The company was founded in 1947 by physicist Dr. Lehfeldt founded and offered only ultrasonic technologies for cleaning processes in medical technology. Meanwhile, KLN is a leading European manufacturer of machinery and components for welding plastic parts and specialized in industrial cleaning. The plastic welding machines from KLN offer solutions for practically all common plastic joining techniques. The focus is on ultrasonic, vibration, heating element, infrared and spin welding. Added to this are laser welding and thermal processes such as hot air and hot riveting.

The spectrum of industrial cleaning technology ranges from special ultrasonic flow systems and spray systems to solvent systems and modular systems. It includes ultrasonic oscillating tanks as well as components such as dryer systems, generators and ultrasonic transducer plates.

The use of modern production equipment and methods through its own laser cutting and painting plant, through its own toolmaking promotes flexibility and at the same time reduces manufacturing costs. The company is at home in many industries such as in plastics technology, automotive, mechanical and plant engineering, medical and packaging technology, tools, energy and solar technology, electroplating and the electronics industry.