Korean tire manufacturer Kumho Tire is employing passive ultrahigh-frequency (UHF) RFID tags to track its consumption of the rubber materials that it uses to assemble tires at two of its factories. Qbit‘s RFID solution is enabling the company to boost its efficiency, better manage its rubber material and ensure that the rubber is used on a first-in, first-out (FIFO) basis, thereby allowing it to consume the material before it stiffens with age or reaches its expiration date. The system has been installed at Kumho’s plants in the South Korean cities of Gwangju and Gokseung, while several of its other factories may take the system live during the next two years.
The company reports that it has already gained a return on its investment by increasing efficiency and eliminating the need to discard unused rubber due to it having expired before the material could be incorporated into a tire.
Kumho Tire, owned by conglomerate Kumho Group, manufactures a wide range of tires under the Kumho and Marshal brands at its facilities in South Korea, as well as in China and Vietnam. The company claims that it is the ninth largest tire manufacturer in the world, and one of the largest in Korea.
In 2013, Kumho Tire’s factories in Gwangju and Gokseung began applying passive UHF RFID tags to bus and truck tires (see Tire Manufacturers Roll Forward With RFID). The tags were designed for use in inventory management and logistics at distribution centers.
At that time, the company also wanted to track those factories’ rubber material inventory levels and work-in-progress. To do so, it required a real-time location system (RTLS) that could cover each plant’s approximately 200,000-square-meter assembly floor. The company wanted to use the low-cost passive UHF RFID tags, however, rather than battery-powered RFID tags that can be more expensive but provide RTLS data.
According to a Kumho Tire spokesperson who asked to remain anonymous, the company went about seeking a passive system that would still provide some level of real-time location of tagged items. “There is no other choice for RTLS [involving] passive RFID,” he says, referring to Mojix‘s STAR RFID technology provided by Qbit.
The new system was taken live early this year.
Rubber used in tire manufacturing has a limited shelf life—if it isn’t used by a specific date after its creation, the material begins to deteriorate. That means that every sheet of rubber at the two tire plants has a short useable period before reaching its expiration date. “After the valid date passes, the rubber has to be discarded,” the Kumho Tire spokesperson explains. What’s more, raw rubber molds into tires best when it is first created and is thus soft and pliable. Therefore, the company wanted to consume rubber sheets on a FIFO basis. “That prevents waste of material and makes a better-quality tire,” says ChongWoo Kim, Qbit’s CEO.
The process of selecting the best RFID solution took several years, Kim says. Asiana IDT, a partner company within the Kumho Group, came across the Mojix solution from Qbit at an RFID convention. It then spent the next several years determining the best way in which to apply this technology to the company’s existing operations.
Next, Kumho Tire and Qbit piloted the solution at a single factory, by tracking pallets loaded with rubber and determining whether those batches of material could be located throughout the facility. UHF RFID tags, supplied by Korean company Exax Inc., were attached to slips of paper placed on the stacks of rubber. The pilot found that the receivers captured tag location data well throughout the facility.
This year, each factory installed 18 STAR receivers and more than 2,000 Mojix reader antennas. With the full solution in place, an RFID-tagged slip of paper is inserted in each stack of rubber, using RFID labels printed and encoded onsite via a Bitek Technology printer. In addition, an RFID tag is attached to every cart used to transport partially manufactured tires.
Qbit software, residing on Kumho Tire’s database, stores information linked to the RFID tags. When rubber sheets are placed in a stack, each sheet’s tag ID is stored in the Qbit software, along with the rubber’s manufacturing and expiration dates. Mojix eNodes power up the tag when it comes within range, and the tag, in turn, transmits its ID. The tag’s signal is picked up by the antennas wired to the receiver, which then forward that data to the software, thereby indicating the rubber’s location in real time.
As the sheets of rubber are moved out of the staging area and into the manufacturing area, the pile’s tag is read and the software thus calculates its location. The company then knows when its rubber supply needs to be replenished, and if a stack of rubber sheets is being transported to the assembly area ahead of one created prior to that stack. In that case, an alert can be displayed in the software and an assembly manager can correct the mistake before the sheets are actually used to build a tire.
As the tires are partially assembled, they are placed on RFID-tagged carts and transported to the next work area. As the carts move to each location, the Mojix system interrogates their tags, thereby updating the software to indicate how many tires have reached that stage of the assembly process and, thus, how much more rubber material will soon be required.
Since the system’s installation, Kumho Tires has reduced its expenses by not having to discard rubber due to it having expired. The firm has also improved the quality of its end products, by ensuring that rubber is used as quickly as possible, when it is at its softest and most pliable.
The company has decided to install RFID at some of its other plants, Kumho Tire’s spokesperson says, or is currently in discussions to do so. “We are planning for the deployment at the factory in China in 2016,” the spokesperson states.