CONTROL AND DRIVE TECHNOLOGY Packaging experts: robust and reliable encoders for packaging machines Dieter Schömel Foodstuffs must be packaged securely in order to reach consumers in undamaged condition. Econo-Pak is a company with machines specialized in this task. Their solutions are used worldwide. Robust and reliable encoders by Wachendorff met the quality requirements of the packaging machine manufacturer. Ice cream, biscuits or dishwasher tablets are usually found on supermarket shelves in colorful folding boxes. These days the automatic machines that place the finished products into these boxes are an important and accepted component of production lines. They are particularly common in the food industry: Goods cannot be temporarily stored – at the end of the production process they are generally packaged as they are then received by traders. This isn‘t just sensible for logistical reasons – hygiene and product quality also make rapid packaging of the goods a requirement for their protection. Focused on quality Author: Dieter Schömel, Produktmanager, Wachendorff Automation Operational safety plays the most important role in this industry as every standstill has a significant effect on quality and can even render the goods unusable: “Our customers need machines that are
CONTROL AND DRIVE TECHNOLOGY safe and reliable,” explains Markus Zerbe, National Distribution Manager of Econo-Pak. The family business, which has been developing and manufacturing packaging machinery in Rhineland- Palatine in Germany since 1985, is therefore focused on absolute quality and places high demands on their suppliers. “We need real ‘Plug and Play’”, says Ralf von Landenberg, responsible for machine electronics. “The components must be easy to install and integrate and then function - preferably without maintenance, laborious adaptations or even stoppages!” Precise under harsh conditions Von Landenberg has been using Wachendorff encoders for over 10 years. The WDG 58 D with 720 pulses, which separates the production process into various substeps, is primarily used. The position of the encoder provides the machine control with precise information on which part of the process the cardboard packaging is currently in - whether they are in the correct position to be folded, or whether they are in the right position in order to apply the adhesive for sealing. The encoder used by Econo-Pak is the most resilient in the Wachendorff range - for good reason: “The environment is very harsh in our industry - for frozen products, for example, it’s not just the extreme temperatures but also the high humidity that affects all machine parts,” relates Ralf von Landenberg from his experience. The cleaning materials are also often very aggressive. “One of our customers in the USA lathered an entire machine overnight. The motors didn’t survive but the Wachendorff encoders still worked,” he explains with a grin. Tested to the limit The encoders determine the exact position of the cardboard packaging; their pulses provide information to the control on when the next process substep can be triggered The encoder’s electronics and coated aluminium housing with protection class IP 67 isn’t just well protected against extremely low temperatures of up to -40 °C and corrosion: The radial and axial bearing load can also withstand up to 400 Newton. This robustness of Wachendorff components is no coincidence: All encoders are subject to load tests in the manufacturer’s internal laboratory. For example, all encoders are exposed to severe vibrations for at least 300 hours in a special shaker and the shock values on all axes are examined 1,000 times. Anything that does not pass the tests is removed and replaced by other solutions by the Wachendorff developers. The molding of all larger components and the cable connections on the circuit board also ensures robustness – this means that everything stays in place and securely connected even in the event of strong vibrations. In addition the temperature range is examined in a climatic chamber, where extreme fluctuations within short time spans are simulated. “We previously had problems with condensation that caused stoppages”, recounts von Landenberg. “Everything has been operating reliably since we started using Wachendorff products. We haven’t even experienced discarded shafts since then.” “We’ve actually stopped thinking about the encoders – they are cost-effective and we know that they work. We certainly won’t take the risk of changing suppliers,” von Landenberg gives Wachendorff the best compliment that a manufacturer can hope to receive. Photographs: Teaser and 01 Econo-Pak, lead Wachendorff www.wachendorff-automation.com About Company name: Wachendorff Automation GmbH & Co. KG Established: 1978 Headquarters: Geisenheim, Germany Turnover: € 15 m (2014) Employees: 80 Products: encoder, motor feedback systems, … AUTOMATION TECHNOLOGIES 3/2015
