Product identification and container labeling have become more complex in the past few years. First there was the advent of RFID-enabled labels. Now we're seeing a greater push for mass serialization. And in the next few years there will be a greater emphasis on inclusion of different symbologies such as GS1 DataBar (formerly Reduced Space Symbology / RSS).
Many of you are already doing some form of serialization of shipping container labels, whether it's GS1-128 or some other system. However, there is going to be a greater demand for serialization of sub-packs and inner packs. Some of these may require GS1 DataBar for not only serialization but to include additional types of data. However, there are some tweaks to some versions of the original RSS symbology that have been, or will be, announced. So be sure to check with GS1 on those changes and then with your software/hardware vendor on implementing them.
There is certainly a wide enough choice in printers and labeling systems. At the high end are sophisticated print-and-apply systems for electronic components, shipping containers, pallets, and almost anything else you need to label. On the low end are small portable printers (wearable, integrated and mobile) for point-of-labeling use. And then there's a host of systems in between, including direct marking systems, all offering different capabilities and features. The question in evaluating these options is to look a bit into the future to see what your needs will be in the next 3-5 years.
There are three significant trends in printing that will probably affect you in the future.
One of the more significant trends is the increasing use of mobile printers to bring labeling to the product. Mobile printing is, in some ways, a result of the trend toward a more mobile workforce. Mobile printing provides increased flexibility — whether it's putting a small BlueTooth-enabled printer in a worker's work area for a short period of time, mounting a printer on a lift truck or pallet jack, or providing one to route/field workers. And, while some of the smallest ones are direct thermal, new thermal paper is far more resilient and fade-resistant than you might suspect (although not necessarily intended for permanent marking).
Bringing printing to the product is, in many applications, far more cost- and time-efficient and may eliminate the need for complex conveyor systems. For some 3PL, cross-docking or break-bulk facilities, being able to re-label on-the-fly as pallets are transferred or broken and rebuilt can significantly reduce handling and material handling equipment requirements. For bulky items, mobile printing solutions are preferable to shifting large items to bring them to labeling stations or having workers wander around with streams of labels looking for the right item to affix them to.
Options including wearables, those integrated with mobile computers and WiFi- or BlueTooth-enabled printers on carts or trolleys, are being used to reduce the number of product moves.
During manufacturing, a serial number or lot/batch number may be required and for these applications, direct marking may be the optimal solution. In the past, direct marking was the realm of roller-encoders or industrial ink jet that produced, at best, marginal results. Today, there are relatively high-speed ink jet printers capable of marking items with DataMatrix symbols. Admittedly, the trade-off might be the cost of labels and a dedicated print-and-apply system. Of course, where final product labeling is the goal, rolls of pre-printed labels can be run through a higher quality ink jet printer to add serialized linear or matrix symbols before application.
Laser etch of inked surfaces isn't as popular because of its cost and relatively slower speed. Laser etch and dot peen are still options for hard surfaces where the mark needs to be permanent or survive subsequent processing.
The third significant trend, of course, is RFID labels. Early on, there were problems with conventional bar code printers that had RFID encoders added to them. The problems were less with the printers than they were with the tags (except in cases where roller pressure or flexing of the label cracked the silicon or broke it away from the antenna). Early production runs of RFID labels were notorious for producing “dead” and “quiet” tags. (“Quiet” tags were those where the chip had only marginal contact with the antenna, resulting in seriously reduced read range.) These problems have been resolved.
RFID-enabled tags are much higher quality and more durable. Printers are designed to accommodate the silicon and not induce excessive stress to the RFID component, and are incorporated into virtually every type of printer and labeling system. More features are being added to these systems every day, including what is reported to be the first full-color printer with an RFID-encoder.
There are a lot of options in choosing a printing system and the ultimate decision depends on your needs. However, there is one additional issue that needs to be considered.
Bar code print quality can vary based on duty cycle, symbology, media changeover and label design. Label design, particularly with thermal transfer, should take into account the density of non-bar code items on the label. A label with a heavy horizontal black bar just above the symbol will heat the print head uniformly and there may not be time for it to cool before it has to print the bar code, resulting in excessive bar thickness.
In high volume applications, it's not adequate to verify labels at the beginning, middle and end of each shift. It's important to monitor them during production with a calibrated verifier. And, if there is a noticeable difference between the beginning and end of the shift, corrective action has to be taken before label quality fails. And, as a final note, proper maintenance can help ensure print quality.
Bert Moore is the founder of IDAT Consulting & Education, a technology- and vendor-independent consulting firm that helps clients understand, evaluate and select AIDC technologies and solutions. He is also a member of MH&L's Editorial Advisory Board.
Don't Trust Your Verifier
Print quality programs require a verifier to grade symbols for conformance with standards. But while most people consider maintenance of their printers an essential part of a print quality program, not as many think about recalibrating their verifiers.
For years, GS1 (formerly EAN/UCC) has offered Calibrated Conformance Standard Test Cards (CCSTCs) for linear symbologies (EAN/UCC, Interleaved 2-of-5 and Code 128). These cards have engineered symbols with known quality parameters and flaws. Verifier results are compared to known values and, if there is a variance, the verifier must be recalibrated (usually by the manufacturer).
Until recently, however, there have been no industry-approved CCSTCs for matrix symbols. GS1 US has addressed this by creating not only a new set of CCSTCs for DataMatrix but an entirely new calibration standard in the form of the GS1 US 2D Judge — a precision automated imaging system and software package that grades multiple parameters for each symbol on the card according to international specifications. And even if you're not printing DataMatrix but, say, QR Code, the 2D CCSTC is still valid for verifier calibration.
Both types of CCSTCs are available from GS1 US and selected Certified Solution Partners. However, be aware that CCSTCs have a shelf life and using an old card is like having a fire extinguisher that hasn't been recharged in years. It may give you a warm fuzzy feeling to know it's there, but it's useless when it counts.