carbon fiber composites are sometimes used in premium consumer electronics and gadgets for their lightweight and fashionable appearance.