RFID Printers Encoders are used in applications where wet inlays or label are used to tag inventory or assets. The printers encoders not only print on the top of the label but also encode information into the RFID chip.
RFID printers in an automated RFID system often utilize existing print points within a manufacturing or distribution supply chain. Because many of the current Auto-ID systems use barcoding, the conversion to RFID systems will be an incremental change. The first step in enabling your current barcode printing and application points with RFID will be to obtain RFID-enabled label printers.
How do you select the right printer encoder?
There are several criteria:
Print volume and speed – There are many printers encoders on the market and they differ by how fast they can print and encode a label and also for how high volumes they are suitable. Industrial printers will have higher speeds and will last longer thus printing more labels in the long run, which may not be accomplished by simple desktop or portable printers.
Print resolution – Print resolution will be important in situation when printing on the label is more complex and requires higher resolution, for instance when printing logos or graphics. Printers range around 200 – 600 dpi but you can find printers with lower or higher resolution as well. 200 dpi is plenty for regular printing needs like text or barcodes.
Print method – There are two types of print methods.
o Thermal transfer, which uses heat to transfer ink from a separate ribbon to the label. For long-term application where the labels will have a lengthy lifecycle in the supply chain, thermal transfer printers should be used as the labels do not fade with exposure to sun or heat. These printers will typically print with a higher DPI (dot per inch), or resolution, on the label.
o Direct thermal, which uses special media in the form of a treated label stock that turns black when heated. The advantages of a direct thermal printer are a simpler design and therefore easier loading of the media, no ribbon, and easier maintenance for the printer due to fewer components that could break. However, the labels tend to be more expensive and fade quicker when exposed to heat.
Network connections – How will you connect your printer to the network? Most printers provide USB or Ethernet connection, however, you can also find Parallel, Wi-Fi or Bluetooth connectivity.
Space – How much space do you have for your printer? Some of the units are quite large, usually the industrial printers, however, simple desktop printers can be half or third of the size. Portable printers will be the smallest and they can be often fastened to a pocket or a belt.
To use an RFID-enabled label printer, you must first perform a case analysis to determine what tags and labels are correct for use with your application.
The case analysis will include a detailed assessment of the contents of the package and its effect on RF, the package material and its effect on RF, the package surface characteristics for selection of the proper adhesive, the packaging design, and the method of attachment to be used for tagging the cases and products. Large part of the tag/label selection will be dependent on what you are tagging and the environment and for more information about that, visit Criteria for Selecting the Right RFID Tag.
Size and adhesive
The label should be large enough to display all of the existing printed information as well as any additional information required for the RFID tag embedded in the back of the label, such as the EPC logo to indicate the use of an EPC tag within the label.
The size should also be appropriate for the boxes to which the labels are applied. You must also consider the compatibility of the label adhesive with the boxes, the method of attachment, the environment in which the tagged assets will be moving, as well as the requirements of the label applicator.
Quality is of prime importance when selecting label stock. This media has to deliver consistent and reliable results. If quality varies dramatically from one roll of media to the next—or, even worse, from one tag to the next—it will make the entire system inefficient. Sufficient time and attention to detail in selecting the proper media is critical to the overall success of any RFID implementation.
Inlay Position within the Label
The RFID tag must be positioned so it aligns correctly with the encoder antenna so that it can be read or written to. This positioning changes from one printer to the next, as many printers have their antennas placed at different locations within the print pad. Each label will be specific to a particular type of printer for which it is designed and the inlay position in the label should match the specifications provided by the printer manufacturer. If the inlay position does not match the required specifications, you will not be able to use a default mode and you will need to run a calibration process to make sure the printer determines the inlay’s position. You can see various tag alignments in the smart label below.
You can encounter a quiet tag. This happens, when a tag inside a label fails to operate within the specifications. Quiet tags can be a major concern for label makers as well as users.
Most RFID-enabled label printers have a way of verifying the function of the tag in the label and assessing its readiness for use. These printers will determine the response of the tag, and if the tag does not fall within the manufacturer’s suggesting quality guidelines, the tag will be rejected and a special pattern will be printed on the front of the label, indicating it should not be used. The printer will then generate the next available label on the print line.
ESD and Tag Handling
The tag within a smart label contains delicate electronic components and must be handled just as you would handle computer components. Take care to avoid subjecting tags to electrostatic discharge (ESD), crushing, dropping, and exposing to moisture and extreme temperatures. You must consider all of these aspects when choosing proper storage locations and handling procedures before you purchase and use a smart label.
Tip: Most RFID-enabled printers have validation and error recovery built in, and the command structure to control the printer is similar to existing barcode printers, with the addition of RFID control commands to enable the encoding and verification of smart labels.
With thermal transfer printing, you will also need a ribbon. The ribbon can be coated with wax, combination of wax and resin, or just resin. Wax ribbons are cheaper and are great for printing on coated paper, while resin ribbons are more expensive but they are more suitable for printing on gloss paper or glossy synthetics, they are also more scratch resistant.
Resin print is also more resistant to harsh or extreme chemicals as opposed to wax print, that is resistant only to weak chemicals (like window cleaner). The combination of wax and resin is suitable for coated paper and matte synthetics, provides moderate scratch resistance and withstands moderate chemicals.
Ribbon also come in different widths, which will affect, how wide you can print. You should match your ribbon width with your label width.
For more information on Tag Types, review: