This standard specifies the Gurley method for determining the air permeability of paper and paperboard. This standard is only applicable to paper and paperboard with an air permeability between (0.1 and 100) μm (Pa·s). It is not applicable to materials with rough surfaces, such as crepe paper and corrugated paper, because these cannot be clamped firmly and will inevitably leak air. GB/T 5402-2003 Determination of air permeability of paper and paperboard (medium range) Gurley method GB/T5402-2003 Standard download decompression password: www.bzxz.net

ICS85.060
National Standard of the People's Republic of China
GB/T 5402—2003
Replaces GB/T5402—1985
Paper and board
Determination of air permeability (medium range)
Gurley method
Paper and board-Determination of air peremeance(medium range)-Gurley method
EISO 5636-5:1986,Paper and board—Determination of air peremeance(medium range)Part 5:Gurley method,MOD12003-10-20issued
People's Republic of China
General Administration of Quality Supervision, Inspection and Quarantine
2004-06-01implemented
GB/T 5402-2003
This standard is modified to adopt ISO5636-5:1.986 Paper and paperboard-Determination of air permeability (medium range)-Part 5: Gurley method.
The main technical differences and reasons and structural comparison between this standard and [ISO5636-5:1986] are listed in Appendix C and Appendix D respectively: This standard replaces GB/T5402-1985 "Determination of oxygen permeability of paper and paperboard (Gurley method)". Compared with GB5402-1985, the main changes of this standard are as follows: - The standard format is modified in accordance with GB/T 1.7-2000 "Guidelines for standardization Part 1: Structure and writing rules of standards"
- According to the original content of ISO5636-5:1986, the introduction of early instruments is added; the scale value of the burette in Appendix B is revised to 0.2 mL/grid. Appendix B of this standard is a normative appendix, and Appendix A, Appendix C, and Appendix D are all informative appendices: This standard is proposed by the China Paper Industry Federation. This standard is proposed by the National Paper Industry Standardization Technical Committee. The responsible drafting unit of this standard is: Chongqing Paper Industry Research and Design Institute, and the participating drafting units are: Chongqing Station of National Light Industry Paper Quality Supervision and Inspection, Chongqing Paper Metrology Station,
The main drafters of this standard are: Xie Qing, Wang Jinggang, Zhou Bo. The previous versions of the standards replaced by this standard are: GB/T5402~1985. This standard is interpreted by the National Paper Industry Standardization Technical Committee. 1 Scope
Paper and paperboard, determination of air permeability (medium range) Gurley method
This standard specifies the Gurley method for measuring the air permeability of paper and paperboard. GB/T5402—2003
This standard is only applicable to paper and paperboard with air permeability between (0,1~100)μim/(Pas). It is not applicable to materials with rough surfaces, such as ribbed paper and tile-based paper, because these papers cannot be firmly clamped and thus inevitably leak air. 2 Normative references
The following clauses become clauses of this standard through reference in this standard. All dated references and their subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties to an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For all undated references, the latest versions shall apply to this standard. GB/T450 Paper and paperboard specimen collection (GB/T450-2002, eqVISO186:1994) GB/T10739 Standard atmospheric conditions for handling and testing paper, paperboard and pulp specimens (GB/T10739-2002, cqVISO187:1990)
3 Terms and definitions
The following terms and definitions apply to this standard. 3.1
Air permeability
The average air flow rate through a unit area per unit time under unit pressure difference under specified conditions, expressed in micrometers per Pascal second [1 mL/(m - Pa s)--1 μm/(Fa * s). 4 Principle
The air in the cylinder is compressed by its own weight of a vertically erected cylinder floating on a liquid, so that the compressed air contacts the sample. As the air passes through the sample, the cylinder will fall steadily. The time required for a certain volume of air to pass through the sample is measured, and the air permeability is calculated accordingly. 5 Instrument
5.1 Erlier Air Permeability Tester
The schematic diagram of this instrument is shown in Figure A.1. It consists of an outer cylinder and an inner cylinder. The outer cylinder contains a certain amount of sealing liquid, and the inner cylinder can slide freely in the outer cylinder. The air pressure formed by the gravity of the inner cylinder is applied to the sample clamped between the clamps with a hole diameter of (28.6 + 0.1) mm: the sample clamp of the single-stage instrument is at the top of the cylinder, and the sample clamp of the new instrument is on the base. The latter is the most suitable choice [see Figure A, 1a]. On the side of the clamp with air pressure, a rubber pad is installed to prevent air from entering between the paper surface and the clamp.
