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It’s all upwards from here – Sulzer’s individual pump solutions in the oil and gas, energy and water treatment sectors can reach several thousand meters of head.

From left to right: Kim Strasser; Voislav Bozic; Robin Rettberg
From left to right: Kim Strasser, CAM programmer; Voislav Bozic, machine operator; Robin Rettberg, manufacturing technology engineer

Founded in 1834 in Winterthur, Switzerland, the company has been developing pumps for industrial applications since 1860. Sulzer also concentrates on the manufacture of complex rotating components as well as on separation, mixing and application technologies. With 180 production and service locations worldwide and 16,500 employees, the company works closely with its customers and takes innovative approaches to manufacturing, as demonstrated by the acquisition of a LASERTEC 65 3D hybrid (NEW: DED hybrid) from DMG MORI. Sulzer has been setting new standards in the manufacture of impellers using laser metal deposition since 2018.

Blade wheels are among the most heavily stressed components in pumps designed by Sulzer. Particulates in the liquids and acids can cause enormous wear. Nevertheless, the components are designed for a service life of 20 years. “The systems work much longer, however,” explains Robin Rettberg, who is responsible for manufacturing technologies at Sulzer. “If an impeller like this has to be replaced, our customers need a spare part quickly.” As these are mostly custom-made products, the company is unable to simply rely on its stocks.

Conventional process – 25 weeks lead-time

The ability to add material and mill workpieces alternately means that impellers can be manufactured with channels that run up to 360 degrees around the wheel.

The challenge with impellers lies in their complex geometry. The conventional manufacturing process includes the design and production of a mold, casting of the raw part and then final machining of the impeller, but it is not possible to reach all areas of the raw part using traditional methods. “The impellers have channels that sometimes run up to 360 degrees around the wheel,” says Robin Rettberg. The complex process could take a total of at least 25 weeks.

New way of process optimization and increased efficiency through hybrid manufacturing

When additive manufacturing had developed into a serious production alternative, Sulzer began to look at the different processes. While the first powder bed solutions involved difficulties in post-processing and were limited to layers to build up material, in 2018 DMG MORI come up with a solution in the form of a hybrid complete machining concept on a LASERTEC 65 DED hybrid. Based on a 5-axis machining center, the LASERTEC 65 DED hybrid combines additive manufacturing using a powder nozzle with sophisticated and highly precise milling to within microns in one clamping. “This allows us to alternately build almost any geometry in 5 axes and to finish mill important component areas before they are no longer accessible,” says Robin Rettberg, describing the process. “This includes areas that were previously unable to be machined in the casting.” Improved surfaces allow Sulzer to achieve higher efficiency. There is also a further advantage over the earlier powder bed solutions: “Component diameter is not restricted by a build chamber of limited size.” The LASERTEC 65 DED hybrid offers travels of 735 × 650 × 560 mm.

SIEMENS NX – hybrid CAD / CAM for product development, design and manufacture

Sulzer uses SIEMENS NX for CAD and CAM programming. Even at this early stage, there is a need for new ways of thinking about additive manufacturing to achieve optimal results.

Robin Rettberg was quickly confronted with a typical challenge of additive manufacturing after introducing the new process: “New ways of thinking are necessary as early as the design stage to ensure the potential of hybrid manufacturing can be fully exploited.” Sulzer therefore uses SIEMENS NX for CAD and CAM programming. The software has been developed in cooperation with design engineers from DMG MORI and SIEMENS and is the most powerful solution in the area of powder nozzle technology from programming to production.

Advanced additive process – one week lead-time

The original manufacturing process for complex impellers took as long as 25 weeks due to the production of the casting mold. Additive manufacturing on the LASERTEC 65 DED hybrid reduces this to less than a week.

Manufacturing impellers continues to be a complicated process. The design and programming alone take up approximately half a week. Ultimately, the new hybrid process is many times faster. “We are able to reduce the entire lead-time from 25 weeks down to less than one,” Robin Rettberg is pleased at the milestone. The fast material build rate of the LASERTEC 65 DED hybrid also contributes to this. Depending on the material, it is 1 kg per hour.

Now that Robin Rettberg and his team have established a reliable process for manufacturing impellers on the LASERTEC 65 DED hybrid, Sulzer is sure that this is a pioneering solution. “We would like to continue to increase capacity in this area as the technology allows us to react even more flexibly to customer requirements.”

Should our current machine no longer be able to meet demand, we have already had a look at the LASERTEC 125 DED hybrid from DMG MORI. It offers the same technology and hardware with which we are already very familiar and well trained. Due to its size, it also opens up the option of processing components up to ø 1,250 mm and 745 mm in the Z-axis, and up to a max. weight of 2,000 kg.



  • Specializes in pumps, agitators, mixers, separators and application technology for all kinds of fluids
  • 16,500 employees worldwide
  • 180 production and service locations
  • Sales of 3.7 billion CHF

Sulzer Management Ltd.
Neuwiesenstrasse 15
8401 Winterthur, Switzerland

Contact us for all issues related to the DMG MORI technical press.