Safely extrusion of food
New grade of steel for twin-screw extruders

Tailored specifically to the requirements of the food and animal feed industry our partner Extruder Experts has developed a specialized steel grade distinguished by its excellent resistance to abrasion, corrosion, and wear.

Wear and corrosion: an ongoing struggle
This primarily concerns screw elements for co-rotating twin screw extruders, which vary depending on their precise function as conveying, kneading, and mixing components, and come into direct contact with the food mass. This exposure ultimately leads to wear, posing certain risks.

Firstly, friction-induced wear is notable. Since extruder elements rotate at tremendous speeds – up to 1,200 revolutions per minute are possible – and ideally operate continuously, wear presents a significant challenge. Secondly, aggressors such as acids or heat can lead to corrosion. The third factor is unique to the food industry: since water is often used abundantly, cavitation can occur. Cavitation involves the formation of gas bubbles in the liquid, which eventually implode, resulting in small, intense shockwaves that damage the screw elements.

Risks to health and reputation
Due to the stress on the wearing parts, contaminants such as chromium or nickel can enter the food, and in the worst case, even metal splinters. The potential consequences for health and reputation are evident. Discolorations such as streaks caused by rust particles are also unfavorable for the product’s reputation and the manufacturer. Furthermore, old and burnt product residues adhering to the extruder parts and re-entering the current mass can diminish the eating experience. In the extreme, this can lead to production downtime, recalls, financial losses, and loss of trust for the manufacturer.

Innovative solutions
To reliably prevent all this while also meeting increasingly stringent EU standards for food production (1935/2004/EC), creativity and innovation are required. Our partner, Extruder Experts, based in Monschau and serving international clients, is committed to taking this path. This approach materializes in the form of a specially developed metallurgy, specifically tailored to the requirements of the food and animal feed industry. This specially developed steel grade has not been previously used for this purpose and is approved in accordance with Regulation 1935/2004/EC. Among other features, the material stands out for its high resistance to wear, corrosion, and abrasion, as well as exceptional ductility. This property prevents splintering of metal parts. Furthermore, the steel’s characteristics ensure that product mass does not adhere.

More information
Curious about what the new twin screw extruders can mean for your specific production process? Please contact us.