Thermal printers, both thermal transfer and direct thermal printers have been available since the late 1970’s, with Sato being the first company to introduce a bar code label printer. Today, other label printing options include impact, laser, and ink jet. However, for the majority of industrial labels which are monochrome, single color labels, and even some pre-printed multi-color labels, thermal printing technology is still the industry standard.
Bar codes which are comprised of lines and spaces are designed to be read quickly and cleanly by the equipment scanning them. Most bar code printers print with tiny dots that are square shaped. These squares have straight edges, which is what bar code scanners like to read. While the majority of thermal printers in operation are standard 203 dots per inch, this rather “low” resolution is just fine for most label printing. While 203 dpi equates to 8 dots per millimeter, 305 dot per inch resolution equates to 12 dots per millimeter. So, for label formats requiring tiny fonts, or curved logos, 305 dpi will provide a more suitable quality. Some printer companies also offer 400 dpi, and more recently 609 dpi print resolution. A few years ago, Sato released their M84 pro printer which at that time was the only printer on the market that allowed for 3 different printhead resolutions. So, if a company purchased 203 dpi printers, they had the ability to swap out 203, 305, and 609 dpi printheads in order to meet new or revised requirements.
Why does thermal printing, both direct thermal and thermal transfer printing, continue to dominate other label printing technologies?
Cost
Prices range as low as $500 for some low-end desktop direct thermal printers. Printhead replacement for these may run $150. Decent industrial printers are priced in the $2000 range.
When we consider the other label printer options such as laser, inkjet, and impact, they are not able to match those benefits listed above. For example, laser-based roll printers are priced in the $10,000 and $20,000 price range, and until their recent revision to LED technology, weren't able to print on polypropylene films due to the heat from the fusers. Laser technology incurs fusers, printheads, drums, and toner. Standard laser printers are inexpensive, but as a rule, sheet fed printers do not have label dispensing and application options; peeling by hand requires a lot of labor. The roll ink-jet printers are priced from $1,500 to the $15,000 range.
Media Options and Cost
The thermal papers and media are still the most cost effective, even when transfer ribbons are included. The thermal transfer printers can run papers, films, and foils when paired with the proper transfer ribbon; no laser or ink jet pre-treatment primer is necessary. Thermal transfer imprinted with resin ribbons is extremely durable. These printer models accept roll form or fan folded stacks of label media. Also important here is the fact that a variety of different adhesives, particularly aggressive ones, can be run through a thermal printer. Most importantly the exact label cost can be determined with thermal printing, whereas the laser and inkjet cost per label are best guess, ballpark estimates.
Ink-jet and laser media typically need to be top-coated with a chemical to be more receptive for the ink/toner, and printing bar codes with ink jet uses a ton of ink—the ultra-high resolution often is not necessary for industrial labels. Yes, laser and inkjet offer ultra-high-resolution printing. But again, for most label print jobs, this is unnecessary. Laser and ink jet also utilize round dots, which is not the best for bar code readers.
Another hidden cost with ink jet printers is the use of ink during a self-cleaning process. Periodically the ink nozzles need to be cleaned and flushed which can use a lot of ink. This cost really adds up for ink jet printers that are not used on a regular basis; the ink dries in the nozzles.
Speed
Some of the newer printer models can print up to 14 inches per second. Even the older ones have plenty of speed at 4 or 8 inches per second. Also, thermal printing offers the fastest throughput—the time required to print the first label.
Ink-jet is now almost as fast as thermal printing, but both laser and inkjet require a much longer throughput time—the time required to queue up and print the first label. Impact printing is still the slowest, but for some applications it is the only choice.
Durability
The majority of industrial model printers will hold up for a decade or more. I have several models in the field, both industrial and desktop, that have been running great for over 10 years. Some have required printhead replacement from normal wear and tear. Thermal printhead pricing averages $150 to $700 depending on width and resolution.
While some laser printer models are quite durable, they do require more maintenance than thermal units. Printheads can cost well over $1,000. If an ink jet or laser printer OEM offers free printheads for the life of the product, I strongly advise finding out in advance what that means. For example, one of the leading ink jet printer OEM's who was touting free replacement printheads during the life of the printer, determined that their $10,000 printers had only a 5-year product life. I have yet to own an ink jet, or laser printer, that ran successfully for over 10 years.
Mobility
This is something I hadn't considered until I had to transport a 100-pound laser printer. Even the most robust, widest thermal printer weighs about half of that, and can be handled by a single human.
Of course, when we start to discuss high resolution color label printing, this starts to get into a different realm. Even so, with thermal printing, labels can be pre-printed with color then imprinted with the variable information later. With the commercial digital presses and quick turnaround times, the pre-printed options have become more viable. Clearly, for most high-volume label jobs, printed in-house, the low cost, fast, old fashioned thermal printers are still the way to go.
Contact RighterTrack today for help in selecting the right label printer model for your business.
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