World market leader in heavy lifting bridge systems replaces all welding robots

The Stertil Group with its head office in the Frisian town of Kootstertille develops and builds dock levellers under the Stertil Dock Products name and lifting bridge systems under the Stertil Koni brand. The products are sold worldwide through eight sales offices plus their own production facilities in the USA and China as well as a dealer network.

Limited efficiency during welding production

When the current CEO took over the man¬agement of Stertil around 14 years ago, the company was writing red figures. “It was time to develop a clear strategy. On the basis of thorough market research and a business analysis, we set up a new organization and put together a new management team. One of the first weak points we encountered in produc¬tion was the limited efficiency in (welding) production. The components for the dock levellers and lifting bridge systems are built in a multitude of types and sizes, in which a separate tacking and welding fixture was used for each type and dimension. The existing robots always had to wait until the fixture had been changed and the workpiece had been tacked. As a result, these robots were forced to stand idle for a long time. Efficiency had to be increased considerably,” Ulbe Bijlsma explains.

To a modular structure

One of the initiatives was the implementa¬tion of a modular product design for the dock levellers. Then, on the basis of this, an optimal method of production was examined. “We had developed an automatically adjustable fixture, in which we could quickly switch between the different models. By having the tacking process run parallel with the welding robot, the robot additionally was not forced to wait for the tacking, therefore it was possible to double the duty cycle. With this, we said farewell to the old method of working”, Jan Bosch explains.

Improved cycle

“We have considerably improved the entire cycle of tacking, welding and cleaning by means of the modularisation of the product design, automation effort, offline programming and modern welding fixtures. Since we have performed these improvements both with the production of the dock levellers as well as the lifting bridge systems, both departments are no longer strictly separated, but instead employees work on components for both product groups. Furthermore, the first welding robot installation of Valk Welding has already been taken into operation in our USA branch. The programs, which were created and used in the Netherlands, can be applied one-to-one, without any corrections due to the calibration of the systems” Jan Bosch explains.

Improve output further

“The replacement of the first welding robot was a nerve-racking event; both the new method as well as the new technology first had to prove itself. However, everyone quickly saw the benefits, as a result of which the new method and the new welding robots were rapidly accepted. In the meanwhile, we have become a key account at Valk Welding. We are happy to benefit from their knowledge and points for improvement are quickly implemented and we are able to continuously raise the bar. In this manner, Valk Welding helps us in improving the output further,” Ulbe Bijlsma states. www.stertil.com