Layered Heating Element Composition for Stable Heat Output

Solution Overview

Problem

Conventional heating elements with exothermic compositions face issues of unusual heat generation due to excessive or uneven distribution of the exothermic composition during production, leading to instability in heat output and quality.

Innovation Solution

A heating element comprising an exothermic layer with an oxidizable metal, a water absorption agent, and water, layered with a water-retention layer having a water absorption sheet, where the mass ratios of the water absorption agent and water are optimized to prevent anomalous heat generation, ensuring stable exothermic characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the exothermic composition is charged with an excessive quantity or unevenly distributed during production, then the heat output may increase, but unusual heat generation and instability in heat output occur

Engineering Contradiction:

Improveheat outputVSAvoidheat generation stability

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The heating element is divided into two distinct layers: an exothermic layer containing the oxidizable metal and a water-retention layer containing the water absorption sheet. This segmentation separates the heat generation function from the water supply function, allowing the exothermic reaction to proceed at a controlled rate while the water-retention layer buffers against variations in exothermic composition distribution, thereby preventing unusual heat generation and stabilizing heat output.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent specifies optimal mass ratio ranges for the water absorption agent (0.3 to 20 parts by mass for 100 parts by mass of oxidizable metal) and water content (0.8 to 13 mass ratio of water/water absorption agent in exothermic layer, 10 to 45 mass% water content in water-retention layer). By controlling these parameters within specific ranges, the system maintains stable heat generation even when exothermic composition distribution varies during production.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the water absorption agent content is increased to control water distribution, then heat generation stability improves, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improveheat generation stabilityVSAvoidlayered structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The heating element is divided into two distinct layers: an exothermic layer containing the oxidizable metal and a water-retention layer containing the water absorption sheet. This segmentation separates the heat generation function from the water supply function, allowing the exothermic reaction to proceed at a controlled rate while the water-retention layer buffers against variations in exothermic composition distribution, thereby preventing unusual heat generation and stabilizing heat output.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent specifies optimal mass ratio ranges for the water absorption agent (0.3 to 20 parts by mass for 100 parts by mass of oxidizable metal) and water content (0.8 to 13 mass ratio of water/water absorption agent in exothermic layer, 10 to 45 mass% water content in water-retention layer). By controlling these parameters within specific ranges, the system maintains stable heat generation even when exothermic composition distribution varies during production.

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

The layered structure with optimized water content in both layers stabilizes heat generation, preventing excessive temperature elevation and maintaining consistent exothermic performance even with variations in composition distribution, thus enhancing production stability and heat output.

Implementation Method 1

an exothermic layer containing an oxidizable metal, a water absorption agent and water

Methodology Applied

Scientific EffectWater absorption: Absorption (physical)

Implementation Method 2

a water-retention layer having a water absorption sheet

Methodology Applied

Scientific EffectWater retention: Absorption (physical)

Implementation Method 3

exothermic compositions constituting oxidizable metals, such as iron powder and the like, carbon components, and water, which produce heat by an oxidation reaction of an oxidizable metal

Methodology Applied

Scientific EffectOxidation reaction: Oxidation

Implementation Method 4

produce heat by an oxidation reaction of an oxidizable metal

Methodology Applied

Scientific EffectExothermic reaction: Exothermic Reaction

Data Source

PatentEP2796118B1Heating element and heating implement

Publication Date: 2019.01.23 KAO CORP

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AI summary

A heating element (10) comprises an exothermic layer (11) containing an oxidizable metal, a water absorption agent and water and a water-retention layer (12) having a water absorption sheet (102), the exothermic layer (11) and the water-retention layer (12)are in layers, in which the mass ratio of the content of the water absorption agent is from 0.3 to 20 parts by mass for 100 parts by mass of the oxidizable metal, mass ratio of content of water to the content of the water absorption agent in the exothermic layer (11) (water/water absorption agent) is from 0.8 to 13, and the content of water contained in the water-retention layer (12) is from 10 to 45 mass% of the maximum water absorption of said water-retention layer (12).