A lean cutup

March 2015

 

The new slicer built by VC999 cuts cheese and cold cuts exactly to the gram and saves lots of space while doing so. Rexroth drive technology has considerably reduced the size of the switching cabinet.

Sometimes every gram is important. In the refrigerated display case, for example. If pre-packaged sliced cheese or cold cuts should weigh more than what is posted on the package, then the customer is more than happy. But not the manufacturer. Because, all in all, he earns less. According to law, each 100-gram package, for instance, does not have to contain the stated weight. But that average minimum weight has to be maintained throughout each lot. With its processing and packaging line, Swiss manufacturer VC999 ensures that this is exactly what happens. “Our systems deliver mean values of about 100.05 grams,” reports sales manager Manfred Achenbach, “and that at very high throughput.” In the newest cutting system, the SL600 slicer, bulky switchgear cabinets were also to be eliminated as far as possible. That is why the machines built in the town of Herisau shine with a new concept: Every drive carries its own control electronics – piggy-back. That not only reduces the volume of the switching cabinet. It also simplifies installation and retroactive expansion of the systems. That cuts costs.

Clever drive solution trims space

The decentralized IndraDrive Mi servo drive made by Rexroth significantly reduces the space required for the drive technology in the machines. Since the control electronics “ride” on every drive, the resulting unit is compact. And moving it out of the main switchgear cabinet makes that unit smaller, too. This arrangement not only saves space but at the same time simplifies assembly. Up to 30 IndraDrive Mi units can be connected, one behind the other, along a 200-meter run of cable.

Depending on the connected load, the length of the cable and the options selected, linking even far more drives in series is possible. The assembler simply connects the next one, using a hybrid plug, to the neighboring IndraDrive Mi. This also simplifies expansions to the system. If, for instance, labels are also to be applied to the packages, the additional module is mounted and plugged in. It’s just that simple! Traversing the SL600 slicer is a hybrid line for power, communications and safety. It starts at a small switching cabinet and is looped through the connected controls. The controls and the drive for the slicer blade head are also included there. Thanks to the new power and supply modules in the IndraDrive Mi family it is even possible to configure the machine without any switchgear cabinet at all. “We need less cable, save space, and reduce the installation effort,” states Achenbach.

The new system is also thrifty in its energy consumption, too. The energy generated during braking is not lost. Instead the system uses it to accelerate the drives. That improves energy efficiency and simultaneously reduces the amount of heat emitted into the production hall. This plays an important part in the foods industry in particular.

A quick cut

The SL600 can turn out up to 3,200 slices of cheese or cold cuts every minute. To do that, the automation technology has to accomplish quite a lot. That is because speed, short set-up times and exact positioning right down to fractions of a millimeter are the primary demands of foods manufacturers. To achieve this, VC999 operates closely with the application engineers at Bosch Rexroth. “The joint development project was faced with the challenge of bringing great dynamics and precision into line – and to do that across all the individual modules and, what’s more, in synchronization,” notes Achenbach.

Precisely poised for slicing

To ensure that precisely cut slices land in the packaging at the end of the line, the cheese and cold cuts have to be positioned at the cutting blade with a highly precise feed mechanism. This is particularly important when loading a new piece of cheese or sausage. An in-line sensor adjusts the weight of each portion to suit. The FlexProfile functional package provides the needed dynamics and here VC999 programs the electronic cam disks. “Not many drive manufacturers can achieve this degree of precision and dynamics in all sorts of operating modes,” Achenbach emphasizes. The advantage of the Rexroth solution: Instead of using static points along a physical cam, the software considers a large number of laws of motion and transitional conditions to form profiles. These are then stored in the controls.

Simple utilization

Many complex processes – and the operator is hardly aware of them. He runs the machine simply and intuitively, using the new IndraControl V control terminal with multitouch features. “Simple operation makes for good results,” emphasizes Achenbach. In concrete terms this means: Thousands of precisely cut slices of cheese and sausage – in a space-saving machine and exact to the gram.

IndraDrive Mi

With its IndraDrive Mi concept, doing away with a switchgear cabinet, Rexroth not only offers to machine constructors and users a system featuring maximum flexibility and efficiency. It also revolutionizes the engineering of packaging machines and boasts impressive facts:

  • Reducing the size of the switchgear cabinet by up to 90 %
  • Reducing cabling and installation effort by as much as 90 %
  • Reducing energy loss in the switchgear cabinet by up to 90 %

How is that possible?

The fundamental concept behind IndraDrive Mi is merging the drive electronics and the motor to form an integrated unit. The next development stage for this innovative drive platform was introduced for the first time at the 2014 interpack. The concept consistently eliminates the line power components currently found in the switchgear cabinet (power supply units, contactors, EMC components).

The result is an evolution in the revolution:

0% switchgear cabinet, 100% flexibility.