Diffraction Element Integration in Polymer Lamination

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The production of security documents with integrated diffraction elements, such as holograms, is complex and time-consuming due to sequential processing steps, leading to logistical challenges and a high risk of errors, requiring expensive equipment and complex systems.

Innovation Solution

Integrating diffraction elements directly into the lamination process of polymer laminates, eliminating the need for a separate gluing step, and using a carrier film with a photosensitive layer that is laminated together with other polymer layers to form a secure and efficient production method.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If diffraction elements are produced separately and then affixed to security documents, then the security features can be created with high precision, but the manufacturing process becomes complex and time-consuming

Engineering Contradiction:
Improvehologram precisionVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines the production of diffraction elements with the lamination process by integrating the photosensitive layer directly into the polymer laminate structure. The diffraction element is produced in-situ during lamination through photopolymerization, eliminating the need for separate production and affixing steps. This merging of operations reduces manufacturing complexity while maintaining hologram precision.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The photosensitive layer is pre-integrated into the polymer laminate structure before the lamination process begins. This preliminary preparation allows the diffraction element to be formed directly during lamination, avoiding subsequent separate affixing operations and reducing overall process complexity.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If diffraction elements are produced separately and then affixed to security documents, then the security features can be created with high precision, but the production time increases

Engineering Contradiction:
Improvehologram precisionVSAvoidproduction speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent merges the diffraction element production with the lamination process into a single simultaneous operation. The photosensitive layer is exposed and polymerized during the lamination process itself, creating the diffraction element in-situ. This eliminates the sequential steps of separate production and affixing, significantly reducing production time while maintaining hologram precision.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The lamination process is made continuous by integrating the diffraction element formation into the same operational sequence. The photosensitive layer is exposed and cured during the lamination process without interruption, maintaining continuous productive action rather than pausing for separate diffraction element production and affixing steps.

Inventive Principle:
Principle #20Continuity of useful action

3Strength

If additional adhesive materials are used to bond diffraction elements, then the bonding strength can be increased, but the security against forgery is reduced

Engineering Contradiction:
Improvebonding strengthVSAvoidsecurity against forgery
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent removes the adhesive material from the system by integrating the diffraction element directly into the polymer laminate structure. The diffraction element becomes an inherent part of the laminate rather than a separate component requiring adhesive bonding. This extraction of the adhesive eliminates potential security weaknesses while maintaining strong bonding through the integrated structure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent creates a composite structure where the diffraction element (photosensitive layer) is integrated within the polymer laminate matrix. This composite integration provides both structural strength and security, as the diffraction element becomes an inseparable part of the laminate rather than a separately bonded component that could be removed or replaced.

Inventive Principle:
Principle #40Composite materials

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

This approach simplifies the production process, reduces errors, and enhances security by creating a firm connection between the diffraction element and other layers without additional adhesive materials, making the documents more secure against forgery and reducing production time and costs.

Implementation Method 1

the photosensitive layer is exposed to light, such that a light-diffusing pattern is created in the photosensitive layer

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

produces visually perceptible phenomena that are either recognizable and/or can take on different forms depending on the angle from which the valuable or security product is viewed

Methodology Applied
Scientific EffectDiffraction: Diffraction

Data Source

PatentEP3490808B1Polymer laminate comprising at least one diffraction element and method for producing it
Publication Date: 2020.09.02 COVESTRO INTELLECTUAL PROPERTY GMBH & CO KG
  • EP3490808B1 patent drawingFigure 1~2
  • EP3490808B1 patent drawingFigure 3(A)~3(E)
  • EP3490808B1 patent drawingFigure 4(A)~4(E)

AI summary

To simplify the production method for a polymer laminate (100) comprising at least one diffraction element (160), a method with the following method steps is provided: (a) providing a diffraction element material (110), comprising a carrier film (150) and a light-sensitive layer (120) located thereupon, and also at least one polymer layer (170); (b) producing the at least one diffraction element (160) by creating a light-diffracting layer (122) from the light-sensitive layer (120), in that a light-diffraction pattern (125) is created in the light-sensitive layer (120) of the at least one diffraction element material (110); (c) bringing the at least one diffraction element (160) and at least one polymer layer (170) together to form a stack of layers (190); and (d) bonding the at least one diffraction element (160) and the at least one polymer layer (170) over the surface areas thereof by a laminating process, thereby forming the polymer laminate (100).