Keeping beef fresh using central vacuum stations

German-based The Tönnies Group’s cuts of beef are vacuum-packed in thermoforming and shrink-wrap machines. The process is now more efficient thanks to a renovation at its facilities where Atlas Copco variable-speed vacuum pumps are now used to create vacuum conditions at two central stations.

Previously, The Group slaughtered and butchered cattle and pigs at the same time on behalf of its other companies. It has now invested around 85 million euro in its new ‘bovine animal competence center’ in Badbergen, Lower Saxony. The slaughtering, butchering and finishing processes are based on the latest cooling technology, machine-based butchering and automated picking and shipping lines. Several hundred tons of meat leave the site every day and 95% of the animal — practically everything — is used.

“The cuts weigh between 1.5 and 9 kilograms after butchering,” explained Waldemar Metzger, Technical Manager of Tönnies Beef GmbH & Co. KG in Badbergen.

The cuts are then vacuum-packed for various customers using several packaging lines in the halls which have seven thermoforming roller machines and two robot-operated shrink-wrap packaging machines. Atlas Copco vacuum pumps are used in the systems to vacuum pack the tubular/shrink bags and thermoformed plastic trays, and to keep the meat fresh. They work in two stations and supply forming, low and fine vacuums.

The thermoforming machines are supplied by vacuum station 1. There are four Atlas Copco GHS 585 VSD+ variable-speed, oil-injected screw vacuum pumps that evacuate the air up to 40 mbar (absolute), as well as four small boosters that lower the pressure even further to 3 mbar. One of the screw pumps supplies the forming vacuum for the thermoforming roller machines, which only require around 100 to 150 mbar for the forming process. The other vacuum pumps in this station are connected to the boosters.

One of the pumps is redundant at any given time: this is also the case in the second vacuum station, which comprises five GHS 730 VSD+ pumps that remove the air from the shrink bags at the Cryovac lines.

“The size of the cuts of meat is automatically detected by our systems,” Metzger said.

“The packaging machines then automatically insert the cuts of meat into the tubular bags, which are cut to the correct size under a vacuum bell.”

Under the hood, all ambient air is then evacuated in two stages until the pressure is around 3 mbar (fine vacuum).

“With the forming vacuum — or thermoforming vacuum, as it’s also called — the plastic tray is formed by cutting the foil roll,” Metzger said.

After filling the shell with smaller pieces of meat, it is then ‘wed’ to the cover film: the tool closes and seals the packaging airtight at 3 to 5 mbar using the fine vacuum.

Sorting machines assign the individual trays and tubular bags to larger boxes, which are then used to pick custom boxes for customer orders. Efficient speed regulation reduces energy requirements by a third or more.

“As far as technology is concerned, being able to vary the speed of the GHS vacuum pumps is essential to us and saves energy,” Metzger said. “Compared to fixed-speed machines, you can reliably cut down energy requirements by around a third — perhaps even by half, depending on the diversity factor.”

The controls on the vacuum pumps have a user-friendly plain text display, which also indicates the running hours and maintenance intervals. Since the Atlas Copco pumps can be connected directly to an exhaust system, it was possible to use air-cooled pumps.

According to the manufacturer, this improves the climate of the room; it is no longer necessary to have the additional room cooling that is often required when using central vacuum systems.

The project was implemented onsite by Oliver Hornberg, Managing Director of Eugen Theis Vakuumtechnik, which was sold to Atlas Copco in 2021.

Top image credit: Oliver Hornberg (left), Managing Director at Eugen Theis Vakuumtechnik in Werther, with Waldemar Metzger, Technical Manager at Tönnies Beef.