GB/T 40910-2021 English PDF (GBT40910-2021)

This document specifies the terms and definitions, test methods, evaluation and identification for water resistance and water vapour permeability of textiles. This document applies to all types of fabrics and their products.

GB/T 40910-2021
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 59.080.30
CCS W 04
Textiles - Evaluation for water resistance and water vapour
permeability
ISSUED ON: OCTOBER 11, 2021
IMPLEMENTED ON: MAY 01, 2022
Issued by: State Administration for Market Regulation;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions ... 4
4 Sampling and sample preparation ... 5
5 Test methods ... 5
6 Evaluation and identification ... 6
7 Test report ... 7
References ... 8
Textiles - Evaluation for water resistance and water vapour
permeability
1 Scope
This document specifies the terms and definitions, test methods, evaluation and identification for water resistance and water vapour permeability of textiles. This document applies to all types of fabrics and their products.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the version corresponding to that date is applicable to this document; for undated references, the latest version (including all amendments) is applicable to this document. GB/T 4744, Textiles - Testing and evaluation for water resistance - Hydrostatic pressure method
GB/T 4745, Textiles - Testing and evaluation for water resistance - Spray test method GB/T 8629-2017, Textiles - Domestic washing and drying procedures for textile testing
GB/T 12704.2-2009, Textiles - Test method for water-vapour transmission of fabrics - Part 2: Water method
3 Terms and definitions
The following terms and definitions are applicable to this document.
3.1
Water resistance and water vapour permeability
The performance of the sample to resist wetting and permeation by water, and to allow water vapour to escape.
Note: The water resistance and water vapour permeability of the sample is generally characterized by hydrostatic pressure, spray rating and water vapour
transmission rate.
3.2
Hydrostatic pressure
The pressure per unit area of a sample when it is permeated by liquid water. 3.3
Spray rating
The degree to which a fabric surface resists wetting by water.
[Source: GB/T 4745-2012, 3.2]
3.4
Water vapour transmission rate
WVT
The mass of water vapour passing through the unit area of the sample vertically within the specified time, under the condition of keeping the specified temperature and humidity on both sides of the sample, in grams per square meter hour [g/(m2·h)] or grams per square meter 24 hours [g /(m2·24h)].
[Source: GB/T 12704.2-2009, 3.1]
4 Sampling and sample preparation
4.1 The method and quantity of sample collection shall be carried out according to the product standard. For fabrics, each full-width fabric of more than 1.5 m cut, during sampling, shall be more than 15 cm from the edge of the fabric, and more than 2 m from the edge shall be avoided; for products, it shall be at least 2 units.
Note: The unit can be pieces, sets, strips, etc.
4.2 Cut representative samples -- which meet the test requirements of hydrostatic pressure, spray rating and water vapour transmission rate -- from the item. The samples shall avoid defects, stains and wrinkles that affect the test results. For products, samples for hydrostatic pressure shall be taken from different fabrics that meet the test requirements; samples for hydrostatic pressure at the seam shall be taken from the seam tape at the flat part.
5 Test methods
5.1 Hydrostatic pressure