The liner is made of thin, elastic, oil-resistant and oxidation-resistant material and has a smooth and flat surface. The thickness of the liner is (0.7～1.0)Tnt, the hardness is (50～60)IRHD (International Rubber Hardness Scale), the inner diameter is (28.6±0.1)mm (area is 6.42cm), and the outer diameter is (34.9=0.1)mml. The hole of the liner should be accurately aligned with the hole of the splint. During use, in order to make the two holes of the liner and the splint aligned and protect the liner, the liner should be pasted in the positioning groove of the splint. The circular groove should be concentric with the splint hole opposite to it, and its inner diameter is (28.41±0.04)mm. The groove depth is (0.45±0.05)mm, and the outer diameter of the groove is (35.2±0.1)mm. GB/T5402—2003wwW.bzxz.Net
Note: The inner diameter of some instrument grooves is 28.65 Im, so that the liner is slightly tightened. The outer cylinder height of the instrument is 254mm, and the inner diameter is 82.6mm. Three or four metal bars are arranged vertically at equal distances on the inner wall of the cylinder. The length of the metal bars is between (190~~245.5)mm. The cross section of the bars is either a square with a side length of 2.4mm or a circle with a diameter of 2.4mm. The metal bars serve as guides for the inner cylinder to move up and down. The inner cylinder height is 254mm, the outer diameter is 76.2mm, the inner diameter is 74.1mm, and the mass is (567±0.5)g.
The volume mentioned above is the theoretical volume of the instrument. The actual volume contains a slight increase because the inner cylinder wall replaces part of the liquid during the test. In actual operation, the errors caused by these normal reasons are common to the instrument and can therefore be ignored. The volume of the inner cylinder of the instrument can be calibrated according to the method in Appendix B.
5.2 Sealing
The density of the sealing liquid at 38℃ is 860g/m2, the dynamic viscosity is (10~13)mm/s[equivalent to (60~70)sSayboltl, and the flash point should not be lower than 135℃.
5.3 Auxiliary equipment
Cash meter or electronic meter, the minimum scale value or resolution is 0.2$. 6 Sampling
Sampling shall be carried out in accordance with the provisions of GB/T450
7 Temperature and humidity treatment
The temperature and humidity treatment shall be carried out in accordance with the provisions of GR/T[0739] 8 Preparation of test samples
Cut one test sample from each of the 10 selected paper samples. If the clamping plate of the instrument is on the inner cylindrical part, the sample size should be 50mm×120mm; if the clamping plate of the instrument is on the base, the sample size should be 50 mmx50 mm
9 Test steps
9. 1 Calibration
Put a flat, hard, dense, non-permeable metal or plastic sheet between the two orifice plates to check the sealing of the instrument. Check according to 9.3. After 5 hours of measurement, the air leakage should not exceed 50mL. 9.2 Environmental
The test should be carried out under the same atmospheric conditions as the temperature display treatment. 9.3. Adjust the instrument to a horizontal level so that the two cylinders are in a straight position. Inject oil into the outer cylinder to a depth of 120 mm, that is, to the ring mark on the inner cylinder (this step can be omitted in subsequent tests if the oil level remains unchanged): For instruments with the clamp at the base, first raise the inner cylinder so that its edge is on the support device of the outer cylinder. Clamp the sample between the clamps: Then remove the support device and let the inner cylinder descend until it can float. For instruments with the clamp at the top, lift the inner cylinder with one hand and hold the sample with the other hand, then release the inner cylinder and let it float in the oil. Another method is to move the inner cylinder together and then adjust the sample so that the inner cylinder slowly descends in the outer cylinder. Always tighten the knurled nuts alternately to make the pressure on both sides of the clamp equal. If only one nut is tightened and the clamp does not press flatly on the sample, air leakage may occur.
