Color Change in Overlapping Layers via UV Activation

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Solution Overview

Problem

Current absorbent articles are limited in design options due to difficulties in registering colored regions on multiple components during manufacturing, requiring additional capital costs for new printing and registration capabilities, which restricts the creation of innovative designs with colored regions on multiple layers.

Innovation Solution

The method involves using overlapping layers with first and second activatable colorants that change color when exposed to UV light, allowing for simultaneous or sequential activation to produce visible color regions without the need for additional printing or registration capabilities, using materials like films, nonwovens, and adhesives.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If colored regions are disposed on multiple components or layers, then design space and visual appeal are improved, but manufacturing complexity and registration difficulty increase

Engineering Contradiction:
Improvedesign spaceVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The colorants are incorporated into the material layers during manufacturing, and the colored regions are activated by UV light after the layers are assembled. This preliminary incorporation of colorants without activation allows the layers to be manufactured and assembled first, then the visual design is created in a later step, eliminating the need for complex registration during assembly

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

UV light acts as an intermediary that activates the colorants in different layers independently. The UV activation process serves as a mediator between the manufactured layers and the final visual design, allowing colored regions to be created on multiple layers without requiring precise mechanical registration during assembly

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If printing capabilities are added to manufacturing lines for multiple layers, then colored region capability is improved, but capital cost increases

Engineering Contradiction:
Improvecolored region capabilityVSAvoidcapital cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

Instead of using multiple printing systems to create colored regions on different layers, the invention uses a single UV light source to activate colorants that are already incorporated into the layers. This replaces expensive physical printing infrastructure with a simpler light activation process, recovering capital costs while achieving multi-layer colored region capability

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The invention replaces mechanical printing systems with a light-based activation system. UV light substitutes for mechanical printing presses and registration mechanisms, eliminating the need for expensive capital equipment while achieving the same functional outcome of creating colored regions on multiple layers

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If registration capabilities are added to manufacturing lines, then colored region alignment is improved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvecolored region alignmentVSAvoidregistration capability
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

UV light serves as an intermediary that activates colorants independently in each layer without requiring mechanical registration. The light activation process mediates between the assembled layers and the final aligned colored regions, achieving precision through optical activation rather than mechanical alignment

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the parameter of colorant activation from mechanical (requiring precise physical positioning during printing) to optical (activated by UV light after assembly). This parameter change from mechanical positioning to light-based activation eliminates the need for complex registration capabilities while achieving colored region alignment

Inventive Principle:
Principle #35Parameter changes

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 enables cost-effective manufacturing of absorbent articles with richer color palettes and intricate designs on multiple layers, providing a permanent visual effect without the need for retooling existing manufacturing lines.

Implementation Method 1

The first and second activatable colorants are photoreactive material. The external stimuli are UV light.

Methodology Applied
Scientific EffectPhotoreaction: Photo-oxidation

Data Source

PatentEP2496198B1Method of producing color change in overlapping layers
Publication Date: 2019.12.25 PROCTER & GAMBLE CO
  • EP2496198B1 patent drawingFigure 1
  • EP2496198B1 patent drawingFigure 2
  • EP2496198B1 patent drawing

AI summary

The present invention relates to methods of producing color change in overlapping layers of material. The method comprises providing a first layer having a first activatable colorant and a second layer having a second activatable colorant. A first external stimulus is applied to activate the first activatable colorant and produce a first activated color region in the first layer. A second external stimulus is applied to activate second activatable colorant and produce a second activated color region in the second layer.