What is thermal printing
There are two methods of thermal printing: direct thermal and thermal transfer. Each method uses a thermal print head that brings heat to the labeled surface. Direct thermal printing uses a chemically machined, heat-sensitive medium that blackens as it passes under the thermal print head, while thermal transfer printing uses heated tape to create durable, durable images on a wide range of materials.
Thermal label printers are ideal for barcode printing because they provide accurate, high-quality images with excellent edge sharpness. Thermal printers are designed to print within tight tolerances and produce exactly the bar widths required for successful barcode printing and scanning. Each technology allows you to create one- and two-dimensional barcode symbols, graphics and text at the same resolution and print speed.
Direct thermal printing
Because they print without tape, thermal printers for direct printing stand out for their simplicity. Direct thermal print labels tend to have a long shelf life, but are not well suited to environments where they are exposed to heat, long periods of direct sunlight or abrasion. Thermal printers have no ink, toner, or tape.
If the label is overexposed to heat, light or other catalysts, the material darkens and makes it impossible to read the text or barcode. For these reasons, direct thermal printing is not used for lifetime identification applications. The readability of direct thermal labels, wristbands , and receipts varies greatly depending on the conditions of use, but this technology provides sufficient durability for many popular barcode printing applications, including shipping labels, patient and guest identification, receipts, and ticket printing.
Advantages of direct thermal printing
- Direct thermal printing ensures sharp print quality and good scanning.
- Thermal printing is ideal for applications that require only a short shelf life. Ideal applications are, for example, shipping labels and receipts, as opposed to product labels.
- Thermal printers are simple to use compared to most other printing technologies because they don't require monitoring or refilling of ink, toner, or tape.
- The lack of consumables to replace outside of the material to be printed means that long-term maintenance costs remain low.
- Direct thermal printing allows you to print batches or individual labels with virtually no waste.
- With the availability of recyclable materials, direct thermal printers save the environment.
- Thermal printers are usually more durable to build than dot matrix or laser printers, allowing them to work reliably in industrial and office applications .
Disadvantages of thermal printing
- Direct thermal printing is extremely sensitive to environmental conditions such as heat and light (fluorescent and/or direct sunlight).
- Direct thermal paper remains chemically active when printed. For this reason, thermal labels, tags or ticket stocks are often coated from above to be resistant to UV radiation, chemicals and abrasion.
Thermal transfer printing
Labels with thermal transfer printing can be easily recognized by the expressive, often glossy, printed surface. Transparency is achieved by using a thin roll of tape, which, when heated by the print head, melts on the label to form an image. The ink is absorbed so that the image becomes part of the media. In combination with the right carrier, thermal transfer technology is not only resistant to heat and moisture, but also cannot wipe off the image, making the printed labels the most durable available. An additional advantage of this technology is the continuity of the printed image. Because the color and density of the printed image depends on the tape and resolution of the printer, thermal transfer printing provides consistent, reliable printing on each label. This technique provides image quality and durability unmatched by other on-demand printing technologies.
The specified label material and tape must be precisely matched to ensure the performance and durability of printing. By choosing the right combination of carrier-ribbon, as well as special adhesives, users can create labels of archival quality, resistant to temperature extremes, ultraviolet radiation, chemicals, sterilization and more. Typical thermal transfer applications include: product identification, CIRCUIT BOARD tracking, permanent identification, sample and file tracking, asset tagging, inventory identification, certification labels such as UL/CS, laboratory samples, cold stores and freezers, and outdoor applications.
Advantages of thermal transfer printing
- Thermal transfer printing provides crisp, high-resolution text, graphics, and barcode printing for maximum readability and scanning.
- Thermal transfer printing ensures long-term image stability.
- Thermal transfer allows you to print batches or individual labels with virtually no waste.
- Long-term maintenance costs are low compared to dot matrix, inkjet and laser printing.
- Thermal transfer technology allows you to print on an almost unlimited range of media (except multi-format).
- Thermal transfer printers are typically built more durable than dot matrix or laser printers, allowing them to work reliably in industrial and office applications
Disadvantages of thermal transfer printing
- Because thermal transfer printers require tape, delivery costs are higher than direct thermal printing; however, thermal transfer heads last longer than thermal heads.
- A single-pass thermal transfer tape can be a waste if few are printed on it.
- Thermal transfer tape is a poor candidate for recycling.
- For optimal print quality in thermal transfer printing, the tape and substrate MUST be compatible. Otherwise, the heat from the print head may melt the tape on the label, causing internal problems with the printer.