Note 2: Be careful when tightening the nuts alternately to prevent oil from getting on the test tube and reduce the volume of oil that may contaminate the sample. When the inner cylinder moves downward steadily, start timing from the zero scale and measure the time required for the initial two 50mL intervals (i.e., the intervals from 0mL to 100mL) to pass through the edge of the outer cylinder. The measurement accuracy is as follows: 605
> 605 to ≤.180 s
180 s
Accurate to 0.2 S
Accurate to 1s
Accurate to 5 s
GB/T5402—2003
For paper and paperboard with poor air permeability, start timing at the end of the first 50mL; for very loose paper or paper with holes: the time required for a larger volume of air to pass through can be measured. If the cylinder does not move evenly before reaching the zero mark, start timing from the 50 mL mark.
Note: Avoid moving the instrument as this will increase the air flow rate. 9.4 Number of tests
Five specimens should face up and five specimens should face up. 10 Expression of results
10.1 Calculate the air permeability according to formula (1) and express the result as the arithmetic mean of 10 measurements, accurate to two significant figures. P.1.27V
Wu Zhong:
V… Volume of air passing through, in milliliters (mL); t—Time required for air to pass through V mE., in seconds (s); P—Air permeability, in micrometers per Pascal seconds [um/(Pa·s)]. Note 1: Formula (1) is based on an average pressure difference of 1.23 kPa and a test area of ​​6.42 cm2. Note 2: Since P and 1 are nonlinear, the average value of 1 should not be used to calculate the average value of P. 10.2 If a standard deviation is required, it can be calculated and corrected from the number of repeated measurements in micrometers per Pascal seconds according to formula (1). 10.3 If there is a large difference in the air permeability between the front and back sides of the test piece and it is required to report this difference, 10 samples should be measured on each side and the two results should be reported separately. 10.4 If it is necessary to report the air permeability resistance, it should be expressed in seconds using the Gurley air permeability resistance, which is the time measured in 9.3. If the reported result is ≤10 s, it should be accurate to the first decimal place, otherwise it should be accurate to two significant figures. 11 Precision
The deviation of the average value of two samples obtained from the same paper sample and measured by the same operator in the same laboratory should be within 10%.
12 Test report
The test report shall include the following items:
a) the number of this standard;
the date and address of the test,
all the data required for complete identification of the sample: the type number of the instrument used,
the temperature and relative humidity during warm treatment and inspection,
the number of specimens tested,
the test results;
the required standard deviation or coefficient of variation,
any deviation from the prescribed procedures.
GB/T 5402—2003
Appendix A
(Informative Appendix)
Changes in the instrument
A.1 Figure A.1 shows references to two types of instruments, one with a clamp mounted on a floating inner cylindrical element (Figure A, 1a) and the other with a clamp fixed to the base of the instrument (Figure A, 1b), and the dimensions used are from the current prototype of this type. Many early versions of this instrument still exist, the earliest instruments were not equipped with pads. However, it can be assumed that the instruments manufactured since 1945 have been equipped with pads. In these instruments, the dimensions are slightly different, but the differences in the test results are not significant. The inner diameter and groove of the pad also seem to be slightly different, so sometimes the pad needs to be slightly stretched to fix it in the case. However, the effective area of ​​the test has always been the original 6.452cm (1in*). The deviation is within 1%. A 2 Some instruments have internal cylinders with 25 mL as unit scale within the first 100 mL, and also have scales at 400 mL. The scales on some cylinders are made by gluing labels with scales. A.3 Another internal cylinder with a mass of 142 g is used. When measured with this cylinder, the air flow rate can be approximately considered to be 1/4 of the value measured with the 567 g cylinder.
