Adaptive laser transmission welding based on inline optical tomography

The laser transmission welding is an established single-stage plastic joining process, which enables hermetically sealed joints under the workpiece surface. This process requires a joining partner with transmissive and a partner with a high degree of absorption to the processing wavelength. In order to reach a stable process a control unit is required. Current monitoring systems have a limited usage, as no quantitative information of the real weld seam is obtained (e.g. narrowing or interruption). In medical and pharmaceutical applications a weld seam with leakage is e.g. unacceptable. The main project objective is therefore the implementation of a laser transmission welding controlled by inline optical tomography. This approach enables the acquisition of quantitative information of the weld forming process as detection of weld geometry, pores and leakage as well as partner gap. This information will be processed and feedback to a control unit, which will adapt in real-time process parameters based on a special developed process and control model with simulative support