SICK RFID tech used in automated tomato harvesting

Johannesburg, 12 Sep 2018
Read time 3min 40sec
RFID boosts tomato harvesting.

As technology improves, radio frequency identification (RFID) is increasingly being used for tracing foodstuffs.

Andreas Behrens, head of product management at SICK, a producer of sensors and sensor solutions for industrial applications, says implementing RFID is not uncommon in the case of large containers containing raw products and in the mixing of bulk materials.

"It offers companies a number of ways to streamline and manage their capacities, focusing particularly on the issues of traceability and process reliability. Using wireless technology for identification purposes opens up a new dimension in automatic data recording."

He says the automotive industry has been using RFID for years, where a tag is attached to the car body and is encoded with data options for each vehicle.

Because RFID tags are read/write devices and no visual contact of the tag is needed, they provide far better functionality than traditional bar code technology. In addition, they are highly robust, being able to survive harsh ambient conditions such as high temperatures, mud or wetness, Behrens explains.

Food and traceability

Kagome, a Japanese manufacturer and distributor of tomato-based foods, started using SICK RFID to ensure product traceability, which it said increased efficiency in its production processes at its Australian factory in Echuca.

Traceability has always been crucial for the food and beverage industry, and this has to start with accurate and fast identification, he says. "For many years, the identification workhorse has been the ubiquitous bar code. As foodstuffs move through the production process, they are identified by a unique code, on containers when in process, on packaging for the finished product, on cartons and pallets during transport and on shelves in retail stores.

Kagome, however, needed a real-time identification solution that could handle mud and tomato juice as well as the elements. Its Echuca operation runs 12 harvesters loading tomatoes into more than 300 14-ton capacity bins. Once full, the bins are unloaded at a bin pad where one of 12 trucks picks it up and transports it to a nearby weighbridge.

A single trip from the tomato fields to the Kagome factory takes approximately 90 minutes and each truck can load three bins, with an average of 42 tons of tomatoes per truck. Three years ago, trucks would queue at the weighbridge, waiting for up to 12 minutes before the truck load could be weighed.

This was partially due to Kagome's quality control process, where three samples from each bin had to be processed in the laboratory to check the quality and to validate the tomatoes' origins.

Moreover, paperwork to document the harvesting process and quantity and quality of the yield was required, for which the truck drivers were responsible. A paper-based quality control system of this kind increases the potential for human error, which can result in contaminated products reaching consumers. To ensure traceability, the company wanted a paperless, automated identification solution to be implemented at the weighbridge.

Paperless process

Kagome installed six RFU63x units from SICK at the weighbridge and discharge hill at the factory in Echuca. Each unit was equipped with three antennas for double stacked bins. Resistant and stable RFID tags were attached to the tomato bins, accompanying them from the start of the harvesting process.

The solution helps prevent the typical errors made during inbound and outbound goods processes, such as incorrect quantity and quality data, or missing accounting entries.

RFID also allows real-time identification of where the tomatoes originate. The paperless identification ensures truck drivers no longer need to leave the truck at the weighbridge, contributing to enhanced driver safety.

This efficiency gain translates into the truck spending less time at the weighbridge, removing traffic jams in front of the weighbridge and the tomato drop hill. Truck time at the weighbridge was lowered from 12 minutes to two minutes, enabling truck drivers to do one additional trip per 12-hour shift.

The result was a productivity gain of 504 tons in total, concluded Behrens.