Sealing of a metal surface can be necessary at production of outdoor advertizing, elements of an interior, plates, award diplomas and representative branded production, technical details, packing, ware, Souvenirs, and also sometimes metal inserts use at development of models of printing production.
The main problem that makes it difficult to apply printed images to metal products is that this material does not absorb moisture. Everyone knows that any paint consists of a solid pigment, which gives it a certain color, and a liquid binder, which partially evaporates and absorbs into the printed material, contributing to the consolidation of the impression.
The solution to the problem was ultraviolet curing paints, which instantly dry under the influence of UV radiation. Another possibility is given by the properties of the metals themselves: since this material is resistant to heat, when printing, you can use roasting to bake the paint on the surface, which is difficult in the manufacture of printing from paper.
Image transfer to metal is carried out in several ways, we will talk about them in more detail.
Silk screen printing (screen printing)
Silkscreen allows you to seal both flat metal plates and convex surfaces. The essence of this method is that the impression is formed by pushing the paint through the printing plate-a thin polymer mesh stretched on a metal frame. On this form, the printing elements are free, and the blank ones are clogged during the exposure and development of the photoform. Silkscreen allows you to create multi-color halftone images on metal, and using not only triad colors, but also the Pantone palette.
With the help of silk screen, metal instrument panels, nameplates, plates and badges, beardekels, Souvenirs, some types of outdoor advertising, etc.are made. This method is beneficial in the production of printing products in small editions.
Direct printing on metal
Direct inkjet printing is carried out by means of UV printers and large-format plotters. Direct printing can be done with UV-curing ink or heat-resistant ink, for fast fixing of the print is used respectively UV-or heat drying.
This relatively new technology has found its application in the production of metal elements of the interior and exterior, outdoor advertising, corporate Souvenirs, nameplates, plates, etc.
An important advantage of direct printing on metal is the independence of the cost of one product from the circulation of printed products.
Pad printing on metal
Pad printing technology is simple as all ingenious, but the development of layouts of printing products and the printing process itself requires great care and experience. For transfer of a logo or other information the printing form (any: for the high, deep or flat press) and a special elastic tampon is used. The form is installed in a horizontal plane next to the colorful apparatus, the tampon is fixed in the tampon holder. During one printing cycle, the ink is fed to the mold, the tampon comes into contact with the printing elements and transfers the paint to the product, fixed with a snap.
The main disadvantage of this method is that the dimensions of the tampon, and therefore the transferred pattern, are limited.
Technological capabilities of pad printing: penetration into hard-to-reach places, printing on a convex surface-allow to apply this method in different industries: the production of instrument panels, control units, toys, Souvenirs, packaging and other printing products.
Sublimation on metal (graverton, colorton, etc.)
This technology is a transfer of information through an intermediary-an ordinary sheet of paper. The bottom line is that the developed layout of printing products is printed on paper using a conventional printer, filled with a special toner for sublimation. Then the sealed paper is placed face down on a metal sheet with a polymer coating and placed this “sandwich” in a thermal press. Under the influence of high temperature, the toner sublimates (passes from a solid state to a gaseous state) and penetrates into the micropores of the metal.
This technology is similar to thermal transfer, in which the transfer of the picture on different surfaces is made using an intermediate carrier-a special thermal transfer paper.
This method produces various plates, diplomas, badges and other products that have a flat surface.
Sublimation allows you to make products from a single copy. The disadvantage of this technology is that the transferred image is unstable to the influence of sunlight.