Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
GB/T 21655 consists of the following two parts under the general title Textiles — Evaluation of Absorption and Quick-drying:
— Part 1: Method for Combination Tests;
— Part 2: Method for Dynamic Moisture Transfer.
This part is Part 2 of GB/T 21655.
This part is drafted in accordance with the rules given in the GB/T 1.1-2009.
This part replaces GB/T 21655.2-2009 Textiles — Evaluation of Absorption and Quick-drying — Part 2: Method for Moisture Management Tests, and the following technical deviations have been made with respect to the GB/T 21655.2-2009 (the previous edition):
— addition of the description and requirements for the composition and structure of test apparatus (see Clause 5);
— modification of the schematic diagram of test apparatus in Annex A of the original standard and adjusted it to Clause 5;
— modification of the test solution conductivity tolerance to 0.2 mS and addition of the test temperature condition of 25 °C (see 5.2.2);
— modification of the amount of test solution to (0.22 ± 0.01) g (see 8.2, 2009 edition 8.1.2);
— deletion of the “9.1.4 Calculation of composite index for liquid moisture transfer” in the Edition 2009;
— combination of the absorption and quick-drying indexes to uniformly evaluate the absorption and quick-drying;
— deletion of the comprehensive quick-drying index, not separately evaluating perspiration and addition of absorption and perspiration (see Table 2 in Edition 2009);
— addition of the marking of absorption and quick drying (see 10.2);
— modification of the structure schematic diagram of sensor, as well as the probe pitch and contact surface diameter (see A.1; Annex A of Edition 2009);
— modification of the schematic diagram for the principle of data acquisition (see A.2; Annex A.1 of Edition 2009);
— deletion of the demarcation and calibration of test apparatus (see Annex A.5 of Edition 2009).
Attention is drawn to the possibility that some of the elements of this standard may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This part was proposed by the China National Textile and Apparel Council.
This standard is under the jurisdiction of National Technical Committee on Textiles of Standardization Administration of China (SAC/TC 209).
The previous edition of this part is as follows:
— GB/T 21655.2-2009.
Textiles — Evaluation of Absorption and Quick-drying — Part 2: Method for Moisture Management Tests
1 Scope
This part of GB/T 21655 specifies the test method and evaluation indexes for determination, by using the method for moisture management tests, of absorption and quick-drying, as well as absorption and perspiration of textiles.
This part is applicable to various textile products.
2 Normative References
The following referenced documents are indispensable for the application 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 6529 Textiles — Standard Atmospheres for Conditioning and Testing
GB/T 6682 Water for Analytical Laboratory Use — Specification and Test Methods
GB/T 8629-2017 Textiles — Domestic Washing and Drying Procedures for Textile Testing
3 Terms and Definitions
For the purposes of this document, the following terms and definitions apply.
3.1
wetting time
T
time from the liquid comes into contact with the surface of textile to the time it takes for the textile to begin absorbing moisture. It is expressed as the time when the first occurrence of the slope is greater than or equal to tan15° on the relationship curve between moisture content and time
3.2
absorption speed
A
increase rate of moisture content per unit time of textile. The average value of the slope of moisture content change curve during the test time.
3.3
maximum wetting radius
R
the maximum radius of wetting area from textile begins to wet to the end of specified period of time. The maximum radius of wetting area on the moisture content curve from the slope of curve firstly appears greater than or equal to tan15° to the maximum radius of the wetting area to the end of the test time
3.4
spreading speed
S
cumulative transfer speed of liquid moisture in the direction of radius when the wetting textile surface spreading to the maximum wetting radius
3.5
accumulative one-way transport capacity
O
ability of liquid moisture to pass from the wetting textile surface to the permeable surface. It is expressed as the ratio of the difference between the moisture absorption on both sides of textile to the test time
4 Principle
When the textile sample is placed horizontally and the test fluid contacts the immersion surface, liquid moisture will spread along the wetting surface of the textile and transfer from the wetting surface to the permeable surface. At the same time, it diffuses on the permeable surface of the textile. The change process of moisture content is a function of time. After the sample is immersed in the test solution, the state of liquid moisture transfer is measured by a sensor in close contact with the sample, and a series of performance indexes are calculated, so as to evaluate the absorption and quick-drying, as well as absorption and perspiration of the textile.
5 Apparatus and Reagents
5.1 Tester for liquid moisture transfer properties
Tester for liquid moisture transfer properties (see figure 1) mainly includes sensor module, water supply module and data acquisition module, which shall meet the following requirements:
— sensor module: the total mass of upper sensor assembly is (1 000 ± 15) g. For the structure of the sensor, see Annex A, A.1;
— water supply module: capable of dropping (0.22 ± 0.01) g test solution into the textile within (20 ± 1) s;
— data acquisition module: the data acquisition frequency between each test ring shall not less than 10 Hz. The principle is shown in Annex A, A.2.
Foreword II
1 Scope
2 Normative References
3 Terms and Definitions
4 Principle
5 Apparatus and Reagents
6 Standard Atmosphere for Conditioning and Testing
7 Sampling and Test Sample Preparation
8 Test Procedures
9 Result Calculation and Rating
10 Evaluation and Marking
11 Test Report
Annex A (Informative) Sensor Structure and Principle of Data Acquisition
