Aug 30, 2007This article was originally published by RFID Update.
August 30, 2007—RFID performance is governed by physics, but finding the right solution is sometimes more art than science. That's the lesson integration firm Barcoding Inc. learned during a project to identify specialty metal pipes. Tags specifically designed for use on and around metal didn't provide acceptable performance, yet flexible adhesive tags created for garment tracking did. As a result, a U.S. specialty pipe producer (that wishes to remain anonymous) uses RFID instead of manual methods to track inventory and verify loads.
"Prior to finding this tag, we were close to giving up," Bill Paulsen of Barcoding told RFID Update. "We tried about two dozen different tags, and there were certainly times we thought it just wasn't going to work out."
The pipes, which are about 20 feet long and range from approximately six to 24 inches in diameter, have too much metal for most UHF RFID systems to handle. The customer's processes required more range than HF technology could deliver. Bar codes weren't suitable since the symbol is often inaccessible to the reader due to how the pipes are stacked and stored.
Finished pipes look similar but often differ by the alloy used and may have slight differences in diameter, so accurately identifying them to meet customer specifications can be a challenge. Furthermore, they may be stacked 20 feet high and are stored in a warehouse or outside in a yard. Pipes were previously identified by writing ID numbers on them with a permanent marker, which made it difficult for workers to quickly locate and identify pipes to fill orders.
Some metal-mount UHF Gen2 tags had acceptable reading performance, but couldn't be used because the mountings might scratch the pipes. Barcoding spent two to three months testing various tags and mounting options.
"Trying all the different tags was a chore, not so much to get good reads, but to find a place were we could put the tag without it being destroyed," said Paulsen.
Barcoding solved the problem by using a flexible garment tag that is produced on a smart label printer/encoder. The design resembles a flag on a pole and includes an adhesive strip that folds down and adheres to itself. The tag is attached to the lip of the pipe so the flag hangs below, where there is enough air around it to avoid excessive interference.
The pre-encoded tags are provided by RFID TagSource. They are run through a printer/encoder from Zebra Technologies, which generates an EPC number and prints text on the label.
Pipes are identified by RFID when they are placed into finished goods inventory, whenever they are moved into or out of storage, and when they are picked to fill customer orders. The company's legacy warehouse management system directs these activities, and Barcoding developed an interface to integrate the RFID data.
"It is very important that workers get the proper pipe that's made from the right material," said Paulsen. "Using RFID to verify what is picked is a very important part of this application."
Pipes are moved with forklifts that have special adapters that fit inside the pipe to lift them. The forklifts were already equipped with mobile computers, and were retrofit with mobile-mount RD500 RFID readers from Motorola. Some Motorola handheld readers are also used to identify pipes in different processes, and fixed-position readers are being considered.
The system has been running for about two weeks and has provided acceptable read rates and performance. It was in place approximately six months after Barcoding first spoke with the company. The company is not disclosing results such as time savings or error reductions, but may come forward in the future.
"There were plenty of times we thought about scrapping the idea, but the customer wanted to keep trying and kept pushing," said Paulsen. "They had a vision of how RFID could help them, and now they've improved their processes as a result."
This system is notable for several reasons besides the creativity required to get it to work. It illustrates how Gen2 technology is continuing to penetrate areas that were not traditionally served by UHF technology (see Kids Clothes Firm Outgrows HF, Puts on Gen2 RFID and TAGSYS Announces Two Apparel RFID Deployments for two other recent examples). The pipe tracking system also shows that although Gen2 technology is standardized, it is not a commodity and multiple form factors with different performance characteristics are needed. Finally, the application is yet another example of the value achieved from closed-loop systems, where RFID has gained strong traction even while supply chain adoption trails earlier projections.
