This standard specifies the method for determining the air permeability of fabrics. This standard is applicable to a variety of textile fabrics, including industrial fabrics, nonwovens and other breathable textile products. GB/T 5453-1997 Determination of air permeability of textile fabrics GB/T5453-1997 Standard download decompression password: www.bzxz.net

ICS59.080.30
National Standard of the People's Republic of China
GB/T5453--1997
eqvIso9237：1995
Textiles
Determination of
thepermeabilityofabricstoair1997-06-09Promulgated
State Administration of Technical Supervision
1997-12-01Implementation
GB/T5453-1997
This standard is a revision of GB5453-85 based on the international standard ISO9237：1995. The revised text is equivalent to the international standard in terms of main technical contents, and at the same time, the contents suitable for existing domestic instruments are added. Compared with the original standard (GB5453--85), this standard has been modified in the following aspects: 1. The air permeability index has been changed from air permeability to air permeability; 2. The requirements for the test area have been added;
3. The pressure drop on both sides of the test specimen was originally specified as 13mmH,0 (127Pa), and is now changed to 50Pa, 100Pa, 200Pa, 500Pa according to the type of fabric;
4. The test results have been added with the calculation of the coefficient of variation CV (%) and the 95% confidence interval. From the date of entry into force, this standard will replace GB5453--85 at the same time. Appendix A and Appendix B of this standard are both informative appendices. This standard was proposed by the Science and Technology Development Department of the China National Textile and Apparel Council. This standard is under the jurisdiction of the Standardization Research Institute of the China National Textile and Apparel Council. The drafting units of this standard are: Shanghai Textile Science Research Institute, National Cotton Textile Quality Supervision and Inspection Center. The main drafters of this standard are: Li Xiaowen, Mai Jiajun, Wang Baojun, Yan Meihua. GB/T5453-1997
ISO Foreword
ISO (International Organization for Standardization) is a worldwide alliance of national standard research institutes (ISO member groups). The formulation of international standards is completed through ISO technical committees. Each member group has the right to attend the technical committee established for a project if it is interested in a certain project. Governmental and non-governmental international organizations associated with ISO can also participate in this work. ISO maintains close contact with the International Electrotechnical Commission (IEC) in terms of electrical standards. The draft international standards adopted by the technical committee are voted on by the member groups. The publication of international standards must be approved by at least 75% of the member groups.
International Standard ISO9237:1995 was formulated by ISO/TC38 Textile Technical Committee. Appendix A and Appendix B of this standard are for reference only. 1 Scope
National Standard of the People's Republic of China
Textiles
Determination of the permeability of fabrics to air
Textiles--Determination of the permeability of fabrics to airGB/T5453-1997
eqvISO9237.1995
Replaces GB5453-85
This standard specifies the method for determining the air permeability of fabrics. This standard is applicable to a variety of textile fabrics, including industrial fabrics, nonwovens and other breathable textile products.
2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB6031-85 Determination of international hardness of vulcanized rubber (30~85IRHD) Conventional test method GB6529-86 Standard atmosphere for humidity conditioning and testing of textiles GB8170-87
3 Definitions
Numerical rounding rules
The following definitions are adopted in this standard.
Air permeabilitywww.bzxz.net
The performance of air passing through fabrics. It is expressed as the rate at which air flows vertically through the specimen under the conditions of specified test area, pressure drop and time. 4 Principle
Under the conditions of specified pressure difference, the air flow rate vertically passing through a given area of ​​the specimen within a certain period of time is measured to calculate the air permeability. The air flow rate can be measured directly or by measuring the air flow rate on both sides of the flow aperture. The pressure difference is converted. 5 Sampling
Sampling shall be carried out according to the procedures specified in the product standard or the agreement of the parties concerned. In the absence of regulations, Appendix B may be used as the basis. 6 Humidification and standard atmosphere for testing
Pre-humidification, humidity adjustment and standard atmosphere for testing shall be in accordance with the provisions of GB6529, and the arbitration inspection shall adopt the secondary standard atmosphere. 7 Instruments
The test instrument shall be calibrated in accordance with the instrument metrological verification regulations. 7.1 Sample round table: It has circular air holes with a test area of ​​5cm2, 20cm2, 50cm2 or 100cm, and the test area error shall not exceed ±0.5%. For air holes with larger test areas, there should be an appropriate sample support net. 7.2 Clamp: It can fix the sample flatly and ensure that the edge of the sample is leak-proof. 7.3 Rubber gasket: used to prevent air leakage, and fits with the fixture (7.2). Approved by the State Bureau of Technical Supervision on June 9, 1997, and implemented on December 1, 1997
GB/T5453-1997
7.4 Pressure gauge or pressure gauge: connected to the test chamber, it can indicate that the pressure drop on both sides of the specimen is 50Pa, 100Pa, 200Pa or 500Pa, with an accuracy of at least 2%.
7.5 Air flow smoothing suction device (fan): it can allow air with standard temperature and humidity to enter the specimen cone, and can cause the air flow passing through the specimen to produce a pressure drop of 50 to 500Pa.
7.6 Flow meter, volume meter or measuring aperture: it can display the flow rate of the air flow, in units of dm/min (L/m in), with an accuracy not exceeding ±2%. Notes
1 As long as the flowmeter and capacity meter can meet the accuracy requirement of ±2%, the measured air flow rate can also be expressed in cm/s or other appropriate units. 2 For instruments using differential pressure flowmeters, check whether the measured air permeability is within 2% of the air permeability calibrated by the calibration plate. 8 Test conditions
Recommended values ​​for test conditions are:
Test area
Clothing fabrics
Industrial fabrics
If the above pressure drop cannot be achieved or is not applicable, 50Pa or 500Pa can be selected after consultation among all parties concerned, and a test area of ​​5cm, 50cm or 100cm2 can also be selected.
