Non-contact laser welding

In the felds of plastics cutting, welding and perforating, laser technology is an established and recognised practice and very much needed in such industries as automotive. Thanks to the latest laser technology, new fields of application in material processing keep opening up to bring high quality welding.

Jenoptik’s Lasers & Material Processing division recently demonstrated its competence in plastics processing via its non-contact laser welding with the Jenoptik-Votan W. The product meets the growing demand for vehicle interior equipment to meet standards for safety, to enable automotive manufacturers to overcome one new challenge after the other. The Jenoptik model of laser machine for plastics welding has broadened the field of application of transmission welding, Jenoptik has developed a welding process involving a laser line that can be switched on and off in sections. This novel process has successfully been applied in the industry several times already.

The non-contact joining method without any mechanical and thermal influence is not the only essential benefit of this new technology. It also results in high productivity and comparatively low operating costs. This innovative method is applied in the transmission welding of large plastic components, e.g. welding of chute channels in instrument panels, welding of interior/exterior trim parts or heat exchangers in dishwashers.

Multiple diode laser line for quality

Innovative Jenoptik diode lasers with a width of 10 millimeters (mm) and an optical laser power of up to 100 watts per submount for the standard wavelengths of 808, 940 and 980 nanometers are used for the newly developed laser welding technique. The diode laser line that can be switched on and off in sections, comprises eight diode laser submounts in a compact housing and generates a line of about 100 mm in overall length. Each submount can be switched on and off individually based on the contour to be welded and thus produce nearly any welding geometry.

By combining several diode laser lines in one overall line, the so-called diode nest, various component sizes can be welded in a highly productive way during one and the same passage – up to an area of maximally 1,500 mm x 600 mm. “Because almost every line width is possible, we are able to flexibly meet our customer’s requirements with our laser welding machine JENOPTIK-VOTAN W”, says Andreas Buechel, product manager at the Lasers & Material Processing division for the laser welding of plastics.

Inside the laser welding machine, the diode nest moves along a linear axis, across the components to be joined, and firmly welds them to each other without leaving any marks (sinks) on the top surface or causing any thermal distortion – at welding speeds of up to 100 mm/s. In order to ensure a constant weld quality, the entire welding process is made subject to online process control for quality assurance. When directly comparing this to alternative joining technologies, the strengths (pulling forces) of the welded joint in the boundary area and of the cover are 25 percent higher on average.

With its Lasers & Material Processing division, Jenoptik is one of the leading providers of laser technology and provides products and solutions along the entire value-added chain of laser material processing – from components up to complete laser systems. In the Lasers business unit, the company has specialised in high-quality semiconductor lasers, reliable diode lasers as modules or systems as well as innovative solid-state lasers such as disk and fiber lasers. This product portfolio makes Jenoptik the ideal partner for the entire pulse width range, from cw to fs. In the field of high-power diode lasers, the company is acknowledged as a worldwide quality leader. In the Laser Processing Systems business unit, Jenoptik develops and manufactures laser machines which are integrated into its customers’ production lines as a part of their process optimization and automation. It serves companies engaged in the processing of plastics, metals and glass in connection with the processing of thin films. Jenoptik laser systems ensure processing at maximum efficiency, precision and safety. In addition, customers can try out various laser sources and machines at the Application Centres thus finding the optimal solution for their application. The product portfolio is rounded off with energy-efficient and environmentally friendly exhaust cleaning systems for residue-free removal of pollutants during laser processing and other industrial processes.