How Do Thermal Printers Work?

by Nathan E. Baker; Updated September 26, 2017
Businessman relaxing at his desk

Thermal printers create images using a thermal print head and heat sensitive pigment. These printers employ two different technologies, direct thermal and thermal transfer. They are durable, quiet and easy to set up and use and therefore popular in many business environments. Some FAX machines use thermal print technology.

The Direct Thermal And Thermal Transfer Process

Thermal printers that use the direct thermal process rely on heat-sensitive paper impregnated with pigment that changes color when exposed to the heated print head. Printers that use the thermal transfer process hold a ribbon or cartridge with heat-sensitive pigment, which gets transferred to paper by the heated print head during the print process. Thermal transfer is more common in color thermal printers.

Thermal Printer Disadvantages

Heat sensitive thermal printer paper has a waxy feel to it and should be shielded from heat and light after use, or the printed image may change. Some thermal paper is coated with the chemical bisphenol A. BPA may cause neurological and hormonal disruptions, and can be absorbed through touch. If a thermal printer that uses a ribbon or cartridge gets too warm, too much ink may flow, creating blotchy images. Overheating can damage the thermal print head, and thermal printers can be expensive to repair.

About the Author

Based in Florida, Nathan E. Baker is a professional technical writer and web master. He has nearly three decades of experience with software, surveillance electronics, computers and cyber security. He researches technology and enjoys breaking down complex topics into articles suitable for a wide variety of audiences.

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