SU1397546A1 - Method of reconditioning intaglio printing from cylinder - Google Patents

Abstract

The invention relates to electroforming, in particular to the recovery of a removable copper coating of a gravure printing cylinder and can be used in printing. The purpose of the invention is to accelerate the process of reducing the consumption of copper while maintaining high quality of the copper coating and preventing nickel pickling. Galvanic restoration involves removing the worn-out coating from the nickel-plated copper base of the working cylinder and re-building it in the same copper bath with an insoluble electrode. the build-up is carried out at a current density on an insoluble electrode of 1-12 A / dm. Glass-carbon mark SC 1300 or carbon fiber cloth of mark УОТ-2 is used as an insoluble electrode. The method provides for increasing the working copper coating with a thickness of 40-70 µm while maintaining the quality of the coating and reducing the consumption of copper without etching the nickel sublayer. i (Л С

Description

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 The invention relates to electroforming, in particular, to the restoration of a removable copper coating of an intaglio printing cylinder, and can be used in printing.

The purpose of the invention is to accelerate the process and reduce the consumption of copper, while maintaining the high quality of the copper coating and preventing nickel from being rastroplating.

The galvanic restoration of a gravure printing cylinder includes removing the worn-out copper coating from the nickel-plated copper base of the working copper cylinder and building it again in the same copper bath with an insoluble electrode. The worn-out working copper coating is removed when a potential of 0.2-0.3 V is applied to the cylinder, and the build-up is carried out at a current density of 1-12 A / dm on an insoluble electrode, and glass carbon is used as an insoluble electrode.

For carrying out the process, a glassy carbon material of grade SU 1300 or carbon fiber fabric of the mark is used. FAT-2.

A nickel sulfamic acid coating is applied between the copper base of the cylinder and the working copper layer; electrolyte "

The implementation of the proposed method of galvanic restoration allows; L et to obtain a high-quality re-I working coating with a hardness of 101-: 147 MPa and a roughness of 0.3-0.6 μm

The method involves increasing the working copper coating with a thickness of 40-70 µm, which significantly reduces the duration of the process of manufacturing the printing form as a whole.

Example 1. A gravure cylinder for intaglio printing, 1 representing a steel nickel-plated base with a galvanically deposited base copper layer with a thickness of 300 µm and. The working copper layer, 40 microns thick, between which the nickel layer is located, undergoes restoration, including the removal of the worn-out copper coating and the re-buildup of the working copper coating in the same galvanized copper with insoluble electrode. Copper electrolyte contains, g / l:

Copper sulfate 180

Acid chamois 75

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Electrolyte temperature is 25 C.

The process of removing a worn copper working coating from a nickel-plated copper base is carried out when a potential of 0.2 V is applied to the plate cylinder. In this case, a glassy carbon material SU 1300 is used as an insoluble electrode, which acts as a cathode in the removal process .

Then, in the same bath, the working copper coating is re-expanded, for which the polarity of the electrodes is changed, while the insoluble electrode acts as an anode, which exhibits a current density of 12 A / dm.

The build-up process is carried out until a working copper coating with a thickness of 40 µm is obtained.

Example 2. A gravure printing cylinder is a nickel-plated steel substrate with a deposited main copper layer 200 µm thick and a 70 µm copper working layer, between which there is a nickel layer, subjected to galvanic restoration, including the removal of a worn-out coating and the re-build-up of copper copper coating in the same copper bath with an insoluble electrode. Copper electrolyte contains, g / l:

Copper sulfate 200

Sulfuric acid. 80

The temperature of the electrolyte is 30 ° C.

The process of removing the working copper coating from the nickel-plated copper base of the cylinder is carried out when a potential of 0.3 V is applied. In this case, the carbon fiber fabric of the UOT-2 brand, which acts as a cathode in the process of removing the coating, is used as an insoluble electrode.

Then, in the same bath, the working copper coating is re-expanded, for which the polarity of the electrodes is changed and the insoluble electrode (carbon fiber cloth) acts as an anode at which the current density is 1.0 A / dm. The build-up process is carried out to obtain a working copper thickness, with a coating of 70 µm.

The obtained copper coatings are subjected to hardness tests on a microhardness meter and on microroughness on a profilograph-profilometer.

313975464

The microroughness was 0.3 nt of a cylinder of worn copper and 0.6 microns, and the microhardness was 147 and dredge and its subsequent galvanic 101 MPa, respectively, according to examples. . Some capacity in one bath is so that the proposed method, either using an auxiliary, allows to quickly restore it. insoluble electrode, about tl and h a is a removable copper coating of formic cyi u and, so that, in order to accelerate the intaglio printing while maintaining the process’s rhenium while maintaining the high quality of the coating without etching the quality of the copper coating - a nickel sublayer, preventing nickel pickling,

the removal of the copper coating is carried out at a formula from finding the potential of the form cylinder 0.2-0.3 V,

and the build-up - at current density on

The method of restoration of the form of a 1-12 A / dm mold-insoluble electrode, an intaglio printing chip, including the removal of s as an insoluble electrode with copper-coated nickel, mainly uses glass carbon.

Claims (1)

Claim The method of restoration of the gravure printing plate cylinder, including the removal of a worn copper coating cylinder with a nickel-coated copper base and its subsequent galvanic build-up in a single copper plating bath using an auxiliary insoluble electrode, such that in order to accelerate the process while maintaining the high quality of the copper coating and to prevent nickel pickling, the removal of the copper coating is carried out with the potential of a plate cylinder of 0.2-0.3 V, and the build-up is performed at a current density of rome electrode 1-12 A / DM ² , 15 and as an insoluble electrode using glassy carbon.