Atlas Copco compressors supply printing shop with air for a variety of requirements

The precisely cut packages coming out of the folding machine in the production hall of the Bähren printing shop are smaller than a business card. It is hard to imagine that these "outserts" were once thin sheets of paper half a square meter in size. These are one of the bestsellers at the Mönchengladbach-based printing shop, which specializes in package inserts and adhesive labels for the pharmaceuticals industry. "There is an increasing demand for the outserts in particular," explains Dieter Sensmeier, who manages the printing shop. Turnover has increased by a total of 85% since 2006, and this has meant that the printing shop's capacity requirements have also increased. Both the fleet of printing presses and the corresponding compressed air supply have been upgraded. Quality and reliability are particularly important on both counts. Since autumn 2011, Bähren has been using three compressors from Atlas Copco Kompressoren und Drucklufttechnik GmbH.

New Printing Press Requires a Completely Different Compressed Air Supply

Bähren has purchased a new folding machine every year since 2010. At the end of 2011, the company also invested in a state-of-the-art printing press that meets the particular requirements presented by lightweight paper printing. The new press generates less noise and heat in the hall, and can save a large number of programs. However, the new system also required the central compressed air supply to be adapted quite considerably. The two old 7.5 kW compressors that had previously provided the company with its entire compressed air supply did not meet these requirements. Moreover, both compressors would have needed a general overhaul, which would not have been economical. On the recommendation of another printing shop, the company turned to Atlas Copco Kompressoren und Drucklufttechnik GmbH in Essen, Germany, and has been in safe hands ever since. The printing shop now has a total of three Atlas Copco compressors, of which two supply the network — one GA 37+ FF and one speed-regulated GA 45 VSD FF, both with refrigerant dryers installed (FF stands for "Full Feature"). The network delivers virtually oil-free compressed air to the Piab system of the new printing press at a pressure of approximately 6.5 bar. The GA machines compress the air using an oil injection system, but Bähren requires oil-free compressed air. However, this is not an obstacle: "The filter combination and separators work extremely cleanly!" in-house engineer Jürgen Schophoven confirms.

Compressors Supply the Piab System

"Our contact person at Atlas Copco had pointed out to us that we would in all probability not require as much compressed air as the three compressors are currently delivering," said Schophoven. And he proved to be right. "Nevertheless, we upgraded from 15 to 112 kilowatts. The manufacturers of printing presses were insisting on this capacity in order to guarantee that the machine would continue to function smoothly." At the moment, however, one of the two compressors is sufficient, meaning that only the GA 45 FF VSD (Variable Speed Drive) normally runs for the 6.5-bar network, the GA 30+ supplies the 12-bar network and the GA 37+ FF replaces one of the two other compressors alternately. The company is pleased with both the new compressors and the collaboration with Atlas Copco. They believe that the level of service is appropriate and the advice received is good — and ultimately, the price was right too.

Nothing Works without Compressed Air

The system is also designed to allow the compressors to be swapped over in some cases. The GA 37+ FF can therefore be switched flexibly between the two compressed air networks. If there is a crash, it would be possible to restart the entire system within 15 minutes. Nothing works without compressed air at Bähren — the control technology, printing presses, folding machines and rewinders would be at a standstill if the compressors failed to run reliably.

Water in the Pipes Had Caused Problems

The top priority is therefore to ensure that the compressors work absolutely safely and reliably, and no compromises are made in servicing the machines either. Bähren has also purchased the maintenance service for the new machines directly from Atlas Copco, as servicing will be performed by trained specialist personnel. Everything is currently working perfectly: The refrigerant dryers and filters installed in the compressors deliver oil-free, dry and clean air; a few dead sections were removed from the pipelines, while other branches were modernized using high-quality aluminum pipes from the AIRnet system from Atlas Copco. "However, we believe that there are still possibilities for optimization", Sensmeier explains. One plan for the future is to replace the old copper pipe network completely with AIRnet pipes.

Heat Recovery and Further Optimization

Bähren is planning further improvements for the future, such as a heat recovery system. The hot water from the cooler could then heat a hot water reservoir via a heat exchanger, and this hot water reservoir could then be used to heat the hall. To date, all compressors have also run without a higher-level control system. Colleagues at the company have agreed that there is certainly potential for improvement here, in terms of the amount of energy used to generate the compressed air. "At the moment, though, we don't have the time to implement all our plans — for the very reason that we first need to complete the large number of orders we have received," Jürgen Schophoven says with a grin. The large volumes of air to be supplied are incidentally also not a problem for the thriving printing shop. The company is well prepared for the future — a new hall will be connected to the compressed air supply within just a few weeks.