The Evolution of RFID in Metalworking

RFID – A key technology in modern production

It’s not just IIoT that has focused attention on RFID as a central component of automation. As a key technology, radio frequency identification has been long established in production. The inductive operating principle guarantees ruggedness and resistance to environmental stress factors. This makes the system highly reliable in function and operation. With unlimited read/write cycles and real-time communication, RFID has become indispensable. The beginnings for the industrial use of RFID go far back. RFID was first successfully used on machine tools in the mid-1980’s. Since the usage of RFID tags on cutting tool holders has been internationally standardized (ISO 7388 for SK shanks, ISO12164 for HSK shanks), there has been strong growth of RFID usage in cutting tool management.

Cutting tool in tool taper with RFID chip

Track-and-trace of workpieces

Modern manufacturing with a wide bandwidth of batch sizes and ever compressed production times demands maximum transparency. This is the only way to meet the high requirements for flexibility and quality, and to minimize costs. Not only do the tools need to be optimally managed, but also the finished parts and materials used must be unambiguously recognized and assigned.

Workpiece tracking with RFID on pallet system

RFID frequencies LF and HF – both RFID worlds come together

In terms of data transmission for cutting tool identification, established systems have settled on LF (Low Frequency), as this band has proven to be especially robust and reliable in metal surroundings. Data is read with LF at a frequency of 455 kHz and written at 70 kHz.

When it comes to intralogistics and tracking of workpieces, HF (High Frequency) has become the standard in recent years. This is because HF systems with a working frequency of 13.56 MHz offer greater traverse speeds and a more generous read/write distance.

As a result, RFID processor units have been introduced that offer frequency-independent application. By using two different read-/write heads (one for tool identification and one for track-and-trace of workpieces) that each interface to a single processor unit, the communication to the control system is achieved in an economical manner.

RFID processor for both tool identification and workpiece tracking

New Hybrid Read-Write Head

Industrial equipment is designed for a working life of 20 years or even more. Therefore, in production you often find machines which were designed in the last century next to new machines that were installed when the production capacity was enlarged. In such a brown field factory you have the coexistence of proven technology and modern innovative equipment. For the topic of industrial RFID, it means that both low frequency and high frequency RFID tags are used. To use both the existing infrastructure and to introduce modern and innovative equipment, RFID read/write heads have been recently developed with LF and HF technology in one housing. It does not matter whether a LF RFID tag or a HF RFID tag approaches the RFID head. The system will automatically detect whether the tag uses LF or HF technology and will start to communicate in the right frequency.

This hybrid read-write head adds flexibility to the machine tools and tool setters as you can use the entire inventory of your cutting tools and tool holders.

RFID Tool ID tag ready for the Cloud

The classical concept of data storage in Tool ID is a decentralized data storage, which means that all relevant data (tool dimensions, tool usage time, machining data, etc.) of a tool/tool holder is stored on the RFID tag which is mounted on the single tool holder. The reliability and availability of this concept data has been proven for more than 25 years now.

With the Internet of Things IIOT, the concept of cloud computing is trendy. All — tool setter, machine tool and tool stock systems — are connected to the cloud and exchange data. In this case only an identifier is needed to move and receive the data to and from the cloud. For this type of data management Tool ID tags with the standard (DIN 69873) size diameter 10 x 4,5 mm are available now in a cost effective version with a 32 Byte memory.

Evergreen – more modern than ever: RFID Tool ID in Metalworking

Learn more about the Evolution of RFID in Metalworking from true experts at www.balluff.com  or at  Balluff events worldwide

Optimized Utilization and Increased Transparency with RFID

Unscheduled downtimes in production due to worn out or unserviced molds in machines can cause high costs and are a well-known problem for a lot of companies. In order to prevent these issues and optimize the use of their injection molds, a Swiss chocolate mold producer installed a predictive maintenance system via industrial RFID technology.

