How to bond Carbon/Carbon Fiber (CRP)

CRP, also called CFRP, is a composite material with extremely high structural strength, making it popular for applications with high impact or high load. It is lightweight, and there is a strong need for adhesives to bond this material, as it cannot be welded, and mechanical fasteners not only increase the component's weight, but can also lead to loosening from vibrations and shocks, and can affect the material's structural integrity if drilling is required.

CRP, or carbon fiber reinforced polymer, is used for the construction of lightweight components and the manufacture of strong yet lightweight structures. CRP is also used to produce high-performance sports equipment, advanced medical prosthetics, and energy-efficient solutions. Its unique properties make it ideal for applications where the strength-to-weight ratio is crucial and where lightweight materials can improve performance and efficiency. It is used, for example, in wind turbines.

Surface tension can vary significantly depending on the composition of the specific CRP material. The estimate for the surface tension of carbon fiber reinforced polymer (CRP) typically ranges between 30 and 50 dyn/cm.

Torayca, HexTow, HexPly, SIGRAFIL, and SIGRAPREG are all well-known trade names for carbon fiber reinforced polymer.

Bonding

Clean and prepare surfaces thoroughly to remove dirt, grease, and impurities. Use a non-conditioning cleaning agent. Consider treating the surface with a primer or undergoing corona or plasma treatment before bonding, especially depending on the strength requirements of the bonded joint.

Choosing CRP adhesive:

• Cyanoacrylate adhesive cures very quickly upon contact with surfaces, reducing overall bonding time and enabling faster production processes. The resulting bond is strong and rigid, which is ideal for applications requiring high strength and stiffness. Cyanoacrylate adhesive also typically has good resistance to temperature variations and many chemicals, making it suitable for use in demanding environments. However, it is important to assess specific requirements for flexibility and shock absorption, as cyanoacrylate adhesive can be brittle and less flexible compared to other adhesive types like epoxy or polyurethane.
• Epoxy adhesive creates a strong and durable bond between carbon fiber and polymer composites, ideal for applications requiring high strength and reliability. It offers flexibility to adapt to different flexibility needs and resists chemicals, water, and temperature changes.
• Acrylic adhesive creates strong and durable bonds suitable for applications where reliable strength is critical. These adhesive types also offer flexibility, as they can be adjusted to achieve different degrees of flexibility, making them suitable for both structural and non-structural bonding. Acrylic adhesives are typically resistant to moisture and weather conditions, making them suitable for outdoor and environmentally exposed applications. Furthermore, many acrylic adhesive products are environmentally friendly with low VOC content or solvent-free, contributing to their environmental advantage.
• Polyurethane adhesive offers excellent flexibility and strength, making it ideal for applications requiring movement and shock absorption. It is resistant to moisture and weather, making it suitable for outdoor use. Additionally, it has good adhesion to various materials such as metal, plastic, and fiberglass and can cure quickly, streamlining the production process. Overall, these properties make polyurethane adhesive a reliable solution for bonding CRP in industries requiring durability and dependable strength.

Follow the manufacturer's instructions carefully regarding application and curing time.

After bonding, perform tests to ensure that the strength and durability of the adhesive joint meet the requirements of your specific application.

Manufacturers

Here are some trade names and manufacturers of carbon fiber reinforced polymer (CFRP):

Toray Industries is one of the world's largest carbon fiber manufacturers, known for its Torayca series, which includes a wide range of carbon fiber reinforced polymers (CFRP).

Hexcel Corporation also offers advanced composite materials, including their HexTow and HexPly series, well known in CFRP.

SGL Carbon, with their SIGRAFIL and SIGRAPREG products, is a key player in the market for carbon- and graphite-based materials.

Contact us

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