Method for production of offset printing plate

FIELD: printing arts, in particular, method for production of offset printing plate.

SUBSTANCE: the method consists in the fact that for formation of the spacing materials of the printing plate the surface of an aluminum plate is subjected to action of laser radiation of the ultraviolet range with an exposion providing for appearance of additional water molecules and groups C=0 on the surface as a result of chemosorption.

EFFECT: reduced number of production operations and reduced power consumption at production of the plate.

 

The invention relates to printing, and more particularly to plate processes of offset printing.

A known method of manufacture of offset printing plates [1], based on the exposure of aluminum plates with pre-applied hydrophilic coating and moisturizing solution. The exposure is carried out in the laser facility, managed computer. The laser beam impinging on the plot of the plates, causing its heating and evaporation of the fountain solution, as well as the destruction of the hydrophilic coating. Then the form is rolled paint, which is perceived by the areas destroyed by the coating, the result is the formation of the printing elements. The spacing elements are areas with intact hydrophilic layer with a moisturizing solution.

In the described method of manufacture of offset printing plates required is pre-coated aluminum plates hydrophilic layer followed by the application of the fountain solution. The length of the printing plate obtained in this manner is limited by the properties of the hydrophilic coating and the resistance of the fountain solution to rolling paint, as well as to mechanical impact in the printing process.

The proposed method for the manufacture of offset printing plates, consisting in that the aluminum plate, no light Il is heat-sensitive layer, exposed to the influence of ultraviolet laser beam controlled by a computer. Due to exposure to UV radiation exposure of 7.2·104W/m2·c on the surface of aluminum additional water molecules resulting from the chemisorption of molecules of water vapor in accordance with the scheme of H2O+Z↔H2OZ, where Z is the center of chemisorption. Hammarbyhamnen water molecules interact with hammarbyhamnen on the surface of the aluminum oxide, oxygen (Ob-and form a hydroxyl group - IT scheme:

H2OZ+(O)Z↔HOZ+ZOH.

In addition, on the surface of the aluminum present in the group C=O. Thus, additional water molecules and groups C=O, associated with the surface in varying degrees, cause significant increase in hydrophilicity of the surface of the irradiated aluminum.

The surface of the aluminum plate, is not affected by UV exposure, are hydrophobic (print), plots treated with ultraviolet radiation, hydrophilic (whitespace). After exposure to the surface of the aluminum plate is applied hydrophilicity solution, which is strongly linked with the hydrophilic areas of the aluminum plate, forming a gap elements offset form. Then on the shape of the applied offset based paint, vos is minimuma only hydrophobic parts of the surface, representing printed items offset form.

Thus, the proposed method of manufacture of offset printing plates provides a reduction in the number of technological operations: electroplating granulation aluminum plates, coating the photosensitive layer, the manifestation and the drying of offset printing plates, which in turn leads to a reduction in the number of used equipment and reduce energy consumption.

Sources of information

1. Spanoulis NI Plate and printing processes (technology and systematization), book 1. - M.: Book, 1989.

The method of manufacture of offset printing plates, which consists in the fact that on the surface of the aluminum plate exposed to laser radiation, characterized in that for forming the gap elements on the surface of the aluminum plate exposed by laser UV radiation exposure, providing the appearance on the surface as a result of additional chemisorption of water molecules and groups.



 

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