Maintaining oversight during frequent mold changes with RFID

Complex and expensive injection molds are typically used in manufacturing parts. Due to wear and contamination, they require regular cleaning, care and maintenance. The regularity often depends on handwritten records in a molds log-book, post-its or on the experience of the employees. In more modern companies, databases or excel sheets may be used to store this information. Regardless of the method, real-world experience shows that manual recording is often prone to errors. Maintenance and inspection are often only carried out if a mold malfunctions, when it tends to be too late.

Poured chocolate molds endure wear and need regular maintenance

Poured chocolate molds, that are used in continuous operation on the production lines of chocolate manufacturers, are known worldwide for their perfection and durability. In most cases, they are made in comparatively small batch sizes of 1500 to 2000 units. For this reason, the injection molds have a modular structure. The base is a master mold with exchangeable inserts which leads to quick and frequent mold change cycles. Additionally, there are certain things that require increased maintenance, like replacing hoses, lines or connecting components, that involve removing the master mold. This is why it is especially important to keep track of how many times a master mold has been used. A control system via industrial RFID technology can be installed to solve this problem.

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Increase Competitiveness with RFID in the Intralogistics Industry

In times of globalization and high labor costs it is a challenge to increase competitiveness in the fashion industry. Within a warehouse, an RFID system supports a high degree of automation as well as short transport distances. To supply dealers and to keep their facility profitable, one of the most successful fashion companies in the world has built a highly modern hanging garment distribution center. Let’s take a look at how they successfully implemented RFID technology to improve their processes.

Separate and sort clothes with just one hybrid module (2D code + RFID)

Within this distribution center 45,000 of these innovative clothes hanger adapters (L-VIS) are used. They replace the previous trolley-based logistics approach by allowing the transportation of a number of different garments that have the same destination.

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L-VIS, clothes hanging adapter made by P.E.P. Fördertechnik

With the investment in some additional space in the so-called buffer or storage zone, and by providing empty trolleys at various locations to keep the product flow moving, this project is successfully accomplished. A major advantage of this system, is the usability over the entire intralogistics chain. From receiving, to the hanging storage, to the sorter for single item identification, and from there as a transport unit to shipping.

The clothes hanger contains an RFID chip, that is automatically read by the conveying technology, and the 2D-code. This code is read manually by employees with a portable acquisition unit. The code can be DMC (Data Matrix Code), QR-Code, or any other optical code standard.

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HUGO BOSS garment distribution center (Metzingen, Germany)

Information exchange without visual contact

A high frequency RFID chip is installed. With this identification system, neither direct alignment nor contact is needed to enable data exchange via nearfield communication. Non-contact identification is extremely reliable and wear-free. The identification system consists of a rugged data carrier, a read/write head and an RFID processor unit. The processor unit communicates to the control system via Profibus, but could be accomplished with ProfiNet or EtherNet/IP as well.

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BIS-M RFID processor unit

The following table gives you an overview of types of Radio Frequency Identification solutions that are available on the market:

Common Types Low Frequency Low Frequency High Frequency Ultra High Frequency
Frequency 70/455 kHz 125 kHz 13.56 MHz 860 … 960 MHz
Short description Dedicated solution to tool identification in Metal-Working industry. Standard solutions for simple Track & Trace applications. Fast & reliable – even with high volumes of data in medium distances in assembly, production and intralogistics. Identification at large distances and bunching capability for current material flow concept.

For the customer, the decision to choose this particular system among others was the separation between the processor and read/write head. In a widespread facility it would not make sense to have a decoder with 30 read/write heads attached. By interfacing two read/write heads per processor, it is possible to track the travel of a transport unit over the entire conveyor line as well as track within the aisles between the individual shelves.

An additional advantage of the system implemented is the housing options. The L-VIS carrier and the 30 mm read/write head are an ideal match. The simple mounting of the processors and ready-to-use connection were of high value to the system integrators. In the sorting area, a 2D code was supplemented by the RFID tags to reach speeds of up to 0.6 and 0.7 m/s. This would probably not have been possible with the installation of a corresponding camera technology.

Experiences have shown, that RFID projects need a lot of support. Consultation and assistance from true experts can be provided by our team. Learn more about RFID technology here.