Footwear - Test methods for whole shoe - Measurement of thermal and water-vapour resistance
1 Scope
This document describes the test methods for thermal resistance, water-vapour resistance and moisture absorption and breathability property of the whole shoe.
This document is applicable to the determination of the thermal resistance, water-vapour resistance and moisture absorption and breathability property of the whole shoe matched with the test prosthetic foot.
2 Normative references
The following documents contain requirements which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2703 Footwear - Vocabulary
GB/T 6682-2008 Water for analytical laboratory use - Specification and test methods
GB/T 22049 Footwear - Standard atmospheres for conditioning and testing of footwear and components for footwear
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 2703 and the following apply.
3.1
thermal resistance
ability of the whole shoe to prevent heat loss in the inner cavity of the shoe under a certain temperature difference
Note: The greater the thermal resistance, the better the warmth retention of shoes.
3.2
wet-vapour resistance
ability of the whole shoe to prevent water vapour loss in the inner cavity of the shoe under a certain pressure difference
Note: The greater the wet resistance, the worse the breathability property of shoes.
3.3
breathability property
ability of water vapour to penetrate the whole shoe under specified conditions and time
Note: It is usually expressed by the mass of water vapour passing through the whole shoe within a specified time.
3.4
moisture absorption and breathability property
ability of water vapour to be absorbed by shoes and penetrate through the whole shoe under specified conditions and time
Note: It is usually expressed by the sum of water vapour mass absorbed and penetrating through the whole shoe within a specified time.
3.5
coefficient of variation
ratio of standard deviation to average of sample data
Note: It reflects the stability of data, also known as dispersion coefficient. When the coefficient of variation of thermal and water-vapour resistance reaches the set value, it is considered that the temperature gradient and humidity gradient composed of prosthetic foot-whole shoe-environment are in a stable state.
4 Test method A
4.1 Principle of thermal and water-vapour resistance
When the prosthetic foot-whole shoe-environment is in a dynamic process of thermal and humidity exchange, and when the temperature gradient and humidity gradient of the prosthetic foot-shoe-environment are in a stable state, the moisture absorption of the whole shoe is also in a stable state, the water replenishment of the prosthetic foot is equal to the perspiration of the whole shoe, and the calorific value of the prosthetic foot is equal to the heat dissipation of the whole shoe to the environment. The thermal and water-vapour resistance of the whole shoe are calculated according to heating power and sweating amount.
Foreword i Introduction ii 1 Scope 2 Normative references 3 Terms and definitions 4 Test method A 5 Test method B 6 Test report Bibliography
Footwear - Test methods for whole shoe - Measurement of thermal and water-vapour resistance
1 Scope
This document describes the test methods for thermal resistance, water-vapour resistance and moisture absorption and breathability property of the whole shoe.
This document is applicable to the determination of the thermal resistance, water-vapour resistance and moisture absorption and breathability property of the whole shoe matched with the test prosthetic foot.
2 Normative references
The following documents contain requirements which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2703 Footwear - Vocabulary
GB/T 6682-2008 Water for analytical laboratory use - Specification and test methods
GB/T 22049 Footwear - Standard atmospheres for conditioning and testing of footwear and components for footwear
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 2703 and the following apply.
3.1
thermal resistance
ability of the whole shoe to prevent heat loss in the inner cavity of the shoe under a certain temperature difference
Note: The greater the thermal resistance, the better the warmth retention of shoes.
3.2
wet-vapour resistance
ability of the whole shoe to prevent water vapour loss in the inner cavity of the shoe under a certain pressure difference
Note: The greater the wet resistance, the worse the breathability property of shoes.
3.3
breathability property
ability of water vapour to penetrate the whole shoe under specified conditions and time
Note: It is usually expressed by the mass of water vapour passing through the whole shoe within a specified time.
3.4
moisture absorption and breathability property
ability of water vapour to be absorbed by shoes and penetrate through the whole shoe under specified conditions and time
Note: It is usually expressed by the sum of water vapour mass absorbed and penetrating through the whole shoe within a specified time.
3.5
coefficient of variation
ratio of standard deviation to average of sample data
Note: It reflects the stability of data, also known as dispersion coefficient. When the coefficient of variation of thermal and water-vapour resistance reaches the set value, it is considered that the temperature gradient and humidity gradient composed of prosthetic foot-whole shoe-environment are in a stable state.
4 Test method A
4.1 Principle of thermal and water-vapour resistance
When the prosthetic foot-whole shoe-environment is in a dynamic process of thermal and humidity exchange, and when the temperature gradient and humidity gradient of the prosthetic foot-shoe-environment are in a stable state, the moisture absorption of the whole shoe is also in a stable state, the water replenishment of the prosthetic foot is equal to the perspiration of the whole shoe, and the calorific value of the prosthetic foot is equal to the heat dissipation of the whole shoe to the environment. The thermal and water-vapour resistance of the whole shoe are calculated according to heating power and sweating amount.
Contents of GB/T 33393-2023
Foreword i
Introduction ii
1 Scope
2 Normative references
3 Terms and definitions
4 Test method A
5 Test method B
6 Test report
Bibliography