A4 Sometimes, clamps with a measuring aperture of 1.61 cm2 (diameter 14.30 mm) or 0.645 cm (diameter 9.05 mm) are used. The air flow rate measured by them is approximately 1/4 or 1/10 of the normal value. When cylinders and clamps with different speeds are used, it should be stated in the report, because the results can only be converted to the approximate results of the standard instrument. 28.5 2m
e) Early form
Mass 667 onwards
Foreign garden merchants
Air vent
b) Most new forms
Appendix B
(Normative Appendix)
Volume calibration
GB/T5402—2003
B.1 Check air leakage according to 9.1. If the air leakage in 5 hours exceeds 50 mL, replace the hard surface material with soft rubber and repeat the above inspection. If no leakage is found at the splint, find the leakage point and seal the leakage point with fluoroprene rubber or other adhesive. B.2 Figure B.1 shows the calibration device for the internal test tube volume. Use a special connecting plate (see Figure B2) to connect the Gurley instrument to the 100mL titration substitute through two three-way switches A and B. The scale of the burette is 0.2mL/grid. A three-way switch D is added between the vacuum and switch A. All connections should use pressure-resistant rubber tubes. B.3 When the vacuum tube is evacuated, A1, D, and C should be connected to allow water to enter the burette and make the water level reach the 35 mL scale line, and then D1 should be released to restore the atmospheric pressure. Open B, lift the inner cylinder above the sealing surface, and then close B1. Connect A and B2 to allow water to flow out of the burette and make the zero scale of the inner cylinder just on the reference point of the outer cylinder. Let the instrument stand for 15 minutes to check for air leakage. If the inner cylinder moves, check all interfaces for leaks. B.4 Adjust the zero scale line to align it with the reference point and record the burette indication, which should be accurate to 0.1 mL. Allow water to flow from the burette until the first 50 mL mark on the inner cylinder coincides with the reference point of the outer cylinder, and record the burette reading again, accurate to 0.1 mL. The difference between the two values ​​is the volume of the first 50 mL interval of the Gurley apparatus. B.5 From 0 mL to 350 mL - a measurement should be made for each 50 mL interval, and the average of each three measurements should be calculated. If the deviation of each measurement from the half mean is not within 1.0 mL, the measurement should be repeated. 5.1% should be subtracted from each average to compensate for the volume of fluid displaced by the cylinder wall. If the error is greater than 3%, a calibration table for the inner cylinder should be prepared. Rubber
All are stopcocks:
H—Connection point empty device;
Connection plate:
E----Rubber stopper
100 mL burette:
Water bottle.
Figure B, 1 Instrument calibration
Figure B.2 Connection plate
GB/T 5402—2003
Acknowledgement C
(Informative supplement)
Technical differences between this standard and ISO 5636-5: 1986 and their causes Table C.1 gives a list of the technical differences between this standard and ISO 5636-51986 and their causes. Table C.1 Technical differences between this standard and ISO 5636-5:1986 and their reasons Chapter number of this standard Appendix B Technical differences Change “Purpose and application paradigm” in Chapter 1 of ISO 5636-5:1956 to “Scope”. Change “References” in Chapter 2 of ISO 5636-5:1986 to “Normative references”. Change “Definition” in Chapter 3 of ISO 5636-5:1986 to “Determination and determination”. Add “In the subsequent tests, if the oil level remains unchanged, this step can be omitted”. Remove the formula P=127. Change “Standard deviation or required coefficient of variation” to “required standard deviation or coefficient of variation”.
Emphasis on the consistency with GB/T 1.1:
Emphasis on the consistency with GB/T 1.1.
Emphasis on the consistency with GB/T1.1.
To suit the actual testing process.
Because P12] is consistent with -1-27.
According to the provisions of my country's papermaking product standards and method standards, most inspection reports do not have requirements for standard deviation and coefficient of variation.
Change the second paragraph of Appendix B of ISO5636-5:1956, "The scale of the titration is", because in the standard series of our burette products, the accuracy is 0, 1 mL", to "The scale of the titration tube is 0. 2 ml". The volume level is 0. 2 mL/grid, so this modification is made. Appendix D
(Informative Appendix)
Comparison of the number of chapters and clauses of this standard and ISO5636-5:1986 Table D.1 gives a table of the comparison of the abbreviations of the chapters and clauses of this standard and ISO5636-5:1986.
Chapter and clause numbers of this standard
Appendix C
Comparison of the number of chapters and clauses of this standard and ISO5636-5:1986 GB/T 5402—2003
Corresponding international standard chapter and clause numbers
Note: The number of other clauses of this standard other than this table is the same as that of other clauses and clauses of ISO5636-5:1986 and the contents correspond.
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