Security Element Spacer Grid for Wash Process Control

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Solution Overview

Problem

The existing washing process for producing security elements can fail to create the desired recess pattern when the substrate contains embossed structures with little or no height variation, leading to unintentional deposition of wash-ink toning film.

Innovation Solution

A method involving a carrier with an embossing lacquer layer, where large-area partial areas of effect embossing are formed with a dot and/or line grid of small spacer structures, which are not visually recognizable. These spacer structures have lateral dimensions of more than 2 µm and are designed to prevent unwanted wash-ink deposition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a washing process is used to create recess patterns on embossed structures, then the desired recess pattern can be created in printed areas, but unintentional wash-ink toning film deposition occurs in large-area embossed structures with little height variation

Engineering Contradiction:
Improverecess pattern creationVSAvoidunintentional wash-ink toning film deposition
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The invention divides the large-area embossed structure into a grid of smaller sub-areas using spacer structures. This segmentation prevents the wash-ink from forming continuous toning films across large flat areas, as the spacer structures create physical barriers that limit ink spread and promote proper recess pattern formation in each segmented zone.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The spacer structures act as intermediary elements between the wash-ink application and the embossed structure. These spacers modify the wash-ink flow and distribution, preventing direct unwanted contact and toning film formation while allowing the desired recess patterns to develop in the printed areas between spacers.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Area of stationary object

If the substrate contains embossed structures with little or no height variation, then large contact area is created with wash-ink cylinder, but this leads to unintentional wash-ink toning film deposition

Engineering Contradiction:
Improvecontact area with wash-ink cylinderVSAvoidwash-ink toning film deposition
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

By introducing a grid of spacer structures across the embossed area, the invention segments the continuous contact area into discrete smaller zones. This prevents the wash-ink cylinder from creating continuous toning films across large flat areas, as each segmented zone between spacers allows proper drainage and recess formation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The spacer structures create local variations in the embossed surface topology, transforming uniformly flat areas into locally differentiated zones. Each zone between spacers has controlled properties that promote proper wash-ink behavior, while the spacers themselves create physical barriers that prevent unwanted ink accumulation in specific locations.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method reliably produces large-area, structured partial areas in the washing process, ensuring the desired recess pattern is created without unintended wash-ink toning film deposition, thus enhancing the security and authenticity of the security elements.

Implementation Method 1

the embossing lacquer layer is provided with a desired effect embossing, in particular a micromirror embossing or a hologram embossing

Methodology Applied
Scientific EffectOptical reflection and diffraction: Reflection

Implementation Method 2

The ink application and the overlying top layer can then be removed by washing with a suitable solvent, so that recesses in the form of the printed pattern are created in the top layer

Methodology Applied
Scientific EffectSolvent washing: Solvation

Implementation Method 3

large-area partial areas of the effect embossing, which are to remain uncoated during the subsequent color printing, are formed with a dot and/or line grid of small spacer structures, which is not visually recognizable when viewing the security element with the naked eye and in which the spacer structures have lateral dimensions of more than 2 μm in every spatial direction

Methodology Applied
Scientific EffectSurface area reduction effect:

Data Source

PatentEP3959082B1Method for producing a security element, and security element
Publication Date: 2025.05.28 GIESECKE & DEVRIENT CURRENCY TECHNOLOGY GMBH
  • EP3959082B1 patent drawingFigure 1(a)~2
  • EP3959082B1 patent drawingFigure 3(a)~4
  • EP3959082B1 patent drawingFigure 5~6

AI summary

The invention relates to a method for producing a security element (10), in which a substrate (12) is provided with an embossing lacquer layer (14) and the embossing lacquer layer (14) is provided with a desired effect embossing (16), in particular a micromirror embossing (40) or a hologram embossing (16), a wash-out dye is applied in some regions to the embossed embossing lacquer layer (14) by means of wash-out dye printing (20), and a top layer is applied to the area of the embossing lacquer layer provided in some regions with wash-out dye, and then the wash-out dye is removed together with the top layer disposed thereon. In accordance with the invention, large areas of the effect embossing (16) that should remain uncoated at the time of the subsequent wash-out dye application are formed with a grid of dots and/or lines (30) formed from small spacer structures (32), which grid is not visually perceptible when the security element (10) is observed with the naked eye, and the spacer structures (32) have lateral dimensions of more than 2 µm in each spatial direction. The invention further relates to a correspondingly produced security element (10).