Foodstuff packaging machines must work fast, reliably and in perfectly hygienic conditions. Extremely low-maintenance slip rings ensure in the same time cost-effective operation.
One of the most important processes, mainly in the food industry, is the wrapping of the products in a suitable packaging. The packaging does not only ensure hygienic food protection against dirt and spoilage for long periods of time, it also helps preserving the shape, the colour and the taste of the products. Furthermore, optimal packaging contributes to the reduction of the additives used with the food, such as for example for its preservation.
In addition, printed film packaging for example supplies the consumer with important information about product features, nutritional content and ingredients of the packaged food. And, last but not least, the packaging also allows a salespromoting presentation of the products at the point of sale.
High hygienic requirements
However, all these advantages can be implemented only if the packaging, in addition to meeting the product requirements, also complies with the extremely strict standards and hygiene rules of the Regulation on the hygiene of foodstuffs. These rules do not only apply to the finished product, but to the whole manufacturing process, including the packaging machines, their components and all of the materials used during the production.
In his Transmission Technology products range, the encoder and counting technology specialist Kubler from VillingenSchwenningen offers, specially for the transmission of energy, signals and data between stationary and rotating components, the slip ring SRI085 and the brand new model SR060E. These robust devices resist reliably the harsh conditions of the working environment of food packaging machines and ensure reliably smooth functioning and long service life; this applies to the material of the drive unit as well as to all interface components such as connections and seals.
The new slip ring SR060E is designed for up to 3 load and 2 signal transmissions and shows its strength in many different applications: from heating and monitoring of the sealing rollers in flowpack machines, in stretch film wrapping machines or balancing machines, and up to textile machines.
Both models feature a fully encapsulated housing with a two-chamber system and are therefore in the same time safely protected against contact, perfectly insulated and particularly easy to clean. So the Kubler slip rings have all essential features to meet the hygiene and cleaning safety requirements in aggressive environments. For example, the corrosion-resistant oval housing has an IP64 protection level; its smooth surfaces, without undercuts, facilitates the regular cleaning of the machines with aggressive detergents and disinfectants required by the Regulation on the hygiene of foodstuffs.
The fully encapsulated housing also safely protects the food to be packaged from escaping abrasion dust or lubricants that might be harmful to health or have a negative influence on the taste or smell during the production process.
A trend in mechanical engineering is the increasing maintenance optimisation with the goal of building plants requiring particularly little maintenance or even no maintenance at all. The contact material used in the Kubler SR060E slip ring, with contacts out of gold, silver, bronze and precious metal supports this trend: the slip ring requires minimum maintenance only all 100 million revolutions, simply consisting in vacuumcleaning the dust.
Even in the case of continuous operation, which is generally the case today with this kind of machines, this value is practically negligible. The slip ring SRI085 relies on contactless signal transmission to the moving machine parts; it operates totally without mechanical wear.
With their high rotary speed of 500 or 800 revolutions per minute, the slip rings suit optimally the use in packaging machines: the increasing production capacity of packaging machines in all areas, not only in the food processing industry, leads to increasing products speed on the conveyors.
This fast pace results, for example for heat-sealing of blister packagings, in increasingly short contact times for the films. For these cases, the dimensioning of the Kubler slip rings for load currents of 20 resp. 25 amperes allows very short heating times and thus an optimal temperature regulation even for shortest contact times The installation using flat plugs, fastening screws and anodised aluminium parts minimise the start-up time.