"First and foremost, our customer wants a securely bolted drum," says Mathias Mente. He is Technical Manager at Feige Filling in Bad Oldesloe and knows what his customers want. These include food processors and the mineral oil industry, as well as chemical manufacturers who cannot afford leaking containers under any circumstances. "Imagine if the seal on a container with highly toxic contents were to leak during overseas transportation. That could contaminate an entire cargo ship." To prevent this from happening, Feige Filling develops and produces filling solutions that eliminate such risks as far as humanly possible.

Mathias Mente, Technical Manager at Feige Filling: "We build more than 100 filling plants and systems every year in which high-torque special motors from Atlas Copco reliably perform their screwdriving tasks."

"Of course we are feeling the current price pressure in the bottling industry," admits Mente. However, the company offers customers individual solutions in terms of safety and efficiency. With over 100 systems delivered and commissioned worldwide every year, the company is one of the market leaders in Europe. Closures, seals, materials and manufacturing tolerances - everything varies with almost every batch of containers. The range of containers is becoming more and more colourful, Mente comments on globalization. Depending on the market, different specifications, guidelines and production qualities have to be adhered to. "This constantly confronts us with new challenges, which we are sure to overcome."

Problems due to incorrect savings

Using the example of a supposedly simple 200-liter steel drum, Mathias Mente explains why it is not so easy to screw these containers together correctly: "Some customers use a polyethylene sealing ring for the threaded plugs instead of an elastomer seal, partly for cost reasons. However, many users do not consider the fact that this other material begins to flow under the force of an applied torque and that the closure system then has a completely different setting behavior." And if that alone were not enough, some of his customers' factory standards specify torques of 25 Nm for one and the same closure, while others specify torques of up to 60 Nm.

Feige Filling strives to meet all market requirements. To this end, the company works closely with its suppliers. Feige uses a special high-torque motor with an LZB33 planetary gearbox in its Advanced Line systems. Atlas Copco Tools developed this specially two years ago. "We install two in each of our filling systems," says Mente. Due to the limited space available, Atlas Copco designed the sealing cap for the output shaft so that the motor can be integrated directly into the screwing mechanism - without an additional connecting flange. In addition to the space-saving design, Mathias Mente emphasizes that the LZB-33 motors are very flexible in terms of torque and speed and always screw the plugs in correctly.

"The first LZB 33 unscrews the stopper from the empty drum. While the open drum is cycled into the filling station, a small belt conveyor transports the unscrewed metal plug to the capping station," explains the technical manager. There, the incoming freshly filled drum is centered again. The second LZB then screws the closure into the bunghole with the exact torque required.

What does "exactly" mean?

These steel sealing plugs are screwed into the Advanced Line filling systems from Feige Filling GmbH using Atlas Copco motors. The trick is in the detail: even changing the sealing material from elastomer to polyethylene makes it necessary to screw in the closures in a completely different way to ensure that the drums are tight. (Image: Atlas Copco Tools)

The customer can decide exactly how "precise" they want it to be. Feige Filling offers three options for torque control: "We can end the actual screwdriving process via a mechanical cut-off using a spring or back-pressurized pneumatic cylinder," says Mente, describing the more classic options. Although this already meets the requirements of the relevant guidelines, "we recommend the use of load cells as a third variant, in which a lever mechanism defines the torque more precisely and enables electronic monitoring and documentation of the screw-in results". The LZB high-torque motors, which can also be operated with oil-free compressed air, are exactly the right choice for this application. This is because their robust planetary gears can absorb higher stall torques without being damaged.

High-torque air motors from the LZB-33 series (the black cylindrical system component at the top of the picture) deliver up to 2.9 kW of power to the shaft via their inline planetary gearbox. Almost all drives in this series can be operated with oil-free compressed air. Depending on the application, they are also available with ATEX certification for use in potentially explosive working environments. (Image: Atlas Copco Tools)

According to Atlas Copco, the low-speed LZB-33 high-torque models with idle speeds between 14 and 210 ^rpm cover nominal torques of 36 to 300 Nm. Under load, they consume only 7.9 to 8.1 l/s of compressed air according to factory specifications. This is now another criterion for many customers, says Mente: "Compressed air used to be seen as an energy source that was available per se," he recalls. "Today, however, the demand values of the air consumers are increasingly being included in our customers' profitability calculations." And he emphasizes another aspect of economic efficiency that is at least as important - durability: the internal sealing towards the gearbox is better solved with the Atlas Copco motor than with a model from another manufacturer that was previously installed. "It was possible for residual moisture from the expanding compressed air to condense in the gearbox," explains Mente. "This caused the drive to wear out prematurely and, in the worst case, could cause production downtime for customers." This problem does not exist with the LZB-33 models now in use. "Since we switched to the Atlas Copco motors over a year ago, we haven't had a single complaint." cs