The Kallfass Packaging Machinery Company in Nürtingen near Stuttgart, are specialists in high speed packaging machinery. Their machine designs put reliability and availability with minimum down times at the top of their list of priorities. Their fully automatic side sealer machine features a particularly sturdy design where Lenze frequency inverters and geared motors are used for the film transport operations which requires accurate indexing at up to 85 operations per minute.
The Universa 400 packaging machines offer fully automatic overwrapping and edge heat sealing without film overlap. Products of randomly varying lengths can be packed with speeds of up to 85 packs per minute. The products are fed in via an in-feed conveyor and at the same time are wrapped in a centre-folded film by means of a forming shoe. After wrapping of the product in film, the cross seal is made with a permanently heated sealing system and excess film is cut away with a knife. The Universa 400 machine is highly flexible with sealing widths of up to 450mm. It is capable of sealing practically any product, for example video cassettes, shower gel, paper plates, pet food and even long wooden panels (several meters in length).
Contracting packaging companies in particular need machines that can be quickly converted for new tasks. That is why the Universa is equipped with an integrated product data memory which keeps changeover times to a minimum, thus ensuring higher productivity. The integrated product data memory can be used to store up to 250 different products for packaging. The data stored is not merely limited to the format, but also includes the seal bar temperature, sealing times or temperature of the downstream shrink tunnel.
Using software on a plc machine control system with PROFIBUS communication, it takes only a fraction of a second to switch drive parameters. Lenze 8200 vector inverters control the film feed, and these inverters are equipped with two parallel communication interfaces into which optional communication modules are plugged. They include an integrated RFI filter compliant with Class B levels and occupy a minimal amount of space. Easy plug-in connections are provided with large surface special shield sheets for optimum EMC behaviour. The 8200 Vector range covers powers between 0.25 and 90kW with an overload capacity of 180% rated torque.
In the case of the Universa 400, the Lenze helical geared motors for variable speed operation are equipped with incremental encoders for closed loop feedback, connected into the plug-in I/O module on the frequency inverters. According to Tino Kraut, Technical Director at Kallfass, the degree of speed synchronism thus achieved is sufficient to ensure the level of accuracy required by the machine. Therefore the company has decided that there is no need to use servo technology to transport the product through the machine.
Some 60% of Kallfass machines are exported, principally to Europe and the USA. It is vital to the success of the machines that they meet the key criteria of robustness, straightforward operation, reliability and long life time. The machines themselves are supported by an international service network. Packing companies working around the clock on contracts need to know that their packaging systems offer maximum availability. That is why Kallfass offers a modem connection with its machines. In this way customers can opt for round the clock remote maintenance. Lenze support this with an internationally available freephone expert help line and remote maintenance modem options for its drives.
Kallfass and Lenze have been working closely together for almost 10 years. “The price and performance ratio of Lenze products is just right”, explains Tino Kraut. It is the aim of both companies to achieve a competitive edge and productivity gains by ensuring appropriate functionality, top quality, high availability and innovative concepts.