As it does on many fronts, Pfizer is taking the lead in implementing RFID (radio frequency identification) for product protection and supply chain oversight. It will be some time before the company has amassed the internal expertise on RFID that it desires, says Tim Marsh, technology manager for Pfizer Global Technology.
Even so, Marsh knows quite a bit more now than even six months ago, when the companys Viagra pilot began. He spoke with Pharmaceutical Manufacturing about the challenges of RFID from a packaging perspective.
P.M.: The impact of packaging on RFID read rates and distances is just now becoming understood. What input/roles have packaging experts had on the Viagra pilot, or on any of your other RFID tests?
T.M.: Various inputs from external sources, RF engineers, packaging people with RF experience and our own internal learning from dealing with RFID contributed to our approach for tagging Viagra. You can certainly read a book about RF, but doing it proves to be the more fruitful approach. Theory is fine for pristine applications, but it can fall short in providing knowledge to make appropriate business decisions. Our experiences in dealing with the Wal-Mart mandate gave us early insight into how readability and read rates are affected by packaging and product and also how to compensate in some cases.
P.M.: Youre using HF tags for the pilot. Was the fact that HF is thought to work better with a wider variety of packaging materials a major consideration in this choice? Did you test UHF extensively at the item level, or make a decision based upon talks with vendors and RFID experts?
T.M.: We selected HF based on several factors. Its an established and mature technology. Its less susceptible to effects from liquids and metals. It is truly constrainable on our packaging equipment, meaning we dont need to erect and install all sorts of shielding and require SOPs for line technicians on where product with tags can be or not be its stupid-proof, to use an old phrase. The frequency is truly global, which is a huge benefit.
Unbiased third parties familiar with installations of LF, HF and UHF gave a resounding thumbs-up for HF at item level once they understood our requirements. Our own experiences with UHF, and its lack of performance and immaturity, meant we would have needed to pay a much higher price to achieve the same results. Combine that with our partners/integrators not being willing to guarantee the UHF solution. Pfizer still does not consider UHF extensible for pharmaceuticals at item level.
P.M.: Have you experienced difficulties in reading RFID tags due to the packaging materials used with Viagra (whether the bottle, safety seal, paper associated with secondary packaging, or other)? If so, what can you share?
T.M.: We are not seeing any unforeseen issues with the HF tags on the bottles. Nothing leaves the packaging line with a dead or inactive tag. We have seen a small number of dead HF tags in the field (at the distributor level) and were working with our partners to understand why this might be happening. We expect the answers to be analogous to what we see for UHF failures for products tagged for Wal-Mart and Target i.e., damaged during shipping.
We have received some complaints about the UHF case tag. This is because of the tags placement on top of the case. Its not the optimal location for full pallet reads, we understand. But it was the only location feasible in the time span of the project.
P.M.: A few experts have suggested that plastics and glasses with certain additives could conceivably interfere with RF signals. Is there anything to suggest this with the Viagra pilot?
T.M.: When you use traditional HF tags that is, tags that are tuned to provide a specific resonating frequency anything you put a tag on will affect its performance. The trick is to determine how much of an effect. If you have additives in the plastic or glass intended to enhance the capability of the packaging, you need to evaluate performance.
Tags on plastics, corrugated, glass and cartons see only small or marginal effects to resonating frequency usually too little to make a real difference. The tag manufacturer can compensate for this if its evaluated in advance. Tags on metal or in close proximity to metal are a completely different story, however.
P.M.: Have other external materials (such as metals on packaging equipment, or warehouse carts or trays) caused interference or compromised the RF signals?
T.M.: Weve not tested to quantify effects from external metals in the RF environment to any great extent. (See answer to question below on optimizing read rates.)
This is a known issue for UHF and is one of the reasons we stayed away from UHF for item level. Our packaging lines are loaded with metals. I would point people to educate themselves about the realities of UHF in practice.
P.M.: Some companies/vendors have experienced increased RF signal strength due to the presence of certain metals in the vicinity. Can you comment on this?
T.M.: Not really. You cant get more power from a reader than what it emits by placing metal in the field that would defy conservation of energy. Placing a metal wave guide, for instance, might channel RF in a manner that allows more of the available power to get to the tags you really want to see. Ive seen wave guides for UHF in use and they work up to a point. Incidentally you dont need a wave guide with HF because its not a propagating wave. With HF you control the shape of the magnetic field with antenna design and power adjustment.