UV Film Casting
What is UV Film Casting
In the graphic arts industry, UV film casting is used as a technology to transfer holographic patterns on top of printed images. Different from cold foil there’s no transfer layer being applied to the sheet. It is more or less a micro embossing of a holographic pattern.
As the holographic pattern is “embossed” into the coating surface pressure from the following units will flatten this effect and make it disappear. This is why the technology is used very often in the last coating unit at the end of the press. When applying the effect in a different section of the press (e.g. printing unit) the pressure in the following units should be switched off.
UV Film Casting
The UV coating can be applied partly or in solids from a printing unit using an offset plate or from a coating unit using a striped blanket or a flexo plate.
During the transfer of the pattern, the holographic texture of the foil comes in contact with the wet UV coating on top of the printing sheet. During this contact, the UV coating is being cured through the transparent holographic film. The result is a vice versa of the holographic film pattern on the printed sheet.
After the pattern has been transferred and the UV coating has been cured the plastic film is released from the sheet surface. The plastic film for UV film casting can be used multiple times until the pattern on the plastic is fading away or the plastic film gets worn. The number of passes is depending on different parameters such as intensity of UV rays, type of coating, amount of coating, etc.