Know How: Siwarex sets new standards for weighing terminals in spice factory

Clean and Tasty

Raps, one of the leading European spice producers, has combined an electronic weighing module with a load cell for its new, flexible dosing stations which requires no adjustment, has virtually no dirty edges, and which enables a variable platform size. The functional weighing terminal fully meets the high demands of food producing companies in every respect.

Raps produces more than 4,000 different spice mixtures and spice-related products for the meat and food industry, as well as for the wholesale gastronomy industry in its four spice factories in Kulmbach. Coated raw materials, known as “Coatec,” are one of the specialties of the house. Thanks to a protective film, the powders and crystals remain pourable, and do not become lumpy. Coating products are also of great interest for another market: namely, for use in marinated steaks such as those offered in butcher shops and supermarkets, especially during the barbecue season. Since every single grain of salt in the marinade is coated with a fine film of grease, the salt is prevented from drawing water from the meat. As a result, the meat quality remains intact over long marinating times. Flexibility is the key Since customer demand in this area has been particularly strong in recent years, demands on the filling process have also risen. Raps supplies precisely the package sizes the various manufacturers require for their production. Manual weighing processes are no longer necessary, and errors have been reduced to an absolute minimum. The filling plant in factory III, where the company produces more than 100 different spice varieties in a three-shift operation, was equipped with a modern, automatic dosing device last year. Since some products require only two hours, while others require a few days to produce, all of the systems are designed to allow for quick conversion. “We chose the module technology because it enables variable application of both scales on all sifting machines,” as Harald Schischeg, head of control engineering at Raps, points out. In addition to offering mobility, the solution had to be integrated into the control, designed as simply as possible, as well as enable calibration. The Raps spice factories expects that customers will want to see the weighing logs for their deliveries. Therefore, the company has also made archiving and recording a criterion for the filling.

The weighing system can be calibrated and parameterized via software, programming device or touch panel.   Competitively priced versatility Harald Schischeg was very impressed with the presentation of a new weighing module at Siemens. “As far as the electronics are concerned, the Siwarex FTA weighing module offers a lot of advantages. We can use it as a controller module in the distributed periphery. Since the weighing module is a S7-300 component, we do not need any additional interfaces either. Siwarex FTA also provides all of the weighing modes we need. In addition, the entire process, including the controller and Touch Panel TP 170B, can also be calibrated for legal-for-trade scales.” Adding to the appeal of the solution is the fact that complete calibration and parameterization can be variably performed either over the software, the programming device or with the help of the touch panel. The in-house control technology supplied everything that was needed for the mobile weighing terminals at low cost and from a single source, including everything from the design and the development to the software and hardware. Various challenges had to be overcome in the process. Every scale, for example, has to “know” which sifting machine it is linked to at any given time, and both dosing stations must be able to communicate with all of the four sieving machines. Also, tampering with the calibration display must be prevented at all costs. Harald Schischeg solved the complexity of the PLC program for the internal data flow with the help of coded, multifunctional Profibus plugs. The Profibus link is also one of the advantages of the implemented weighing module. The cable transfers the data to the Simatic ET 200M station. From there, they go directly to the Touch Panel. Everything is also prepared for activating the archiving and recording. The specialists at Raps have to change only a single bit in the controller programming. Mobile weighing terminals for various siftings systems offer a high level of flexibility during product filling.

The scale communicates with the Simatic ET200 station via Profibus, and from there directly with the touch panel. The entire weighing process is calibratable and tamper proof – a decisive advantage of the Siwarex FTA solution.   An amazingly simple solution The features of the Siwarex solution are ideally suited for the high hygiene standards of Raps, says Harald Schischeg: “In general, platform scales are very difficult to clean. The 652 platform cell typ consists only of a single piece of metal with a single external cable. It has a thread at the top and bottom so that a holder can be mounted on the bottom, and an appropriate plate on the top.” Since Siemens already specified the center of gravity of the Siwarex weighing system in advance, along with the maximum plate size, the correct basic loads are already ensured. The scales platform can therefore also be adapted optimally to the standard box sizes. The complete weighing terminal consists of one weighing sensor, one plate and a central display, and meets all hygiene requirements.

Find out more:www.siemens.com/weighing
E-mail: sigrun.ebert-heffels@siemens.com