Control process for intaglio printing and control strip for this purpose

Patent metadata

Field	Value
Publication number	US-10150283-B2
Application number	US-201314653622-A
Country	US
Kind code	B2
Filing date	Dec 20, 2013
Priority date	Dec 20, 2012
Publication date	Dec 11, 2018
Grant date	Dec 11, 2018

Abstract

It is especially described a control process for intaglio printing, in particular for printing paper securities, such as banknotes. This control process includes defining on an intaglio printing plate (80) control areas (150, 151-155; 170, 171-179) designed in such a manner as to allow in particular evaluation of effects of the printing pressure applied during printing of a substrate by means of the intaglio printing plate (80) and evaluation of effects of the ink coverage applied during inking of the intaglio printing plate (80), which control areas (150, 151-155; 170, 171-179) are engraved in a portion of the intaglio printing plate (80) in order to produce corresponding printed control zones (160, 161-165) on the substrate. The process further includes carrying out of measurements in the printed control zones allowing evaluation of the printing pressure applied during printing of the substrate as well as of the ink coverage applied during inking of the intaglio printing plate (80).

First claim

The invention claimed is:

1. A control process for intaglio printing, for printing paper securities, said intaglio printing involving:
(i) inking of at least one intaglio printing plate with at least one intaglio ink;
(ii) wiping of the intaglio printing plate thus inked; and
(iii) printing of a substrate by means of the intaglio printing plate thus wiped, printing of the substrate involving application of the substrate against the intaglio printing plate at a printing pressure,
printing pressure, ink coverage and wiping constituting printing parameters that are liable to affect said intaglio printing,
wherein the control process comprises the following steps:
(a) defining on the intaglio printing plate control areas designed in such a manner as to allow in particular evaluation of effects of the printing pressure applied during printing (iii) of the substrate and evaluation of effects of the ink coverage applied during inking (i) of the intaglio printing plate, which control areas are engraved in a portion of the intaglio printing plate in order to produce corresponding printed control zones on said substrate;
(b) carrying out measurements in said printed control zones allowing evaluation of the printing pressure applied during printing (iii) of the substrate; and
(c) carrying out measurements in said printed control zones allowing evaluation of the ink coverage applied during inking (i) of the intaglio printing plate,
wherein said control areas are subdivided into four quarters having line depths and the line depth is different for each quarter, wherein said quarters of at least one of said control areas comprise a set of lines and/or curves of varying depths in a range of values lower than or equal to 40 μm, wherein the measurements carried out in that printed control zone allow constitution of a sampling of measurements that are representative of printing of engravings of varying depths.

2. The process according to claim 1 , wherein the printing pressure and the ink coverage are adjusted until the measurements carried out in said printed control zones reflect an optimal balance between the printing pressure and the ink coverage.

3. The process according to claim 1 , wherein the intaglio printing plate is inked by means of a plurality of different inks, said control areas comprising at least one control area for each ink used,
and in that the measurements carried out in said printed control zones are undertaken for each ink individually.

4. The process according to claim 1 , wherein the measurements carried out in said printed control zones include measurement of raggedness, measurement of fill, and measurement of optical density in accordance with a determined measurement standard.

5. The process according to claim 4 , wherein said determined measurement standard is the ISO/IEC 13660:2001 standard or the ISO/IEC TS 24790:2012 standard.

6. The process according to claim 4 , wherein the measurement of raggedness, the measurement of fill, and the measurement of optical density are carried out on printed lines substantially oriented at ±45° with respect to a printing direction.

7. The process according to claim 6 , wherein the printed lines on which the measurement of raggedness, the measurement of fill, and the measurement of optical density are carried out exhibit a line width ranging between 30 μm and 200 μm.

8. The process according to claim 4 , wherein the measurements carried out in said printed control zones further include the measurement of a contrast.

9. The process according to claim 1 , wherein the measurements carried out in said printed control zones allow constitution of a sampling of measurements that are representative of printing of engravings the depth of which varies within a range of values lower than or equal to 70 μm.

10. The process according to claim 1 , wherein it further comprises a step which consists in verifying printability of a security pattern which is to be printed by intaglio printing by means of the intaglio printing plate, once a printer has carried out a desired setting of said printing parameters.

11. The process according to claim 1 , wherein the printing parameters of an intaglio printing press are controlled and, if need be, adjusted according to the measurements carried out in the printed control zones.

12. The process according to claim 1 , wherein the control areas comprise control areas of a control strip located in a margin of a security pattern and/or control areas defined directly within the security pattern.

Assignees

• Kba Notasys Sa

Inventors

• Chassot Daniel
• Heritier Raymond
• Voros Denis

Classifications

• B41F9/063

  Using inking rollers · CPC title

• B41F9/08 Primary

  Wiping mechanisms · CPC title

• B41P2233/51

  for colour quality control · CPC title

• B41F9/021

  Sheet printing presses · CPC title

• B41F33/0045 Primary

  for automatically regulating the ink supply · CPC title