Application of RFID in the food industry

Chocolate production process

The production process of sandwich chocolate is somewhat complicated. The first step is so-called mold injection molding, where the molds are loosely placed in the supply chain and their "journey to the production floor" begins. Molds will begin their journey by moving intermittently or continuously depending on the supply chain's operation.

Once the mold has been sufficiently heated by hot air or infrared rays, the first depositing machine pours a precise amount of chocolate syrup into the mold to produce the candy shell. The mold is then shaken to evenly distribute the syrup, eliminating air bubbles. Then, the mold is turned upside down to separate the chocolate shell from the mold while cooling. The so-called chocolate shell is left in the cooling container to harden.

The second step of the pouring line provides typical fillings such as buttered almonds or soft syrup. The principle is the same: heat, fill, cool. The chocolate candy's smooth base - or "lid" - is created by melting and removing excess syrup, and finally cooling it. At the end of the production line, the candy is peeled out of the mold by gently tapping the back of the mold with an air hammer. The conveyor belt brings the finished product to the packaging line, while the molds are left in the chocolate production cycle. They are sent to the mold transfer station to remove residues and become new empty molds for use. The entire system is controlled by PLC and servo motors, and PC control terminals or customer service terminals connected to the central server are located throughout each pouring machine.

All molds are visible at a glance

Considering that the processes and sequences of many production industries are optimized and managed by non-contact RFID transponders (tags), WDS decided to also introduce this innovative NFC (Near Field Communication) technology into its candy product production line.

In order to complete this project, thousands of plastic pallets in the production workshop were equipped with RFID tags. The read-write heads on the production line, as well as the remote data collection systems in the warehouse and production areas, are permanently installed, so that each mold can be effectively tracked by the central control station during system operation. Database-oriented RFID systems ensure optimal tracking of molds and products during the production process, in addition to optimizing processes and aiding in production data analysis.

RFID experts from Mulheim, Germany, integrated IFAST's read-write heads into the fieldbus system through the BL ident I/O module, so that the WDS control system can view the latest data at any time to achieve real-time monitoring. Read/write heads are installed on mold transfer stations and pouring/sedimentation machinery, and optionally on weighing and other control links.

All data collected by the control system is transmitted to the local database of the factory server, where real-time data of all molds throughout the production cycle is Stored. The information is generated synchronously through the server and used for the overall management and tracking of the mold. A complete RFID system includes not only reading points on the production equipment, but also reading heads in the mold cleaning station and reading heads in the storage system. In accordance with the customer's wishes, WDS allowed a third party to retrofit its old system with IFAST RFID products.

High value-added data

Today, IFAST's RFID system ensures that each WDS device's central server database contains valuable information that they can use to optimize factory production and product quality. Possible applications for data pools are wide ranging, including optimizing logistics. With a gentle click of the mouse, the system can display the real-time position of any mold, or its running trajectory on the entire assembly line. This way, potential sources of errors can be easily targeted.

Application of RFID in the food industry

Production-specific data can also be determined from this. For example, the system can detect excessive residue content in a single mold or even an entire mold group and then automatically sort it out. Another application is the ability to compare the production characteristics of mold sets and specific batches.

The data pool is also very useful in quality control and hygiene supervision within the factory, especially in terms of quality management. The system can easily identify whether the current production process is clean or not. Currently, the system can track production procedures at close range, such as pushing molds collectively into freezers, or replacing molds with special test molds during system operation, all thanks to RFID technology. If the inserted mold is not suitable for the currently running production process, the system immediately issues an alert. "Rapid" product changeover is also possible with this technology: as old molds are picked out, new molds are inserted into the system. Even production schemes in which mold sets are randomly mixed are possible, thus increasing production flexibility.

win-win

"Among a number of competitive similar products, we finally selected IFAST. The BL ident system provides hardware with standardized interfaces suitable for industrial sites." explains Bernd Plies, head of electrical Engineering and automation technology at WDS, " Our choice to combine the RFID system with bus systems such as Profibus, DeviceNet and modbus IP, the various bus protocols currently used in our production halls, was successful and is also suitable for future bus systems.” Another important factor is Read-write heads have broad application prospects in the industrial field.

As expected, the system integration within the factory was ready to go live and no issues were discovered. "The system ran very smoothly and smoothly," Plies recalled. "All components were quickly integrated into the first WDS application, and debugging of Step 7 was realized. One or two problems would arise, but communication over the phone was quick. It’s all solved.”

According to Plies, another advantage of this project is the close cooperation between the two companies: "Working with IFAST is always constructive." IFAST's technicians are innovative and try to translate customer expectations directly into practice Or develop alternatives. “We benefit a lot from maintaining close contact with the R&D staff at IFAST,” adds Plies.