Induction welding is highly suited to joining thermoplastic composite materials. The thermoplastic polymer in the matrix can be melted by the addition of heat, and with the application of pressure and after sufficient time, a weld is made. Welding avoids some of the problems associated with adhesive bonding of composites; a difficulty with thermoplastics.
In the past, induction welding has been carried out using a metal susceptor in the form of a braid or mesh at the weld interface. Although very effective, this can result in difficulties with NDT or create problems with lightning strike in aircraft. Also, the retention of a metal implant may affect the welded component’s mechanical properties. The challenge is to create a weld that uses the carbon fibres of the composite as the susceptor, which can be done but introduces further difficulties of thermal management to prevent overheating of the parts being welded. The target is a process that does not rely on a metallic susceptor but is quick and easy to carry out.
Being very geometry dependent, much of the innovation required is specific to a component such as a stiffener to skin on an aircraft.
TWI has considerable experience in both the practical application and also the modelling of the induction welding process. We have been satisfying clients' needs by providing solutions to composites welding for over twenty years. Our advantage comes from our depth in materials technology in polymers, composites, surface preparation, welding processes and modelling.
The benefits of a successful project are typically a successful process that enables a new material to be used in an application, or in the reduction of cost or energy required to carry out the welding process.
TWI has over 25 years of successful induction welding projects, including several patent applications.
For more information, please contact us.