Every time the eccentric press strikes the red-hot iron with its piston, the forge hall vibrates. Men grab the forged parts with long iron tongs and pile them into large metal baskets. Even though the bluish display of an industrial PC shimmers just a few meters away, there is always something archaic about this process. Krenhof primarily sees itself as a supplier of raw parts for drop forgings, but in exceptional cases it also takes on machining tasks. The company's products include fittings for formwork technology and the chain industry, as well as gear wheels, shafts, flanges, connecting rods and similar items for the automotive industry. The company also produces a range of different forged parts for mechanical engineering, railroads and agricultural machinery.

Shocks, vibration and 1200 °C heat

In order to manufacture the aforementioned products and semi-finished products, the metal parts must first be cut to size and then heated to temperatures of between 950 and 1200 °C. The hot metal part is then formed between two die halves. Using high pressure generated by the piston of an eccentric press, the hot metal part is formed between two die halves. The workpieces are then treated with heat to relieve stresses within the parts that could potentially deform them.

Industrial PCs record and process machine and operating data as well as personnel times in an industrial forge.

© Noax

As considerable rationalization potential can also be exploited in such processes, seamless data acquisition in production is essential. At Krenhof, this task is performed by robust industrial PCs from Noax. Before these IPCs were implemented, information on production output was recorded on paper forms: Employees had to stop what they were doing and write down the data by hand. At the end of the shift, employees took these forms to the typing pool, where the information was manually typed into an office PC. This procedure not only cost time - errors also crept in time and again.

As industrial PCs can be used to collect more accurate and, above all, more meaningful information, the management staff at Krenhof decided to record the operating and machine data as well as staff times automatically. Economical production is shown, among other things, by a certain output per hour, as the CEO of the public limited company explains: "These are concrete key figures. Without them, we don't know whether we are covering our costs or not. We developed an initial action plan to record all production times and quantities. The aim was to achieve completely transparent production."

In 2011, Krenhof introduced the industrial PCs from Noax and installed the MES software from Proxia on them. "The high performance of the overall system, the robust, completely closed industrial PC with touchscreen, the modular, stable software solution with its intuitive user interface and the modern look and feel of the software all spoke in favor of this combination."

Robustness is a must

In addition to the easy handling of the PDA terminals, robustness is essential for use in a metal processing company. Forges are virtually the prototype of a harsh production environment. Due to the stresses and strains in production, conventional PCs cannot be used: Soot, graphite dust, metal splinters, water vapor and vibrations would bring an ordinary computer to a standstill within a few hours.

For Krenhof, the completely enclosed design of the IPCs in accordance with protection class IP65 is particularly important, as the forge uses a graphite-water suspension to lubricate the parts during the production process. The extremely conductive graphite dust escapes into the air and settles on all surfaces, including the computer hardware. However, due to the completely waterproof and dustproof design, neither the graphite dust nor other contaminants penetrate the interior of the industrial PCs.

40 % less set-up time

Once the first industrial PCs had been implemented, those responsible took the next step in the optimization process, as the Management Board reports: "The introduction of mandatory reporting really got the whole continuous improvement process (CIP) rolling. We also use the industrial computers for this purpose. As soon as an interruption in production exceeds a defined limit value, every employee must use the comment field in the PDA software to state the reasons for the delay."

The employee enters the current operating data into the Noax terminal on the column on the right. The touchscreen also responds to operation with gloves.

© Noax

The threshold for mandatory reporting is 80 minutes for product changes and 15 minutes for tool changes alone. "From this point onwards," continues the CEO, "our set-up times suddenly fell by 40%!" Company management and shift supervisors can now see both the quantitative main and secondary times as well as the qualitative reasons for machine downtimes.

The data transparency also has consequences for the management staff, as the CEO explains: "The introduction of the industrial PCs and the MES system was the birth of communication between employees and the management levels: Employees let us know immediately when problems arise. We are then called upon to eliminate these problems as part of a CIP workflow. This two-way communication allows us to meet each other on an equal footing in a spirit of trust. This has greatly improved employee motivation and acceptance of the system."

In addition, the recorded key figures help to make economically sensible decisions: The responsible employees in the company management immediately recognize from the evaluations by the MES whether it is better, for example, to purchase a new machine or hire more staff. Due to the consistently positive experience, the company management is planning to use the Noax IPCs and the MES from Proxia outside of production as well.

Author: Michael Naumann is a freelance trade journalist from Munich.