RFID printers are used to replace manual coding and add visible characters to RFID tags. These devices are basically an RFID reader and a printer combined into one machine. UHF, HF and NFC tags can be coded by an RFID printer as long as the RFID tag is compatible with the given printer. It is important to check that the label size is compatible with the printer’s specifications. Currently, RFID printers can code and print paper and foil labels as well as special labels on metal (all RFID tags in industrial enclosures have to be manually coded). The RFID reader inside the printer serves as both an encoder and a verifier for all tags that pass through the unit during reading. It encodes tags with new information, and then reads the tags before releasing them to see if the tag contains valid, new information. RFID printers print on average about 20 labels per minute depending on the set printing speed and label size. Because RFID printers are fast and accurate, they are essential in applications where a large number of RFID tags are required.
In most RFID printers, two printing methods are available: direct thermal printing and thermal transfer printing.
Direct thermal printing is only possible on a specific type of paper that darkens when it touches the hot print head. This type of printing is less frequently used because it is sensitive to sunlight and high temperature, which causes the printing to disappear after some time. The advantage is print speed, quiet operation and lower cost.
Thermal transfer printing is carried out by using a special dye tape, its coating is warmed up by the print head, as a result of which the dye from the tape is adhered to the material that is being printed. This method is used more often because of the durability of the print.
The cost of an RFID printer is relatively high. Before buying a printer for RFID tags, it is worth considering:
- the amount of time spent manually tagging / coding costs by an external company – the cost of manual coding along with the cost of errors per year may be close to the cost of purchasing an RFID printer,
- RFID printer capabilities – it can quickly code tags, and print a readable number, logo or bar code on the front of the tag. In addition, it is much more accurate than manual tagging, which is fraught with the risk of human error.