Maximum performance, minimum wear

In the production of PET bottles using the stretch blow molding process, one machine produces up to 90,000 bottles per hour. The most important components that make this top technical performance possible come from Switzerland. More precisely, from Wetzikon, where Eugen Seitz AG has been manufacturing high-performance valves since 1958.

#Ematal anodising #Mechanical engineering 

Ansprechperson Beitrag

Rubbi Rothenfluh

Sales Manager Industry


“Our valves are complex systems where the interaction of seal, surface and lubrication (“tribosystem”) determines the service life of the valves,” explains Dr. Pasieka, expert in sealing technology and tribology at Seitz. For the target market of PET bottle production, Ematal has proven to be the ideal surface. In combination with the initial lubrication, friction between the aluminum components and the seals is minimized. It is important that the lubricant adheres well to the Ematal coating and is not worn away, thus ensuring constant sliding behavior.

In the Seitz test laboratory, the “tribosystems” of newly developed valves are tested with up to 60 million switching cycles at a frequency of 2.5 Hz. Over a period of 14 months, corresponding valves are switched 150 times a minute with additional pressurization. The massive stress can only be withstood by perfection in design and manufacturing, as well as by a suitable choice of materials and seals. “The fact that we can use Ematal both as a resistant functional layer and as a distinctive design element is a great advantage for us,” explains Dr. Pasieka.

Over the past 10 years, therefore, more than 1.5 million valve components have been ematalized by BWB-Betschart AG in Schlieren. All valves manufactured from this material were tested on a specially developed test rig before leaving the Eugen Seitz AG factory. The Ematal coating withstood both internal testing and customer exposure. “We are not aware of any surface defects that have led to customer complaints,” notes Mr. Girelli, COO of Seitz, with satisfaction.

Do you also have a special requirement for the surface of your aluminum components? We will be happy to assist you in defining the appropriate coating.

More references

Discover more articles and references about our current projects and services.