Bühler Group is launching the Nutrex 7 Series, its next generation of extrusion systems.

Building on 40 years of extrusion manufacturing for cereals, snacks, pet food, meat alternatives, food ingredients and more, one central element remained unchanged: the twin-screw extrusion technology that has been serving in hundreds of machines around the world for decades.

“We focused on a holistic approach based on four main categories: hygienic design, process stability, integrated intelligence and service excellence, all with the aim of increasing overall equipment efficiency (OEE) for our customers,” says Stefanie Hardtmann, product manager, value nutrition at Bühler.

With the Nutrex 7 Series, Bühler aims to the diverse requirements of various applications using a modular concept. Since extrusion technology is used to manufacture a range of products across different industries, the system must be designed for different process requirements. What all applications have in common is that the systems must be operated safely. In the food industry and pet food sector, high hygiene requirements and maximum uptime in 24/7 operation, as well as high performance ranges, are the priority.

“Here, we drew on four decades of experience based on hundreds of installed systems around the world,” says David Meile, project manager, R&D, at Bühler. “A decisive factor was viewing the extrusion system as a whole in the context of the food processing chain.”

Nutrex 7 Series is designed for short and efficient cleaning processes. “Externally, we focused on a slimmer design for the extruder,” Meile says. “The elevated base frame creates more ground clearance, and the hydraulic box has been integrated from the base frame to the side of the extruder. This allows direct access with cleaning equipment, simplifying cleaning and shortening cleaning time.”

This hygiene concept is complemented by new cleaning solutions such as the patented Cleaning Lance, which enables effective internal cleaning and improves safety for operating personnel. The system is made of stainless steel and designed for wet cleaning from both the outside and the inside. The concept is supported by new automation and digital service solutions. Options such as Critical Control Point (CCP) Monitoring and the OEE app help continuously monitor processes, document deviations traceably and support targeted corrective measures. This can reduce the effort required for audits and validation. In addition, together with RedLog, Bühler offers the Extrusion Kill-Step Validation Service, which provides customers with a robust basis for evaluating extrusion as a critical process step.

Another central component is integrated intelligence. The fully revised control system is the flagship of Bühler’s automation strategy, which aims to standardize all machine and plant control systems on a single platform by 2030. 

“An extruder is not simply a machine, but an integrated process step in the food industry,” says Adrian Staerkle, team manager, R&D automation software at Bühler. “Our new visualization concept does justice to this complexity and maps the various processes – such as preconditioning, weighing, extruding and cutting – schematically across various levels. In addition, the control system is completely browser-based, meaning the processes can be monitored and controlled from anywhere.” 

With these new features, operators can detect any messages and alarms more quickly and reduce downtime. The system is complemented by new control hardware with a stainless-steel, 24-inch screen, designed for expandability and incorporating the latest components.

The new StepFlow function now gives customers the option of leaving the ideal settings for start-up and shutdown directly to the machine, based on Bühler’s expertise gathered over decades in hundreds of systems. 

Bühler’s partnerships with its customers enabled the team to develop Nutrex 7 Series with producers from various areas such as pet food, extruded flours and cereals, and to test them in industrial operation. One of the first test customers for Nutrex 7 Series is Kärntner Mühle in Austria. Decades ago, the company expanded its portfolio and added the production of specialty mixes for the baking industry to its traditional flour production. 

“As the first customer of Nutrex 7 Series, we were closely involved in the development process,” says Martin Kropfitsch, owner and managing director of Kärntner Mühle. “The collaboration with Bühler was partnership-based and practical. We were particularly impressed by the simple integration into our existing line and the significantly simplified handling. The intuitive control system makes day-to-day operation noticeably easier.”

Additional Nutrex 7 Series units are in operation at test customer sites. The system is available for order and delivery immediately.