Direct Thermal Vs Thermal Transfer

Direct Thermal Printing

Utilizes heat-sensitive media that blackens as it passes under the printhead. Because they print without a ribbon, direct thermal printers are noted for their simplicity. Direct thermal printed labels typically have a considerable shelf life but are not well suited for environments that expose them to long periods of direct sunlight, heat or abrasion.

Advantages

  • -Sharp print quality with good scannability.
  • -Ideal for applications requiring only a short shelf life. Shipping labels and receipts are ideal applications while product labels are not.
  • -Easy to operate because there is no ink, toner or ribbon to replenish.
  • -Low long-term maintenance costs since there are no supplies to replenish other than the printing material.
  • -Direct thermal enables batch or single label printing with almost no waste.
  • -Environmentally friendly due to availability of recyclable materials. 
  • -More durable build than dot matrix or laser printers, allowing reliable operation in industrial as well as office applications.

 

Limitations

  • -Sensitive to environmental conditions such as heat and light (fluorescent and / or direct sunlight).
  • -Direct thermal paper remains chemically active after printing. Because of this, thermal labels, tags or ticket stock are often top coated to resist UV light exposure, chemicals and abrasion.

Thermal Transfer Printing

Thermal Transfer technique produces crisp, superior image quality and durability that is unmatched by other on-demand printing technologies. This is achieved by using a thin ribbon roll that when heated by the printhead melts onto the label to form the image. The ink is absorbed so that the image becomes part of the media. When matched with suitable media, the image is resistant to heat and moisture and cannot be rubbed off, making the printed labels the most durable available. An additional benefit of this technology is the continuity of the printed image. Because the color and density of the printed image is determined by the ribbon and the resolution of the printer, thermal transfer printing produces consistent, reliable printing.

By selecting the right media-ribbon combination, as well as specialty adhesives, thermal transfer labels can withstand temperature extremes, ultraviolet exposure, chemicals, sterilization etc. 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/CSA; laboratory specimens; cold storage and freezers; and outdoor applications.

Advantages

  • -Produces high-definition text, graphic and barcode print quality for maximum readability and scannability.
  • -Produces long-life image stability.
  • -Enables batch or single label printing with virtually no waste.
  • -Low long-term maintenance costs as compared to dot matrix, ink jet and laser printing.
  • -Can print on a nearly unlimited variety of media stock (except multi-form).
  • -More durable build than dot matrix or laser printers, allowing reliable operation in industrial as well as office applications

Limitations

  • -Supply costs are higher than direct thermal due to use of ribbons. However, thermal transfer printheads last longer than direct thermal printheads.
  • -Single-pass thermal transfer ribbon can be wasteful if little is printed on it.
  • -Thermal transfer ribbon is a poor candidate for recycling.
  • -To obtain optimum print quality in thermal transfer printing, the ribbon and media substrate MUST be compatible. Otherwise, the heat from the printhead could melt the ribbon onto the label causing internal printer problems.

 

Source: Adapted from www.zebra.com