Clothes hanger from Siemens with integrated RFID tag

Laundry washing on an industrial scale is a logistical challenge. Herbert Kannegiesser GmbH from Vlotho is the technology and world market leader in the field of laundry technology. The company has structured its business into the wet area, flat laundry and molded parts divisions and distributed them across several locations worldwide. The specialist for conveyor technology is Kannegiesser Augsburg GmbH, which is driving forward the development of individual solutions for handling and sorting so-called molded parts. RFID technology from Siemens has been a core component of this for years.

As the link between the washing process and dispatch in the customer-specific Transline system solutions, the systems play a key role in determining throughput performance. The manufacturer describes workwear of all kinds as garments. After washing, they must be "ironed" and placed on special hangers for transportation, identified and made known again in the system. RFID technology is a proven means of automatically identifying and tracking the garments and hangers. Special RFID transponders ("tags") are sewn into the clothing and hangers for this purpose. Their hard-coded UIDs (Unique Identification Numbers) are read without contact when the garments are fed in and ironed on and "married" to each other in the control system, which then automatically directs the garments to the correct paths via various reading points.

Tailor-made HF antenna minimizes interference

Kannegiesser and Siemens have jointly modified the existing RFID antenna for the automated and fast identification of garments for the ironing station. One of the new features of the ANT D8 antenna is the antenna loop. This has the effect of canceling out possible interference fields and thus ensures reliable reading. Another advantage is that items of clothing can be detected on both sides of the antenna, which results in a more flexible arrangement of the feeding stations. The large antenna field reliably detects short and long items of clothing.

Multiplexer reduces effort and costs

The use of the RF260X multiplexer, to which up to six antennas can be connected and which is linked to an RF290R reader, significantly reduces costs. Previously, a separate read/write device was required for each antenna, with three to five feed stations being common for medium-sized systems and up to 20 for larger ones. "During development, Siemens took our wishes into account and implemented LED displays on the devices, which makes commissioning and troubleshooting much easier during operation," says Alexander Thoma, Head of Electrical Engineering and RFID Product Manager at Kannegiesser in Augsburg. Without additional devices, it is possible to see whether the device is supplied with power, whether a tag is in the reading range or which antenna is currently being used.

Improved reading speed and reading reliability

Using the Simatic RF260X multiplexer (right), up to six antennas can be connected to a reader - here Simatic RF290R (left) - and scanned sequentially.

The improved Simatic RF382R readers with scan mode functionality are crucial for significantly increasing the conveying capacity and throughput in the subsequent process and when sorting the dried laundry. This automatic read-only mode does not require any special command control, but delivers the transponder data directly to the connected host system. The IP67-rated devices have an integrated special antenna with a laterally aligned field. Compared to the original antennas, this has been more than halved, allowing clothing to hang closer together when reading. This results in an increase in throughput without an increase in speed. The readers are also significantly faster, so that the hangers passing by at a speed of up to 40 meters per minute are reliably read as they pass through - even when the tags are mounted at 90 degrees to the direction of passage. The result is read ratios of at least 10,000 : 1 and therefore very high process reliability. The significantly higher reading speed of 200 to 250 milliseconds expands the possibilities for sorting and buffering before loading. "We still have room for improvement," says Alexander Thoma, "RFID technology would be able to handle speeds up to 50 percent higher."

Transponders withstand heat

One transponder for all tasks - for technical and economic reasons, this is the requirement of logistics specialists. The drying process with temperatures of up to 180 °C over a period of up to 15 minutes and high humidity limits the choice from the outset. The integrated transponders have to withstand these conditions in as many cycles as possible without damage. Kannegiesser uses the ISO15693-compatible Simatic RF200 and RF300 RFID systems with MDS D160 transponders from Siemens. The mobile data storage devices are heat-resistant up to 175 °C. They can even withstand 220 °C for 30 seconds to iron the tags into the laundry.

RFID as a competitive advantage

RFID technology has established itself as a quasi-standard at the Augsburg-based company. "With the technically and economically improved RFID solutions from Siemens, we were able to double the throughput of our conveyor technology to 16,000 parts per hour and further optimize the sorting processes. Siemens has supported us in this and made a decisive contribution to competitive solutions," says Alexander Thoma.

Klaus Müller

Contact:

Herbert Kannegiesser GmbH 32602 Vlotho Tel.: 0 57 33 / 12-0 E-Mail:

Siemens AG 90475 Nuremberg Tel.: 09 11 / 8 95-0 E-Mail: [email protected]www.siemens.de/rfid