Quality Management in Pet Food Production with RFID!

Production Monitoring in Pet Food Manufacturing

RFID applications know no limits when it comes to the use of this technology.

The pet food manufacturer (hereinafter referred to as the "Manufacturer") specializes in the production of high-quality pet food. The product portfolio includes a wide range of wet food for dogs and cats, tailored to the specific nutritional needs of the animals. With more than xxxx employees, approximately xxxx individual recipes, exports to 50 countries, 2.5 million units produced daily, and regular safety and quality certifications, the Manufacturer is Europe's leading producer of premium wet pet food.

Production takes place on several state-of-the-art production lines for cans, pouches, and trays, which are divided into filling and labeling lines. At the end of a filling line, the filled and sealed products are collected in transport baskets. The baskets are then pushed into an autoclave (pressure vessel) together with the products, where they are cooked/sterilized. Afterward, the baskets containing the sterilized products are transferred to the labeling area, where they are unloaded and the products are inspected, labeled, and packaged.

In order to optimize the monitoring and control of these baskets and further increase the efficiency of the production processes, the Manufacturer plans to implement an automated identification system for the baskets containing the finished products.

Objective

The objective of the "Basket Tracking" project is the development and implementation of a UHF RFID-based identification system for the automatic detection and identification of transport baskets within the Manufacturer's production environment.

This system is intended to enable seamless tracking of the baskets from filling to labeling in order to optimize production processes and reduce susceptibility to errors. As part of a Proof of Concept (PoC), the feasibility of this technology will initially be evaluated.

Requirements

The following requirements arise in the course of implementing the project:

1. UHF RFID Tags

The transport baskets must be reliably detected by the corresponding readers at the respective stations (see requirements for UHF RFID readers).
The baskets must be equipped with UHF RFID tags that remain fully functional under extreme conditions (up to 150 °C and 3 bar pressure).
The RFID tags must be suitable for mounting on metal and remain readable after several thousand sterilization processes.
The RFID tags must be attached to the baskets using screws.
A suitable mounting position must be identified on the baskets that is identical for all three basket variants (cans, pouches, trays) and does not interfere with production processes or production staff during their work.

2. UHF RFID Readers

The stations for basket identification are autoclaves, basket loaders, and basket unloaders.
The readers and antennas must be permanently installed at each station and must not interfere with production processes or production staff during their work.
The readers and antennas must comply with at least protection class IP67.
The readers must be equipped with an OPC UA server that provides at least the UID of the most recently scanned basket/RFID tag per antenna.
RFID tags that do not belong to the respective station and therefore represent misreads should, where possible, be filtered out by the reader (e.g., due to insufficient signal strength, incorrect initial ID, etc.). Alternatively, filtering may be handled by the SCADA system. In this case, the OPC UA server must additionally provide the signal strength and specify a valid/acceptable signal strength range.

As part of the PoC, requirement 1.d does not necessarily have to be fulfilled. Testing different mounting positions on the baskets may be carried out during the PoC by bonding (or similar methods) the RFID tags to the baskets. The prerequisite is that the properties of the RFID tags do not change depending on the mounting method. In the event of a subsequent project award, a screw connection between the RFID tag and the basket will be mandatory.

If these requirements are met during the PoC and any subsequent project implementation by the contracted company, the work will be considered successful—i.e., the transport baskets can be reliably identified at the various stations. Any further steps following basket identification will be carried out by the Manufacturer's Digitalization Department. This includes, for example, linking the baskets to the respective production batches.

Production Process with RFID

The following illustration (Figure 1) shows a schematic representation of the production process. The stations and baskets to be equipped with RFID readers and RFID tags are highlighted in yellow and green.

For the PoC, several transport baskets, four autoclaves, and one basket loader will be provided for testing purposes.

Since the basket unloader is very similar in design to the basket loader, it is not mandatory to work on the basket unloader during the PoC. However, the possibility to do so remains

Proof of Concept

The challenge has been defined as follows: transport baskets are automatically conveyed through the company's various stations and must be detected at different points within the process.
In general, the data capture serves process optimization and quality assurance within the production process.
The required system represents a so-called closed logistics process, from basket loading through the autoclave to basket unloading.
Consequently, the transport baskets (together with the respective goods) must be individually identified and tracked throughout the entire transport chain.
RFID, as one of the most powerful technologies for contactless identification of individual items, represents the state-of-the-art technology for addressing this type of challenge.
RadioForce, with many years of experience in RFID applications, has been selected as the partner for the PoC in order to contribute its RFID expertise to this high-tech solution.

The Task

The task was defined in several parts:

Installation of the RFID tags at a position that is as consistent as possible across the three different basket types (cans, pouches, trays).
Temperature resistance of the RFID tags up to approximately 150°C.
Reading the baskets at various points within the transport flow at the specified locations without restricting the operational process. The read range must meet the on-site conditions (approx. 50–70 cm) and function reliably on a long-term basis.

In addition, it was required that the RFID system be integrated as seamlessly as possible into the infrastructure developed by the Manufacturer. The entire system structure consists predominantly of metal components (stainless steel).

This represents a major challenge for RFID technology. A Proof of Concept is required to develop the appropriate RFID solution for this type of application.

Various aspects must be taken into consideration, including RFID readers (fixed or mobile), antennas, RFID transponders, positioning, mounting, environmental conditions, and many other factors.

RFID UHF Components

RFID UHF Transponder (Tag)

The selection of transponders (hereinafter referred to as tags) depends on the various specifications required within the basket transport process. The autoclave conditions, read range, and the method of tag attachment are key elements of the desired functionality.

Naturally, a tag is required that provides excellent reading performance in this challenging environment.

From a selected range of different tags, RadioForce preselected three different tag types that meet the requirements.

In addition, RadioForce developed a mounting system that allows for easy handling after attaching the tags to the various baskets. However, this is not practical or necessary for this particular project. These developments were carried out in advance of the PoC.

Three different transport basket types:

Transport basket type: Can
Transport basket type: Pouch
Transport basket type: Tray

Conclusion

The PoC successfully demonstrated the required performance. However, further discussions and definitions are still necessary, particularly in the area of software integration. It is advisable to divide this project into multiple phases.

MA = Manufacturer
RFO = RadioForce

Phase 1:* Tagging – attaching the tags to all transport baskets → MA
Phase 2:* Pre-installation (Ethernet, 220 V power, antenna cables) → MA in coordination with RFO
Phase 3: Hardware installation → RFO
Phase 4: Software / Interfacing (requirements specification from LG required) → RFO and MA

*Phases 1 and 2 can be carried out in parallel.