Thermal Transfers Uses and Definition

Thermal transfers are best known for the printing of high quality designs and identification labels and are used for printing designs and high quality bar codes This article will describe how thermal transfers operate and provide some basic tips about the use of thermal printing.

With respect to printing, a thermal transfer is implemented when a specialized printer melts wax within its print-heads and uses it to print a design or text onto paper. Thermal transfers are usually preferred over direct thermal printing on surfaces that are heat sensitive or when higher durability of printed material (especially against heat) is desired.

Thermal Transfer is a popular printing process particularly used for the printing of designs or identification labels. Thermal transfers are an extremely popular printing process in the industrially developed world. It is especially used for the printing of high quality barcodes. The thermal transfer print process uses three main components: a non-movable print head, a carbon ribbon (the ink) and a substrate to be printed, which would normally be paper, synthetics, card or textile materials. The three components form a sandwich with respect to the ribbon, which is in the middle. A thermally compliant print head, in combination with the electrical properties of the ribbon and the correct rheological properties of the ribbon ink are all essential components in producing a high quality printed image.

Print heads are sold in 203 dpi, 300 dpi and 600 dpi resolution options. Each dot is addressed independently and when a dot is electronically stimulated it immediately heats up to a pre-determined, (adjustable) temperature. The heated element immediately melts the wax or resin based ink on the side of the ribbon film facing the substrate and this process, in combination with the constant pressure being applied by the print head locking mechanism instantly transfers it onto the substrate. When a dot ‘turns off’ that element of the print head instantly cools down and that part of the ribbon thereby stops melting/printing. As the substrate comes out of the printer it is completely dry and can be used immediately.

Carbon ribbons are on rolls and are fitted onto a spindle or reel holder within the printer. The used ribbon is rewound by a take-up spindle forming a roll of used ribbon. It is called a ‘one-trip’ ribbon because once it has been rewound the used roll is discarded and replaced with a new one. If one were to hold a strip of used carbon ribbon up to the light one would see an exact negative of the images that have been printed. The main benefit of using a one-trip thermal transfer ribbon is that providing the correct settings are applied prior to printing, A 100% density of the printed image is guaranteed; compare this with a pre-inked ribbon on a dot matrix impact printer ribbon which slowly fades with usage.

Think Toner, Inc. has an excellent selection of Thermal Transfer products. Visit our website at www.thinktoner.com.