Modern mills are high-tech precision products

Material-dependent design

Tietjen mills are impact crushers. Each mill is adapted precisely to the material to be crushed or milled: capacity, humidity, intended granularity, starting sizes, material hardness, surface attributes – and the list goes on. This is why seven employees work on 3D design. All variants share a similar fundamental design: Arranged in segments, many hammers are attached to a rotor, which rotates in the chamber at over 3 000 rpm. The material, introduced from the top into the mill chamber, hits the hammers, which crush it as a result of the force of the high-speed impact. The company‘s core knowhow focuses on the arrangement of the hammers, and in particular the rotor design. „We use different steel grades for the hammers. Stainless steel is frequently used, as the materials are acidic or else relatively hard. It‘s crucial that the rotor is manufactured with great precision due to its rotational speed“, stated Peter Wagner, Tietjen‘s General Manager and Head of Production. The components were produced semi-automatically for many years. The continuous growth and the restricted space on the factory site made us think about purchasing a CNC machining center, which would allow us to produce more flexibly, faster and with a higher degree of precision. Another argument was the spare parts business. Tietjen is still producing replacement parts for mills that customers have had in operation since the beginning of the 1960s. These individual parts can be more efficiently produced with a higher repeat accuracy when using a CNC machine.

Offline programming with SinuTrain

This bold investment decision met with much praise internally. With the new machining center, key workflow steps which had previously been outsourced were re-integrated into the company, increasing our level of vertical integration. „This further improved our flexibility and supply capabilities. This gives us an important competitive edge in the project business, where milestones and completion dates are crucial,“ explained CEO Thomas Runde. The Sinumerik control system also played a part in this: Using SinuTrain, CNC programs are generated offline so that the machine can remain in productive operation for longer. „An extremely helpful option, which would not have been available with the original machine configuration. The Knuth machining center equipped with Sinumerik and SinuTrain, as well as the excellent collaboration between Knuth and Siemens, provide us with the best possible solution – packed with features and offering a high degree of flexibility.“

»The 3-axis machining center was not available with Sinumerik. But we made it possible for the customer...«