Sublimation printing (process)

Sublimation printing or transfer printing refers to the printing process in which the dye is evaporated ( sublimed ) into the carrier . For this to be transfer papers and sheets, as well as dyes or special inks used, which is usually on synthetic fibers are sublimated. Transfer printing was introduced as a new printing process in the late 1960s.

Procedure

First, a paper web or a special film is printed with suitable dyes (reversed) and then transferred to the carrier material with a thermal transfer press in the transfer printing process by heating to up to 230 ° C. The prerequisites are that the dyes sublime at a sufficient rate in the range from 170 to 230 ° C and diffuse into the fiber and adhere well to the fiber. Disperse dyes (e.g. azo dyes and anthraquinone dyes ), which are water-insoluble, are used. The main advantages of sublimation printing are that different materials can be printed in photo quality, the comparatively low costs and better environmental compatibility. There is no need for binding agents and solvents , which can be present in the fiber with other printing processes and which would have to be washed out. In addition, the print is very resistant to UV radiation and other environmental influences.

Normal inkjet printers with special inks are also used for sublimation printing . After the transfer to the material to be printed, no color application is felt during sublimation printing, as the ink completely evaporates into the material.

Materials that are intended for sublimation printing are, for example, T-shirts or necklaces and bracelets. They are often made of polyester or are covered with a polyester layer. Other possible fibers are those made of polyamide , polyacrylonitrile and cellulose acetate . Natural fibers from cotton and wool are less suitable. However, transfer printing is successful if the fibers are prepared beforehand (e.g. with swelling agents). Carriers with a polymeric coating such as wood, aluminum, glass or ceramics can also be printed using sublimation printing.

In the wet transfer process, dyes that cannot be sublimated can also be used. The dyes get onto the textile through water vapor .

literature

Artur Haus: The transfer printing, chemistry in our time , 12th year 1978, No. 2, pp 41-48, ISSN  0009-2851