Outstanding Contacts: Slip rings for packaging, filling and labeling

Resealable sausage packages, a zipper on the grated cheese bag, orange juice pockets with screw caps or PET instead of glass: all these innovations are intended to make our lives easier. The packaging industry is currently undergoing profound changes, which are affecting entire areas of the automation sector. Slip rings transmit here all important information, signals and loads with highest robustness and long service life.

Packaging machines work at ever faster speeds, ever more compressed cycles and provide - in ever shorter intervals - new products. Today, packaging manufacturers produce many - sometimes extravagant, sometimes ecological, but always highly functional - variants in size, material, color or shape. Flexible automation helps them to produce even more efficiently and economically, in spite of the increasing individualization.

While in the 1990s, a serial robot managed to handle a packaging volume of 47 pieces of chocolate per minute, a so-called parallel robot is packaging today up to 130 pieces of the same product. And, in addition, it is generally more affordable. In view of the ever growing mountains of rubbish - the whole of the packages represent worldwide almost a third of all the waste produced - both the materials and their quantities have to be rethought.

Today, on a packaging machine, the more tool setup and change are flexible, the greater the environmental benefits. Because, in this case, flexibility means creating possibilities to use for individual products exactly the quantity of material they require.

The function of slip rings

With its wide range of slip rings, Kübler offers extensive support for the complex process chains of the packaging industry, from the flow pack machine up to bottling or labeling plants. This includes an innovative contact technology as well as reliability or the cost savings topic both in operation and during erection and servicing.

Slip rings allow transmitting power and electrical signals from a stationary to a rotating element and vice-versa. This technology is typically used in rotary tables or in industrial robots that have to repeat their moves and tasks millions of times with a durably constant accuracy. So slip rings use for example coating systems containing precious metals, which have a high wear resistance. Combined with a wide variety of contact materials, this ensures trouble-free signal and current transmission and prevents the formation of oxides or corrosion.

Flow-pack machines

This trend is also clear in flow pack machines: less is more. Innovative lightweight films are weighing up to 40 
percent less than their conventional counterparts. Also novel flexible vacuum films used as a two-chamber solution keep food fresh for longer; in addition, innovative adhesives contribute in improving durably the ecological footprint of the tubular film packaging.

Flow pack machines are used mainly when a particular high packaging density and stability is required, such as in the food industry or in the medical or pharmaceutical technology. Plant competitiveness is ensured by high speeds, low maintenance costs, long service life and particularly hygienic cleaning possibilities in compliance with the GMP or with the EcoLab standards. Therefore, the design concept of the plant must be oriented towards productgentle, accurate and trouble-free processes. The suitable slip ring for this application must feature high rotary speeds, high load current and particularly low-wear contacts.

The slip ring generation SR060E has been designed especially to meet these requirements. With up to three load and two signal channels, this series is designed for a load current up to 20 A, therefore standing out with short heating times. Thanks to the fully encapsulated housing with a two-chamber system, it is in the same time safely protected against touching and humidity, perfectly insulated and particularly easy to clean.

Moreover, this slip ring features all relevant characteristics to meet fully the strict hygiene and cleaning safety requirements in aggressive environments. So the corrosion-resistant oval housing with IP64 protection level withstands easily the regular cleaning of the machine, even when using aggressive detergents and disinfectants.

Bottling and labeling plants 
 
If the products are similar, the difference must be made by the packaging. Trouble-free filling and labeling can be achieved with low maintenance and a high service life and reliability of the components. With its non-contact signal transmission, the slip ring SRI085 has the answer also for the safe transmission of even high data rates in large and medium-sized carousels. It operates almost maintenance-free even in case of durably high rotary speeds.

Thanks to the separation of data and power transmission, the modular subsystems can be adapted individually or in combination according to the requirements. Up to 20 channels can be achieved; the good insulation moreover ensures a particularly low contact noise. A stainless steel version has been developed especially for use in the food processing sector: thanks to its smooth and round design, the SR160, available either for encoder connection or for air connection, offers no surface where dirt could accumulate.

The material features protection level IP65 and a particularly high-grade sealing technology; it withstands even highly aggressive detergents and makes the slip ring a real packaging artist.