RU1805444C - Method of manufacturing copies of cruciform projection screens - Google Patents

Abstract

SUMMARY OF THE INVENTION The invention consists in making a line raster template, applying a copy layer on a plate, copying a photo form of a line raster, etching and etching. Subsequently, the template is combined with a glass substrate on which a metal layer is applied by vacuum deposition of a given thickness. The degree of transparency of the opaque raster lines is controlled during the vacuum deposition of the metal. 1 sludge, 1 tablet

Description

The invention relates to the printing industry, and in particular to methods for manufacturing raster photoforms.

The purpose of the invention is to simplify the manufacturing process of cruciform projection rasters, and to expand the reproductive capabilities of manufactured cruciform projection rasters.

The drawing schematically depicts a process for manufacturing rasters.

The essence of the invention lies in the fact that a mask is made of copper foil and a copy layer is applied. The original linear raster is developed onto it, stained, and the resulting copy is duplicated. Its reverse side (foil) is cut out with acid-resistant varnish. The finished copy of the etch is then etched in an automatic etching machine for intaglio printing with a solution of ferric chloride, so that the lines of the copy that are not protected by an acid resistant layer are etched through.

The finished mask is combined with a defatted glass plate and placed in a vacuum unit. After creating the appropriate degree of rarefaction, the process of thermal evaporation of the metal in vacuum occurs. In this case, portions of the glass plate not protected by a free mask are metallized. After the mask is removed from the glass plate, the copy of the line pattern remains on it.

In order to obtain a copy of the cross-shaped raster, the mask is combined with a copy of the line raster so that the raster lines intersect at a given angle. Then, the vacuum spraying operation of the metal is repeated. The result is a copy of the cross-shaped projection raster with opaque or translucent raster lines, since the thickness of the sprayed metal layer is controlled during the vacuum spraying process, and it

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significantly affects the degree of transparency of raster lines.

The use of a mask makes it possible to make copies of projection rasters with varying degrees of transparency of raster lines. Moreover, in the process of vacuum spraying, it is possible to obtain a given degree of transparency of the raster lines, which gives 5 the expansion of the reproductive capabilities of copies of cross-shaped projection rasters. The invention also differs from the known technical solution in that the mask can also be used to make copies of cross-projection projections with varying degrees of transparency of raster lines. To do this, the mask is combined with a defatted glass plate and placed in a vacuum unit. After creating the necessary degree of rarefaction, the process of thermal evaporation of the metal in vacuum occurs, and the amount of evaporated metal is metered. This achieves the necessary degree of transparency of translucent raster lines.

In order to obtain copies of cross-shaped projection rasters with translucent raster lines, the above operations are repeated, and the amount of evaporated metal is varied in different directions to create a different degree of transparency of raster lines in different directions.

An example of a specific implementation of the method: a copper sheet is degreased (chalk + 5% H) on a copper foil with a thickness of up to 150 μm, a PVA-based copy layer is applied in a centrifuge at a rotor spindle rotational speed of 80 rpm and at a temperature of 40 ° C and dried in within 10 minutes; the thickness of the copy layer is 3 + 5 microns. After that, the foil coated with a copy layer is copied by a line raster for 2 min, with an illumination of about 20,000 lux. Manifestation in water for 1 min at a temperature of 38–40 ° Ci Staining in a solution of methyl violet for 3 min, washing in water for 1 min, tanning in a solution of chrome alum for 40 s. Rinsing in water for 1 min, firing at 180 ° C for 10 min. The back side of the foil is made acid resistant. To do this, it is coated with bakelite varnish or toluene paint.

A frame corresponding to the format of the mask is cut from the face of the copy made. After that, the copper foil is placed in an etching machine. Etching is carried out with ferric chloride, which has a density of 1.38.

The dependence of the etching time of the free mask on the etching conditions is presented in the table.

A method of making copies of projection rasters is reduced to the following operations: making a mask (as described above), preparing a glass base plate, aligning the free mask with the plate, vacuum spraying the metal onto a preheated glass plate, removing the free mask. The thermal evaporation of metals in vacuum is presented below.

Glass plate temperature: 80 ± 5 ° C.

Vapor pressure at melting point: aluminum: 1.2-10 mm Hg. st .; copper: 3.0 .st; chrome: 6.4 10 7mmrt.st. To make copies of the cross-shaped projection sockets, a mask is applied to the copy of the linear projection raster so that the raster lines intersect, for example, at a right angle. Next, vacuum deposition of the metal is performed and the mask is removed from the resulting copy of the cross-shaped projection raster.

The sequence of technological operations for making copies of cruciform rasters is as follows: 1 - metal foil, 2 - copy layer, 3 - original line raster, 4 - glass plate, 5 - sprayed metal layer. The resulting vacuum

By sputtering, a metal film, for example, chromium, already with a small thickness (150-200A) has a large (over 4.0) optical density.

This method of making copies

projection rasters allows you to produce not only copies of projection rasters with opaque raster lines, but also with lines having a different degree of transparency. In order to make copies of projection cruciform rasters with varying degrees of transparency of raster lines using this mask, the thickness of the sprayed metal layer, which controls the degree of transparency of raster lines, can vary depending on the amount of metal evaporated. The amount of evaporated substance is calculated according to the Langmuir equation:

0.0585uR / gsm2s 1 /,

where P is the vapor pressure in mmHg; M is the molecular weight; T is the absolute temperature.

Copies of cross-shaped projection rasters made by the proposed method can have a given degree of transparency of translucent raster lines, which allows expanding their reproduction capabilities compared with copies of cross-projection raster lines that have completely opaque raster lines.

Claims (1)

SUMMARY OF THE INVENTION A method of making copies of cross-shaped projection rasters, which consists in making a mask by applying a copy layer to a substrate, copying on this substrate a ruled original raster followed by etching, forming the glass plate by means of a mask a copy of the projection cross-shaped raster, including vacuum deposition of the metal layer and etching, characterized in that in order to simplify the process and expand the technological capabilities of the method by obtaining copies with raster lines having different degrees of transparency Before vacuum deposition, the mask is combined with a copy of the projection line raster with the intersection of the raster lines at a given angle, while the thickness of the sprayed layer 5 vary depending on a predetermined degree of transparency of the raster lines, with metal foil being used as a substrate. MP I D. „- -Rahj L gru MbSL. -EWRvgM ---- Vitesg M-. E - 1 3L i 9 2 i 2 i