Time-Temperature Indicator Volatile Dye Layer Thermal History

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Solution Overview

Problem

Current time-temperature indicators for thermally sensitive articles, such as vaccines and food, lack accuracy in monitoring thermal history and detecting deterioration or failure, as they do not account for the individual thermal stability of each product, leading to inconsistent color change responses.

Innovation Solution

A laminated structure is created with a volatile dye layer and an adsorption material layer sealed on the thermally sensitive article, where the volatile dye absorbs heat, volatilizes, and is absorbed by the adsorption material, causing a color change that correlates with the thermal history and stability of the article, allowing for precise monitoring of quality state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a time-temperature indicator uses a volatile dye layer that changes color through volatilization, then the measurement precision of thermal history monitoring is improved, but the device complexity increases due to the laminated structure with multiple layers

Engineering Contradiction:
Improvethermal history monitoring accuracyVSAvoidlaminated structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The indicator is divided into functionally independent layers: a volatile dye layer for thermal response, an adsorption material layer for vapor capture, and a substrate for support. Each layer performs a specific function, allowing the complex monitoring task to be distributed across simple, specialized components that together achieve high measurement precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The indicator combines multiple materials with different properties: volatile dyes that respond to temperature through sublimation, adsorption materials that capture the volatile vapor, and substrate materials that provide structural support. This composite structure integrates thermal sensitivity, mass transport, and mechanical stability into a single device.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the volatile dye layer is designed to match the thermal stability of each specific product, then the reliability of deterioration detection is improved, but the adaptability decreases due to product-specific customization requirements

Engineering Contradiction:
Improvedeterioration detection accuracyVSAvoidproduct-specific customization
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The volatile dye layer is customized with specific properties (volatility, color change characteristics) matched to the thermal stability of each product type. This local optimization ensures that the indicator's response characteristics align with the deterioration kinetics of the specific article being monitored, thereby improving detection reliability for that product category.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system achieves reliability through precise control of dye parameters (volatility, color change temperature range) that are tailored to match the thermal stability parameters of specific products. By adjusting these physical and chemical parameters, the indicator can be optimized for different product types while maintaining a consistent structural design.

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 solution enables accurate determination of whether a thermally sensitive article has deteriorated or failed by matching the color change response of the dye layer to the thermal history, ensuring the quality state is monitored effectively and safely.

Implementation Method 1

the volatile dye absorbs heat, volatilizes, and then it is absorbed by the adsorption material layer

Methodology Applied
Scientific EffectVolatilization: Evaporation

Implementation Method 2

an adsorption material layer, which irreversibly adsorbs the dye volatilized from the volatile dye layer

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 3

the colour of the volatile dye layer becomes lighter due to the heat absorption volatilization

Methodology Applied
Scientific EffectColor change:

Data Source

PatentEP2728328B1Time-temperature indicator and monitoring method for monitoring quality state of thermally sensitive article
Publication Date: 2018.08.15 SUZHOU HUASHI MATERIAL TECH
  • EP2728328B1 patent drawingFigure 1(a)~2(e)
  • EP2728328B1 patent drawingFigure 2B~4A
  • EP2728328B1 patent drawingFigure 4B~5

AI summary

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