Thermosensitive Label with Segmented Volatile Dye Layers

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Solution Overview

Problem

Current thermosensitive labels for monitoring heat exposure in sensitive articles, such as vaccines and perishable goods, are either costly to store and transport due to temperature sensitivity or lack accuracy in indicating thermal stability, as they are not tailored to individual vaccine thermal stability and require complex synthesis and storage processes.

Innovation Solution

A thermosensitive label comprising two laminated portions: a thermosensitive function layer with a volatile dye and an adsorption-indication function layer, which are physically independent before use, allowing storage at room temperature and accurate heat history monitoring through color change upon heat exposure, with the volatile dye volatilizing and adsorbing, indicating the extent of heat exposure through color depth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a thermosensitive label is designed to immediately change color when temperature exceeds a set value (CTI type), then the response speed is improved, but the label becomes sensitive to heat before use requiring costly refrigerated storage and transport

Engineering Contradiction:
Improveresponse speedVSAvoidstorage temperature
Core Design Contradiction:
SpeedVSTemperature

Solution Approach 1:

The label is divided into two separate functional layers: a thermosensitive function layer containing volatile dye sealed between films, and an adsorption-indication function layer containing adsorption material. These layers are physically independent before use, allowing the thermosensitive layer to be stored at room temperature without premature activation. When activated, the volatile dye vapor diffuses to the adsorption layer to produce the color change indication.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The volatile dye is pre-loaded into the thermosensitive function layer and sealed to prevent premature volatilization. The system is prepared in advance with all components in place, but the actual thermosensitive response is deferred until the sealing is breached or the label is activated for use, enabling room temperature storage during distribution.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If a thermosensitive label uses complex synthesis and multiple functional materials to achieve accurate heat history monitoring, then the measurement precision is improved, but the device complexity increases

Engineering Contradiction:
Improveheat history monitoring accuracyVSAvoidlabel structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention extracts the thermosensitive function (volatile dye volatilization) from the indication function (color change) into separate layers. The volatile dye layer contains only the thermosensitive material sealed for stability, while the adsorption layer contains only the indication material. This separation simplifies each component's function while maintaining overall monitoring accuracy through their interaction during activation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The volatile dye vapor acts as an intermediary between the thermosensitive function layer and the adsorption-indication layer. When activated, the vapor diffuses through the isolation layer to reach the adsorption material, mediating the transfer of thermal information from the sealed thermosensitive layer to the indication layer, thereby enabling accurate heat history monitoring through a simple diffusion-based mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If a thermosensitive label is designed to be stable during storage and transport, then the reliability is improved, but the label cannot accurately indicate heat exposure history

Engineering Contradiction:
Improvestorage stabilityVSAvoidheat exposure indication accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The label achieves different functional qualities in different locations: the thermosensitive function layer is designed for stability during storage with the volatile dye sealed between impermeable films, while the adsorption-indication layer is designed for sensitivity to capture heat exposure signals. The isolation layer provides selective permeability, allowing vapor diffusion only under activation conditions. This spatial differentiation of functional qualities enables both storage stability and accurate heat indication.

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 label effectively monitors heat exposure without being sensitive to heat before use, providing accurate and cost-effective monitoring of thermosensitive articles' quality state, allowing for precise determination of shelf life and storage conditions, while being suitable for mass production and global use.

Implementation Method 1

the volatile dye volatilizes, diffuses through the isolation layer, and then is adsorbed by the adsorption material layer

Methodology Applied
Scientific EffectVolatilization: Evaporation

Implementation Method 2

the volatile dye volatilizes, diffuses through the isolation layer, and then is adsorbed by the adsorption material layer

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 3

the volatile dye volatilizes, diffuses through the isolation layer, and then is adsorbed by the adsorption material layer

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP2937850B1Heat-sensitive label and preparation and use method therefor
Publication Date: 2018.11.14 SUZHOU HUASHI MATERIAL TECH
  • EP2937850B1 patent drawingFigure 1(a)~3
  • EP2937850B1 patent drawingFigure 4~5
  • EP2937850B1 patent drawingFigure 6~8

AI summary

The present invention relates to a thermosensitive label for monitoring the quality state of a thermosensitive article. The present invention also relates to a preparation method of the thermosensitive label and a thermosensitive article using the thermosensitive label. The thermosensitive label according to the present invention comprises two laminated layers which are physically-separated of a thermosensitive function layer and an adsorption-indication function layer. The two laminated layers are stored and transported separately, and combined together in use. Therefore, the thermosensitive label of the present invention can be stored and transported at room temperature, which reduces the cost of use of the thermosensitive label.