Control method for intaglio printing and control strip for that purpose

Patent metadata

Field	Value
Publication number	US-2016185100-A1
Application number	US-201314653622-A
Country	US
Kind code	A1
Filing date	Dec 20, 2013
Priority date	Dec 20, 2012
Publication date	Jun 30, 2016
Grant date	—

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

1 . A control process for intaglio printing, in particular for printing paper securities, such as banknotes, 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, characterized in that 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.

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 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 of varying depths.

10 . The process according to claim 9 , 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.

11 . 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.

12 . 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.

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

14 . A control strip intended for intaglio printing, in particular for printing paper securities, such as banknotes, 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, the control strip comprising a plurality of control areas intended to be engraved in a portion of the intaglio printing plate and to form, on the printed substrate, a corresponding plurality of printed control zones, said control areas being designed in such a manner as to allow in particular evaluation and measurement in said printed control zones of effects of the printing pressure applied during printing (iii) of the substrate as well as of effects of the ink coverage applied during inking (i) of the intaglio printing plate.

15 . The control strip according to claim 14 , wherein said control areas comprise a set of lines and/or curves of varying depths.

16 . The control strip according to claim 15 , wherein the depth of the lines and/or curves of said control areas varies within a range of values lower than or equal to 70 μm.

17 . The control strip according to claim 15 , wherein said control areas are designed to allow constitution of a sampling of measurements that are representative of printing of engravings of varying depths.

18 . The control strip according to claim 17 , wherein said control areas are designed to 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.

19 . The control strip according to claim 15 , wherein said lines and/or curves also exhibit varying line widths.

20 . The control strip according to claim 19 , wherein the line widths of said lines and/or curves vary within a range of values between 30 μm to 200 μm.

21 . The control strip according to claim 15 , wherein at least one control area amongst said control areas comprises lines oriented along a direction perpendicular to a printing direction.

22 . The control strip according to claim 15 , wherein at least one control area amongst said control areas comprises lines oriented essentially at ±45° with respect to a printing direction.

23 . The control strip according to claim 14 , wherein at least one control area amongst said control areas comprises a solid tone intended to allow measurement of optical density.

24 . The control strip according to claim 14 , wherein said control areas comprise:
at least one control area for controlling the printing pressure; and for each ink used, at least one control area for controlling balance between the printing pressure and the ink coverage.

25 . The control strip according t

Assignees

• Kba Notasys Sa

Inventors

• Chassot Daniel
• Heritier Raymond
• Voros Denis

Classifications

• B41F33/0045 Primary

  for automatically regulating the ink supply · CPC title

• B41F9/08 Primary

  Wiping mechanisms · CPC title

• B41N1/14

  Lithographic printing foils {(B41N1/003, B41N3/03 take precedence; compositions of the image-forming layer B41C1/10)} · CPC title

• B41M3/14

  Security printing {(securities B42D25/29)} · CPC title

• B41P2233/51

  for colour quality control · CPC title