Label Ink Layer Structure Mitigating Water-Based Ink Repellence

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Solution Overview

Problem

Direct application of water-based ink on synthetic resin-based label base materials often results in poor ink layer formation due to ink repellence, especially with high water content, and surface treatments like corona discharge pose safety and handling issues.

Innovation Solution

A label structure comprising a base material with a dyne level of 40 mN/m or less, a directly formed water-based ink layer with 50-95% halftone dot reproducibility, a first oil-based ink layer covering the water-based ink, and a second oil-based ink layer covering both, enhancing appearance without special surface treatments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If water-based ink is directly applied on synthetic resin label base material, then the manufacturing process is simple, but the ink layer formation is poor due to ink repellence

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidink layer formation quality
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent introduces an oil-based ink layer as an intermediary between the water-based ink layer and the synthetic resin label base material. This oil-based layer acts as a mediator that improves ink adhesion and prevents repellence, allowing the water-based ink to be properly formed on the non-polar synthetic resin surface without requiring complex surface treatments.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If corona discharge treatment is performed on label base material to improve wettability, then ink application uniformity is improved, but blocking occurs making handling difficult

Engineering Contradiction:
Improveink application uniformityVSAvoidlabel handling ease
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The patent uses an oil-based ink layer as an intermediary that bridges the compatibility gap between water-based ink and synthetic resin, eliminating the need for corona discharge treatment. This approach maintains label handling ease while achieving uniform ink application through the mediating properties of the oil-based layer.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If corona discharge treatment is performed immediately before ink application, then ink repellence is reduced, but safety issues arise in the manufacturing process

Engineering Contradiction:
Improveink repellence reductionVSAvoidmanufacturing process safety
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the hazardous corona discharge process with a safe oil-based ink layer application process. The oil-based layer serves as a mediator that reduces ink repellence without requiring electrical discharge, thereby eliminating safety concerns while achieving the same ink adhesion improvement.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Stability of the object's composition

If water-based ink with high water content is used, then the ink layer has good flexibility, but ink repellence on synthetic resin increases

Engineering Contradiction:
Improveink layer flexibilityVSAvoidink layer formation completeness
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent introduces an oil-based ink layer as a mediator between the high-water-content water-based ink and the synthetic resin substrate. This intermediary layer enables the flexible water-based ink to adhere properly to the non-polar synthetic resin surface, achieving both ink layer flexibility and complete coverage.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution ensures uniform ink application and clear display of characters and patterns by mitigating ink repellence and irregularities, improving label appearance without requiring surface treatments.

Implementation Method 1

a water-based ink layer directly formed on the label base material and having a halftone dot reproducibility of 50 to 95%

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Implementation Method 2

a first oil-based ink layer formed above the label base material so as to cover the water-based ink layer; and a second oil-based ink layer formed above the label base material so as to cover the water-based ink layer and the first oil-based ink layer

Methodology Applied
Scientific EffectLayer formation: Deposition (physical)

Data Source

PatentEP3640924B1Label and method for manufacturing label
Publication Date: 2022.07.20 FUJI SEAL INTERNATIONAL INC
  • EP3640924B1 patent drawingFigure 1~2
  • EP3640924B1 patent drawingFigure 3~4
  • EP3640924B1 patent drawingFigure 5~6

AI summary

A label 10 that is an example of an embodiment of the present invention is provided with: a label base material 11 with a dyne number of 40 mN/m or less; a water-based ink layer 13 formed directly on the label base material 11 and having a dot reproduction rate of 50-95%; a foundation solvent-based ink layer 14 formed above the label base material 11 while covering the water-based ink layer 13; and an solvent-based ink layer 15 formed above the label base material 11 while covering the water-based ink layer 13 and the foundation solvent-based ink layer 14.