Corrosion protection for weld-free vibration screening machine

A newly developed vibrating screening machine without weld seams places high demands on corrosion protection. This is because the coating system must be extremely resistant, which is ensured by a special zinc melting technology.

Haver & Boecker Niagara, supplier of processing technology, and the Zinq Group from Gelsenkirchen, Germany, have developed a new design for vibrating screening machines together with other partners. The redesigned Niagara T-Class screening machine is the first of its kind to completely dispense with weld seams and combines a hybrid design with a high-performance MicroZinq surface finish. This combination not only increases the machine's fatigue strength and cost-effectiveness, but also ensures sustainable use of resources.

Marcus Lindenlauf, Business Development at Zinq Technologie GmbH, the Zinq Group's innovation hub, emphasizes: "This project is a prime example of how interdisciplinary collaboration can produce innovative results." Vibratory screening machines such as the T-Class series from Haver & Boecker are crucial for the efficient processing of bulk materials. The screen box is constantly excited with four times the acceleration due to gravity, resulting in up to one million load changes per day. Welded seams in particular pose a risk to fatigue strength in such high-load areas.

Together in an interdisciplinary team consisting of experts from Zinq Technologie as the Zinq Group's think tank, Haver & Boecker Niagara, AML Bulk Technology and with the help of the latest findings from research work at technical universities, a new type of hybrid design without weld seams was developed. Instead of welded seams, only riveted and bolted connections are used to increase the fatigue strength of the machine.

However, this change placed new demands on corrosion protection: the coating system had to be extremely resistant, provide an optimum basis for hybrid connections and at the same time be economical and sustainable. Painted components were out of the question due to the thickness of the coating and the possibility of subsidence. The solution was found in MicroZinq, a surface based on an innovative zinc melting technology that is optimally tailored to these new requirements.

MicroZinq offers an extremely resistant, uniform surface that is ideal for screw and hybrid connections. The technology saves up to 80 % zinc - without compromising on corrosion protection. Thanks to the strong bond between MicroZinq and the base material, there is no need for time-consuming finishing work, which significantly optimizes production processes. "The decision to use MicroZinq as a sustainable corrosion protection solution has once again shown that technological excellence and resource conservation can go hand in hand," says Marcus Lindenlauf.

"The teams from Zinq Technologie, Haver & Boecker and other partners worked together intensively and trustingly for several years to technically implement the unique combination of a weld-free design and a resource-efficient MicroZinq surface. We wanted to be able to galvanize the surface without any time-consuming finishing," recalls Klaus Fennenkötter, Head of Design and Production at Haver & Boecker Niagara. "And when we finally had all the parts of our revised 'construction kit' on site, the design engineers at Haver & Boecker quickly became fitters and assembled the first micro-galvanized prototype of the new T-Class themselves."

The first Niagara T-Class with MicroZinq corrosion protection was successfully put into operation at the end of 2022. Since then, nine machines have proven their worth worldwide - from gravel to limestone plants. And the collaboration continues: with the partnership concept based on Zinq 360, uncoated components from various upstream suppliers are specially assembled for Haver & Boecker at Zinq and galvanized just in time, which once again significantly optimizes the processes in final assembly. (OM-3/25)