Adhesive bonding as a joining process for thermoplastic composite structures

Introduction
The application of thermoplastic technologies in aviation has increased in recent years for structural components. The requirements for the materials, manufacturing processes are increasing and in the scope of the European "Clean Sky" - (EU) project, new research fields have emerged. Next to the economic objectives, the ecological objectives have become increasingly important. In addition to the entire value chain, the recycling of components is also being considered. Thermoplastic technologies satisfy many requirements. For this reason, component manufacturing and structural assembly technologies are being investigated in different publicly funded research projects. Adhesive bonding technology offers great potential for structural assembly.

Adhesive Bonding
Currently, there is no non-destructive test method to prove the strength and durability of the adhesive bonding. This makes it difficult to make a quality statement about the adhesion. One way to implement structural bonding for the production of safety critical components in high volume production is to understand the bonding mechanism in the first step and to keep the parameters within defined parameter range in the second step. The achievement of the highest possible quality and reproducibility can be realized by a high degree of automation. In the achievement of the high degree of automation, the Thermoplastic Bonding research project encounters the LAILA project.

_{Figure 1 shows the part of the complete adhesive bonding process that is being considered in the Thermoplasic Bonding research project. The process steps that are to be monitored are also considered in the LAILA research project.}