If other test areas are used, they should be stated in the report. Note: If the test results are to be compared, the same test area and pressure drop should be used. 9 Steps
9.1 See Appendix A for the method of checking and calibrating the instrument. 9.2 Clamp the sample on the sample cone (7.1). The test point should avoid the edge of the fabric and the wrinkles. When clamping the sample, use sufficient tension to make the sample flat and not deformed. To prevent air leakage, a gasket should be placed on the low-pressure side of the sample (i.e., the side of the sample cone). When there is a difference in the air permeability between the front and back sides of the fabric, the test side should be noted in the report [see 11a) 2]. 9.3 Start the suction fan or other device (7.5) to pass air through the sample, and adjust the flow rate so that the pressure drop gradually approaches the specified value (8.2). After 1 minute or when it reaches stability, record the air flow rate. Note: If a volume meter is used, the volume of about 10 dm3 or more must be measured to achieve the required accuracy. When using a differential pressure flowmeter, an appropriate aperture should be selected and the pressure difference on both sides of the aperture should be recorded. 9.4 Repeat the measurement at least 10 times at different locations on the same sample under the same conditions. 9.5 If there is air leakage at the clamp, measure the air leakage according to A2.2 of Appendix A and subtract the value from the reading. 10 Calculation and Expression of Results
10.1 Calculate the arithmetic mean and coefficient of variation (to the nearest 0.1%) of the measured values. 10.2 Calculate the air permeability R according to formula (1) or formula (2). The result shall be rounded to 2% of the measurement range (full range of measurement range) according to GB8170. qv
￥×167
Where: 4v—average air flow, dm/min (L/min); A—test area, cm\;
(mm/s)
167—conversion factor from dm/minXcm2 to mm/s; 0.167—conversion factor from dm/minXcm2 to m/s. (m/s)
Where formula (2) is mainly used for fabrics with high air permeability such as sparse fabrics and nonwoven fabrics. 10.3 Calculate the 95% confidence interval (R±△) of air permeability according to formula (3). The unit and calculation accuracy are the same as those in 10.2 is the same. 2
（1）
（2）
Where: S—standard deviation;
n---number of tests;
GB/T5453-1997
t——95% confidence interval, confidence value with degree of freedom n-1, the corresponding relationship between t and n is shown in Table 1. Table 1
（3）
For instruments using differential pressure flowmeters, first find out the air permeability from the differential pressure-flow chart, and then calculate its average value, CV value and 95% confidence interval. The calculation accuracy is the same as that required in 10.1 to 10.3. 11
Test report
The test report shall include the following contents:
a) General information
1) The number of this standard, i.e. GB/T5453-1997 and the test date; 2) Sample name, specification, number, and if necessary, the direction of airflow through the fabric; 3) Test area adopted;
4) Pressure drop adopted;
5) Standard atmosphere for humidity adjustment and test;
6) Details of any deviation from this standard.
b) Test results
1) Air permeability R, mm/s or m/s;
2) Coefficient of variation, %;
3) 95% confidence interval, mm/s or m/s.
A1 Inspection and calibration of instruments
GB/T5453-1997
Appendix A
(Appendix of reminder)
Inspection, calibration and test guide of instruments
A1.1 If the instrument is used frequently, it should be inspected once a week to ensure normal use; if the instrument is used occasionally, or after being moved or repaired, it should be inspected before testing. The instrument should be calibrated regularly according to the regulations, and the cycle should not exceed 12 months. A1.2 The pressure gauge should also be inspected regularly.
A1.3 Under a given pressure drop, use a test orifice plate with known air permeability for calibration. It must be ensured that the calibration plate is placed accurately on the sample round table to avoid leakage.
A1.4 The inspection method of some special instruments can be carried out according to the instrument manual, and the test accuracy shall be guaranteed. A2 Test guide
A2.1 Use gaskets to prevent edge leakage. The gasket can be a rubber sheet with a thickness of 2.5mm and a hardness of 65~70IRHD (determined according to GB6031).
A2.2 The edge leakage is measured by covering the sample with a rubber sheet of the same size as the sample. A rubber sheet with a thickness of 2.5mm and a hardness of 65~70IRHD (determined according to GB6031) can be used. A2.3 When clamping the sample, care should be taken not to stretch or wrinkle the fabric. For this purpose, a suitable ring or clamping ring can be used. Appendix B
(Suggestive Appendix)
B1 Batch Sample Selection
Randomly select the number of pieces listed in Table B1 from a shipment or batch of goods as batch samples, and ensure that the batch samples are not damaged or damp. Table B1 Batch Samples
Number of goods shipped or in bulk, piece
B2 Preparation of Laboratory Samples
Minimum number of batch samples, piece
Cut a whole piece of fabric with a length of at least 1m from each piece of the batch sample as a laboratory sample. Note that it should be randomly selected at a position more than 3m away from the end of the fabric, and there should be no wrinkles or obvious spots. 4
National Standard of the People's Republic of China
Determination of Air Permeability of Textile Fabrics
GB/T5453—1997
Published by China Standards Press
No. 16, Sanlihebei Street, Fuxingmenwai, Beijing
Postal Code: 100045
Tel: 68522112
Printed by Qinhuangdao Printing Factory of China Standards Press Xinhua Bookstore North Distributed by Beijing Publishing House, sold by Xinhua Bookstores in all regions. Exclusive copyright. No reproduction allowed.
Format: 880×1230
Printing sheet: 3/4. Number of words: 10,000.
Edition: November 1997
First printing: November 1997
Print run: 1-800
Book number: 155066·1-14273
Price: RMB 8.00
Heading: 322-32
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