Many times customers come to us and ask for thermal bar code printers. Thermal bar code printers have been around at least since 1991 when one of the largest bar code printer manufacturers was founded, Zebra Technologies. The bar code was first used on a large scale when the Association of American Railroads started implementing a bar code standard across the entire North American railroad fleet. The lines were created with ink and there were issues with smearing, but as the technology advanced, the thermal bar code printer was developed to eliminate this issue.
Well, here we are in 2009 and thermal bar code printing technology has been around quite a while. There is some confusion about what a thermal bar code printer is though. Basically, there are 2 types of printers in this category. There is a Direct Thermal Bar Code Printer and a Thermal Transfer Bar Code Printer.
Lets take a minute to review what this means. Both of these printers are thermal. The difference is how the printer uses the thermal head to make the image. On a direct thermal application, the print head elements are heated and they burn an image directly onto the label itself. A special label is needed for this process because the label must react to the heat generated by the print head.
These labels are called direct thermal labels. Because they react to heat, they are usually used in applications where the label does not have to remain visible for a long period of time. Why is this? Well, the label will fad and if sunlight or a hot environment impacts the label, it will fade, as it reacts to heat. Over time, the image will all be gray or black and not as clear as it once was.
One trick to try when determining if you have a direct thermal label is to hold a match up to the label lit. If the label turns black, it is direct thermal.
So, to sum up the direct thermal printer, it is a printer that heats the label up to make the image and the printer does not use a ribbon. These printers are usually less expensive because they can only do direct thermal imaging and the printer does not have as many parts.
Now when we look at thermal transfer bar code printers, we see a printer that can actually do both direct thermal and thermal transfer printing. These printers are set up with a similar print head, but use a ribbon that is wax, wax/resin, or resin. The print head heats up the ribbon and transfers the material directly onto the label. A thermal transfer label is used and this image will not fade. The durability of the image is dependent on the ribbon used.
The interesting fact about these printers is that the thermal transfer printer can also be used as a direct thermal printer. Just don’t use the ribbon and insert direct thermal labels. There may be a setting you have to make on the printer, but it is that easy. This flexibility comes with a little higher price on the printer, but the labels, or media cost is about the same.
When using direct thermal labels, there is a premium for the labels because the material is more expensive in order for it to react to the heat. When using the less expensive thermal transfer labels, the additional cost of the ribbon makes it a wash.
So this makes the decision on a thermal bar code printer boil down to the customer need. Do you need labels that are permanent, or temporary? Permanent will lead you to the more flexible choice of the thermal transfer option. Temporary leads you to the direct thermal option.