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Print Components for Thermal Transfer Printing
The main component for thermal transfer printing is the thermal print head. This
mechanism provides the heat energy required to create the image on the print media.
Thermal print heads are fixed in position and the media moving past the print head
to create the image. For this reason the print head and he print ribbon are as
wide as the media on which they are printing. The print head is a very simple mechanism and does not require a scanning mechanism.
The print accuracy on thermal transfer printers is superior because the print element
position is fixed to the web motion direction. The spacing of the print elements
on the linear array print head can be held to a tolerance of 0.0001 inch, making
thermal transfer printers an accurate method of printing. This is especially significant
for machine-readable bar codes. When bar code labels are printed vertical to the print head motion, the print accuracy
is dependent on the accuracy of the print head motion. In addition, the print quality
of the image edge is affected by the time needed to heat the printing elements for
the thermal ink to melt, as well as the time needed to cool the elements so that
they will not melt the ink. The association between the print head and the platen located behind the print media
is significant for the proper operation of the printer. It is important that the
thermal printing elements are located vertical to the center-point of the cylindrical
platen. Also critical to the printing process is the pressure between the print
head, ribbon, and print media. When the print elements are not positioned on the
centerline of the cylindrical platen, the printing elements will not produce the
exact size dot on the printed media, thus the printed image will be smudged or poor
quality. Thermal transfer printer heads have a longer life than direct thermal printers do
because they use approximately 33% less energy to produce the same quality image.
In addition, the coating, and base layer of the thermal transfer ribbon prevents
the ink from adhering to the print head. As the thermal transfer ribbon and the ink receiving media is moved past the print
head a microprocessor selectively heat individual resistive print head elements
to create the image. By alternating the movement of the print media, and selectively
heating the wax residue, a matrix of individual dots is created and an image is
produced.
Small business guides: , Thermal Transfer Labels Guide.com |
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