New RFID Shield Installs Like Wallpaper

Retailers can apply Avery Dennison's ShieldSense RFID Blocking Material to walls, barriers or other surfaces where stray RFID reads could occur, simply by peeling off the back and rolling it out.
Published: April 29, 2019

Several large retailers have deployed a new RF shielding solution from Avery Dennison that can be applied to walls, doors and barriers like wallpaper, thereby isolating RFID tag reads to specific areas. With the product, known as ShieldSense RFID Blocking Material, companies can identify whether tagged goods are in a store’s front area or back room, or in a specific fitting room, as well as combat shrinkage, by identifying where tags were last detected. The product is designed for UHF RFID transmissions, but can also isolate HF and NFC transmissions.

Avery Dennison designed the RFID Blocking Material as an affordable solution to prevent stray RFID tag reads, one that can be easily installed without requiring staples or other attachments, says Chris Blackwell, Avery Dennison’s product manager of electronics and printing and packaging. The technology is already in use at more than 1,000 stores throughout the United States and Europe, while Avery Dennison is currently in discussions with other retailers, as well as companies in other sectors, such as aerospace and automotive.

The first deployments in retail are aimed at reducing shrinkage and improving inventory accuracy. “A lot of retailers are trying to gain greater control over inventory,” Blackwell explains, beyond a basic count of units on the store premises. In fact, he says, retailers using RFID often want a better sense not only of where inventory is located, but also where it isn’t.

Stores utilizing RFID technology for inventory management employ either overhead readers that capture all tags within a specified area or zone, or handheld readers operated by sales personnel to conduct periodic inventory counts. In either case, Blackwell says, the isolation of reads to a particular area can be challenging. For instance, goods may be stacked against both sides of a wall separating the stock room from the store front. Thus, if a sales associate were attempting to read tags on the sales floor only, he or she might inadvertently capture reads from the products on the other side of the wall, in the stock room.

Such errors can mean that replenishment would not occur when it should, and that merchandise would not be available for customers even if the RFID data seemed to indicate it was. Stray reads are a problem not just in retail, though—manufacturers, logistics providers and companies in other sectors have been challenged with preventing the reading of tags that should not be interrogated but are located within range of a reader.

To resolve this problem, some companies in the past have relied on software to identify and filter out stray reads. However, Blackwell notes, that can be expensive. “If you’re on a budget,” he states, “that wouldn’t be your best choice.” Others have created their own shielding with aluminum sheets that they purchase and mount, but the shortcoming there is the installation costs. Since the sheets are not designed for that specific use case, they may need to be cut, the reader infrastructure may need to be removed prior to their installation, and fasteners or screws might be necessary, which could create a hole through which RF signals could still leak.

Avery Dennison was well poised to offer an easier alternative, Blackwell says, since it specializes in RFID and makes the materials necessary for shielding, as well as for adhering that shielding to reader portals, walls or barriers. ShieldSense is a 2- or 5-mil-thick (a mil is a measurement that equals 0.001 inch, or 0.0254 millimeter) aluminum foil that is available in 30-yard rolls. The width is available at between 4 and 54 inches, and the roll size can be modified to accommodate an end user’s installation requirements—for instance, ensuring rolls aren’t too heavy for installers to safely left them to certain heights.

The sheets come with an adhesive. Installers can peel off the liner and apply the sheet to a wall or other surface, then press it to create adhesion. The adhesive is designed to set only after an hour or so, so users can pull the sheet back up and readjust it during installation without damaging the sheet or the surface to which it’s applied. “You don’t need extra staples or fasteners,” Blackwell says. Avery Dennison works with installers, such as BEC Group, enable fast installation for chain retailers and other businesses.

Once the ShieldSense material is installed—for example, in a wall between a stock room and a store front—sales associates can ensure that tag reads are captured only in the areas of interest, without requiring special training. A worker can simply go into the stock room, Blackwell says, then close the door and isolate the units to be read. He or she can also carry a handheld reader onto the store sales floor and accomplish the same thing.

While retailers are adopting the technology first, Blackwell says, the company is working with multiple businesses that have expressed concerns regarding stray reads. The ShieldSense technology blocks not only UHF RFID transmissions, but also 13.56 MHz HF or NFC signals (complying with the ISO 15693 or 14443 standards). The 13.56 MHz applications that would benefit from ShieldSense, according to the company, include installations in which items are stored in small compartments in close vicinity with similar compartments, such as bins of food or assembly components. The shields may also be able to block radiation.

Avery Dennison tested several versions of the new material at its RFID Lab in Miamisburg, Ohio, including 2-millimeter and 5-millimeter tape, both of which provided attenuating at approximately 98 percent of UHF RFID signals. The new shielding, Blackwell says, has been beta-tested by half a dozen retailers at 1,000 sites.

One impact the product will have for its customers, Blackwell predicts, is bringing greater inventory control to retailers. In the case of shrinkage or theft, for instance, companies often lack a clear understanding of when and where products go missing. With awareness of where inventory was last seen, such as in the stock room, a company can know where loss is occurring and thus address the problem—for instance, by installing cameras or retraining personnel.

Shrinkage, in fact, poses a significant expense for retailers. According to a National Retail Federation security survey, 2 percent of sales are lost to shrinkage, which in 2016 equated to $49 billion lost worldwide. For inventory accuracy, the assurance that a product is at a specific location not only prevents out-of-stocks, but also enables analytics. For example, if a product in a store front hasn’t been selling, while a large number of the same product is detected in the stock room, a retailer could reduce that item’s price to foster greater sales.