Thermographic printing

Thermal relief printing (also thermography or thermal ) is a finishing process for print, the writing and drawing in relief lifted off the paper. The technique came in the late 1970s from the U.S. to Europe.

History

The print - finishing processes thermal relief printing is to replace the expensive and complex historic steel engraving or embossing at favorable prices. Result is to the printing medium (paper) raised standing writing or drawing, the slightly arched and relief stands out from the background in both methods. The most common usage are higher quality business cards or letterhead.

While the classic steel engraving this result obtained by wrong- engraving the drawing or the letter in a metal plate and then printing in letterpress (high pressure), the high curvature pressure came through strong (physical), the thermal relief printing is a chemical way by heating a plastic granules.

Technology

The preferably in offset printing as well as screen printing or letterpress produced, fresh deduction is strewn with plastic granules, which combines with the respective, still wet ink, but can be sucked from the bare paper base. You can also narrow the granules in the pearlescent pigments. In a subsequent heat treatment in an infrared heater colorless powder blends with the wet ink, swells, dried and then forms the desired relief-like, about 0.2 mm high elevation, which is visually and haptically perceived as " expensive, posh ".

For thin lines and small letters is fine granule, used for surfaces and stronger image elements granules with coarse grain, the grain size corresponding to the thickness of the relief. However, the thermal relief process does not reach the sharpness of steel engraving. It is essential that only solid colors are suitable for thermal relief printing, shaded or 4- color prints are not technically. Multicolored thermal relief prints are possible in abutting colors must be ensured a positive pressure to " speed traps" to avoid. The maximum print size is limited to A4 size ( in exceptional cases A3 ). As printing material smooth, non- absorbent papers from 90 g / m are suitable.