Polyurethane Label with Thermally Activated Adhesive

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Solution Overview

Problem

Existing label technologies face challenges such as complex production processes, environmental and safety hazards, limited design flexibility, and disposal issues, particularly with self-adhesive and shrink-sleeve labels, which restrict material choice and aesthetic appeal.

Innovation Solution

A label with a non-tacky polyurethane adhesive layer that becomes tacky upon activation by external energy, such as heat, allowing for reversible tackiness and eliminating the need for a release liner, enabling simpler labeling processes and improved bond strength, water resistance, and design versatility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If self-adhesive labels with pressure-sensitive adhesive are used, then labels can be applied easily, but the production process becomes complex and release liner disposal becomes a major environmental issue

Engineering Contradiction:
Improvelabel applicationVSAvoidproduction process
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the release liner component from the label system. The adhesive layer is applied directly to the substrate without requiring a release liner, thereby simplifying the production process and eliminating the disposal issue while maintaining easy label application through the self-adhesive mechanism.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The label structure is segmented into essential components only: substrate and adhesive layer. By removing the non-essential release liner component, the production process is simplified and environmental disposal issues are eliminated while the core function of easy application is preserved through the direct adhesive-substrate bonding.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If wet-glue labels are used, then adhesive application is simple, but the process becomes messy and requires extensive clean-up time

Engineering Contradiction:
Improveadhesive applicationVSAvoidclean-up time
Core Design Contradiction:
Ease of manufactureVSLoss of time

Solution Approach 1:

The invention replaces the wet mechanical adhesive application process with a dry adhesive layer that is pre-applied to the substrate. This substitution eliminates the messiness and clean-up requirements associated with wet glue application while maintaining simple adhesive bonding functionality.

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

Solution Approach 2:

The adhesive layer is preliminarily applied to the substrate during manufacturing, creating a ready-to-use label that requires no additional adhesive application at the point of use. This preliminary action eliminates the need for messy wet glue application and extensive clean-up time during label deployment.

Inventive Principle:
Principle #10Preliminary action

3Area of stationary object

If shrink-sleeve labels are used, then full surface coverage is achieved, but the production process becomes complex and expensive

Engineering Contradiction:
Improvelabel coverage areaVSAvoidproduction process
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the complex shrink-sleeve mechanism from the labeling system. By using a simple self-adhesive label structure, the production process is dramatically simplified while still achieving effective surface coverage through direct adhesive bonding to the substrate.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using a shrink-sleeve that contracts around the substrate, the invention inverts the approach by using a flat label with adhesive that bonds directly to the substrate surface. This inversion simplifies the production process while achieving the same functional goal of surface coverage.

Inventive Principle:
Principle #13The other way round (Inversion)

4Stability of the object's composition

If non-tacky adhesive is used, then the label can be stored without blocking, but the label cannot be applied without additional activation steps

Engineering Contradiction:
Improveadhesive non-blockingVSAvoidlabel application
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The invention utilizes parameter changes in the adhesive properties through thermal activation. The adhesive transitions from a non-tacky state during storage (preventing blocking) to a tacky state during application (enabling bonding) through controlled temperature changes. This parameter change resolves the contradiction between storage stability and application ease.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The adhesive properties are made dynamic rather than static. The adhesive transitions between non-tacky and tacky states based on thermal conditions, allowing the label to maintain storage stability while enabling easy application when activated. This dynamic behavior resolves the contradiction between non-blocking storage and effective application.

Inventive Principle:
Principle #15Dynamics

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 simplifies labeling processes, reduces waste, allows for sensitive material labeling, and provides better bond strength and design flexibility, including the 'no-label' look, while maintaining tackiness for sufficient application time without long-term adhesive residue.

Implementation Method 1

the adhesive layer comprises a polyurethane composition which is reversibly changeable from the non-tacky state to the tacky state

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

activatable to become tacky... activation by external energy, such as heat

Methodology Applied
Scientific EffectThermal activation: Heating

Data Source

PatentEP2238211B1A label and a method for attaching the label to an item
Publication Date: 2011.08.03 UPM RAFLATAC OY
  • EP2238211B1 patent drawingFigure 1
  • EP2238211B1 patent drawingFigure 2~3
  • EP2238211B1 patent drawingFigure 4~5

AI summary

The invention relates to a label comprising a substrate having a face side and a rear side, and an adhesive layer arranged on the rear side of the substrate, the adhesive layer being non-tacky but activatable to become tacky. The adhesive layer comprises a polyurethane composition which is reversibly changeable from the non-tacky state to the tacky state. The invention also relates to a method for attaching the label to an item.