Adhesives for Composite Materials

Master Bond produces a variety of high performance adhesives for the assembly of composite products. Cutting-edge adhesive formulations are available for bonding fiber composites to themselves and numerous different substrates. These versatile adhesives are available as liquids, pastes and also as films to meet the modern day demand for composite bonding. They are designed to provide the highest mechanical strength and peerless performance even upon exposure to extreme conditions.

Performance Properties

The unique nature of the composites has made them extremely popular for high tech applications requiring lighter weight and higher strength. Bonded interfaces exhibit outstanding impact/fracture toughness, tensile, compressive, creep, stress fracture and shear capabilities. Other advantageous properties include resistance to thermal cycling, cryogenic shock resistance, low shrinkage, electrical insulation, resistance to chemicals, mechanical shock resistance and serviceability in extreme temperatures, to name a few.

Surface Preparation for Composites

Some of the most commonly used composites include carbon fiber, glass fiber, kevlar and graphite reinforced composites. Most often, these substrates are easily bondable. However, it is important to carry out the necessary surface preparation in order to ensure good bonding. Many times, composites are coated with a mold-release agent or a gel coat, which inhibits its ability to be bonded well to other substrates. Hence, thorough degreasing needs to be carried out to provide a surface free of any contaminants. Frequently, mechanical abrasion of the composites is also carried out to further improve its bond strength. However, caution must be exercised to make sure that the reinforcing fibers are not exposed or damaged while abrading. A combination of both techniques can also be carried out for optimum results.

Composites Bonding Best Practices

After preparing the surfaces, a uniform layer of the adhesive should be applied and the parts placed together. It is important to fixture the parts while the adhesive sets up to ensure good contact between the adhesive and the substrates. However, care should be taken to not apply excess pressure, to limit adhesive squeeze out from between the substrates. Film adhesives are ready to use and require no mixing. They provide a uniform bond line thickness and offer minimum flow while curing.

Typical Applications for Composite Adhesives

Master Bond custom formulates products with specific performance properties designed for unique applications where composite materials are used. Some examples of such applications include:

• Liquid shim epoxies for composites
• Adhesives for bonding of honeycomb sandwich panels
• Aircraft interior cabin
• Wind turbine blades
• Sports equipment
• Carbon fiber sports cars
• Medical prosthetics
• Tanks

These compounds have been successfully employed in aerospace, medical, optical, electrical, electronic and other manufacturing industries.