Vacuum technology helps beef stay fresh for longer

Variable-speed vacuum pumps from Atlas Copco are used to create vacuum conditions at two central stations on packaging lines at Tönnies Beef, saving energy in the vacuum-packing of the cuts of beef in thermoforming and shrink-wrap machines.

The Tönnies Group has built its bovine animal competence centre in Badbergen, Lower Saxony. What used to be a mixed slaughterhouse has become a ‘bovine animal competence centre’. For decades, cattle and pigs were slaughtered and butchered at the same time in Badbergen on behalf of other companies. In 2017, the Tönnies Group took over the site and decided to base its entire slaughtering operation in Badbergen.

In 2020, Tönnies Beef reopened the site after extensive conversion and renovation. The Group invested around 85 million euro in the building and state-of-the-art technology at this site. The slaughtering, butchering and finishing processes are based on the latest cooling technology, machine-based butchering and highly automated picking and shipping lines.

Several hundred tons of meat leave the site every day and 95% of the animal – practically everything – is utilised. This allows Tönnies to satisfy different eating habits around the world: while German consumers prefer lean beef, meat with a thick layer of fat is popular in Scandinavia and other European countries.

“The cuts weigh between 1.5 and 9 kilograms after butchering,” explains Waldemar Metzger, technical manager of Tönnies Beef in Badbergen. The cuts are vacuum-packed for various major customers. For this purpose, Tönnies has installed several packaging lines in the halls: seven thermoforming roller machines and two robot-operated shrink-wrap packaging machines. Efficient 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 really fresh. They work in two stations and supply forming, low and fine vacuums.

The thermoforming machines 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,” explains Metzger. “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,” says the technical manager. After filling the shell with smaller pieces of meat, the shell is ‘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

Metzger has been working in Badbergen for 20 years and has been part of the planning and execution stages of converting the mixed slaughterhouse to a purely beef operation from the very beginning. This included the decision to purchase Atlas Copco variable-speed vacuum pumps. “As far as technology is concerned, being able to vary the speed of the GHS vacuum pumps is essential to us and saves energy,” he stresses. “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 often required when using central vacuum systems.