GB/T 21655.2-2019 English PDF (GBT21655.2-2019)

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GB/T 21655.2-2019: Textiles -- Evaluation of absorption and quick-drying -- Part 2: Method for moisture management tests
GB/T 21655.2-2019
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 59.080.30
W 04
Replacing GB/T 21655.2-2009
Textiles - Evaluation of absorption and quick-drying -
Part 2: Method for moisture management tests
ISSUED ON: JUNE 04, 2019
IMPLEMENTED ON: JANUARY 01, 2020
Issued by: State Administration for Market Regulation;
Standardization Administration of the People's Republic of
China.
Table of Contents
Foreword ... 3 
1 Scope ... 5 
2 Normative references ... 5 
3 Terms and definitions ... 5 
4 Principle ... 6 
5 Devices and reagents ... 6 
6 Standard atmospheres for wet conditioning and test ... 7 
7 Sampling and test preparation ... 7 
8 Test procedures ... 8 
9 Result calculation and rating ... 8 
10 Evaluation and marks ... 10 
11 Test report ... 11 
Annex A (informative) Sensor structure and data acquisition principle ... 12 
Foreword
GB/T 21655 “Textiles - Evaluation of absorption and quick-drying” consists of
two parts:
- Part 1: Method for combination tests;
- Part 2: Method for moisture management tests.
This Part is Part 2 of GB/T 21655.
This Part was drafted in accordance with the rules given in 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”. Compared with
GB/T 21655.2-2009, main technical changes are as follows:
- added description and requirements for composition structure of instrument
(see Clause 5 of this Edition);
- modified instrument structure diagram of original Annex A and adjusted it to
Clause 5;
- modified conductivity tolerance of test standard solution as 0.2mS; added
25°C test temperature conditions (see 5.2.2 of this Edition);
- modified dropped test solution as (0.22±0.01)g (see 8.2 of this Edition, 8.1.2
of Edition 2009);
- deleted calculation of dynamic transport comprehensive index of liquid
water in 9.1.4 of Edition 2009;
- combined moisture-absorption index and quick-drying index; uniformly
accessed moisture-absorption quick-drying;
- deleted comprehensive quick-drying index; not separately accessed
perspiration; added moisture-absorption perspiration (see Table 2 of
Edition 2009);
- added mark of moisture-absorption quick-drying (see 10.2 of this Edition);
- modified sensor structure diagram as well as probe pitch and contact
surface diameter (see A.1 of this Edition, Annex A.5 of Edition 2009);
- modified schematic diagram of data acquisition (see A.2 of this Edition,
Annex A.1 of Edition 2009);
- deleted calibration and alignment of instrument (see Annex A.5 of Edition
Textiles - Evaluation of absorption and quick-drying -
Part 2: Method for moisture management tests
1 Scope
This Part of GB/T 21655 specifies method and evaluation index that use
moisture management method to determine moisture-absorption quick-drying
and moisture-absorption perspiration of textiles.
This Part is applicable to various textiles.
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
The time required from liquid touches fabric surface till fabric starts absorbing
moisture. It is represented by the time when the first slope is greater than or
equal to tan15° on moisture-time relationship curve.
3.2 absorption speed; A
The increase rate of moisture content per unit time of fabric. On moisture
content change curve, it is average slope of moisture content change curve
within testing time.
7.3 Respectively cut 5 pieces of samples before washing and after washing.
Sample size is (90±2) mm×(90±2)mm. For fabric sample, when cutting sample,
it shall be evenly distributed in area above 150mm from edge of cloth. Each
sample shall not be in same vertical (longitudinal) and latitudinal (horizontal)
position; and avoid defects and folds that affect test results. For product, sample
shall be selected from main functional fabric.
7.4 Any unevenness on surface of fabric shall affect test results. When
necessary, it shall use pressing-ironing method to iron sample.
8 Test procedures
8.1 Use clean tweezer to lightly clamp one corner of sample to be tested. Place
sample smoothly between two sensors of the instrument. Usually the surface
that is wearing close to human body is wetting surface. Place it at opposite
direction where test solution is dripping.
8.2 Start instrument. Drip (0.22±0.01)g of test solution to wetting surface of
fabric within specified time. Start recording time and moisture content change.
The time from test solution is dripped till test ends shall be 120s. Data
acquisition frequency is not lower than 10Hz.
8.3 Take sample out. Use clean absorbent paper to absorb excessive residual
liquid from sensor board. Place still for at least 60s. Ensure that there shall be
no residual liquid before testing again.
8.4 Repeat steps of 8.1~8.3 till all samples are tested.
9 Result calculation and rating
9.1 Calculation
9.1.1 Absorption speed A
Respectively calculate average absorption speed of wetting surface AT and
average absorption speed of permeable surface AB according to formula (1).
Round the values off to 0.1.
Where,
A - Average absorption speed, %; it is divided into average absorption speed of
10.2 Marks
Product that is tested according to this Part and has corresponding function in
Table 2 shall be marked with following information in user’s manual:
- reference to this Part, that is, GB/T 21655.2-2019;
- product’s corresponding performance, for example, moisture-absorption
quick-drying or moisture-absorption perspiration.
11 Test report
Test report shall contain following information:
a) reference to this Part and test date;
b) sample description (name, reference number, raw material and main
specifications);
c) procedures and number of times of washing and drying;
d) name and model of test instrument used;
e) average value and rating of calculation result; report standard difference
when necessary;
f) if necessary, report evolution results of moisture-absorption quick-drying
and (or) moisture-absorption perspiration;
g) details of any deviation from this Part and anomalies in test.