This standard specifies the determination method of water absorption of leather. This standard is applicable to all kinds of leather. GB/T 4689.21-1996 Determination method of water absorption of leather GB/T4689.21-1996 Standard download decompression password: www.bzxz.net

GB/T 4689.21--1996
This standard is equivalent to ISO2417:1972 "Leather - Determination of water absorption". This standard is completely consistent with ISO2417:1972 in terms of technical requirements and test results, and only differs in format. This standard is proposed by China Light Industry General Association.
This standard is under the jurisdiction of the National Fur Leather Standardization Center. This standard is drafted by the China Leather Industry Research Institute. The main drafter of this standard is Zhao Liguo.
GB/T4689.21-1996
ISO Foreword
ISO (International Organization for Standardization) is a standardization organization composed of standardization organizations (ISO members) from all over the world. The drafting and formulation of international standards must be approved by ISO technical committees. Each member has the right to make comments to the committee to which it belongs on the draft standard issued by the technical committee. International organizations, governmental organizations, and non-governmental organizations that have relations with ISO can participate in the relevant work. Before being officially adopted as an ISO international standard, the ISO technical committee sends the draft international standard adopted to all member organizations for voting and comments.
International Standard ISO2417 was proposed by ISO/TC120 Technical Committee on Leather and adopted by the following member countries in November 1971: Brazil
Czechoslovakia
Hungary,
No member expressed opposition.
Israel
Italy
New Zealand
Portugal
Romania
Spain
Turkey
This international standard adopts the IUF/7 standard of the International Union of Leather Technologists and Chemists. 9
1 Scope
National Standard of the People's Republic of China
Determination of absorption of water
LeatherDetermination of absorption of water This standard specifies the determination method of water absorption of leather. This standard is applicable to all kinds of leather.
2 Referenced standards
GB/T4689.21—1996
eqv ISO 2417:1972
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard was published, the versions shown were 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. GB4689.2—84 Leather—Air conditioning of test pieces for physical property tests GB4689.10—84 Determination of apparent density of leather 3 Principle
A test sample of a certain specification is soaked in a certain amount of distilled water at a specified temperature. After a specified time, the water absorption of the sample is measured. 4 Apparatus
4.1 Cooper blood: Made of glass (see Figure 1), a glass rod or a nickel wire or stainless steel wire with a diameter of about 1 mm is fixed on the rubber stopper C so that the sample can maintain a certain distance from C at the bottom of B. C
4.2 Steel die knife: The inner wall is a right cylinder with a diameter of 70mm. The inner and outer surfaces of the knife edge form an angle of about 20°. The height of the wedge formed by this angle should be greater than the thickness of the leather.
4.3 Balance: Accuracy 0.01g. wwW.bzxz.Net
Approved by the State Administration of Technical Supervision on December 17, 1996, and implemented on May 1, 1997
5 Samples
GB/T4689.21—1996
Cut the sample with the die knife, with the grain facing up, and then perform air conditioning according to GB4689.2. 6 Test conditions
All operations must be carried out in the standard air specified in GB-4689.2 7 Test steps
7.1 Place the Cooper dish with part A at the bottom and part B at the top, add about 75mL of (20±2)C distilled water, and make the water surface between the scale of 0 and 1.
7.2 Weigh the weight of the sample, or measure the volume of the sample according to GB4689.10. Read the scale of distilled water, put the sample into part B of Cooper III, and let the distilled water flow slowly into part B to completely submerge the sample. Cover the mouth with rubber stopper C to prevent evaporation and loss of water. 7.3 After the sample is soaked for the specified time, lift part B and let the water flow into part A. 1 minute after all the water flows out, read the scale of water and calculate the water absorption.
7.4 If continuous measurement of water absorption is required, quickly level the Cooper's blood, allow the water to flow back to part B, and continue to immerse the sample. The measurement can be carried out according to the following prescribed time:
1/4h, 1/2h, 1h, 2h, 24h.
7.5 Repeat the operations of 7.3 and 7.4 at the prescribed time. 8 Operation precautions
8.1 To make the cut of the sample smooth, it is best to put a piece of thick paper between the sample and the cutting table when cutting the sample. 8.2 The sample that has been measured for apparent density according to GB4689.10 can continue to measure water absorption. 8.3 Before each test, the Cooper's blood must be cleaned, rinsed with distilled water and the inner wall must be kept moist. 8.4 The time for each water control cannot be regarded as the time of the previous immersion, but can be used as the time for subsequent tests. 9 Result Expression
9.1 Water absorption Q: expressed as milliliters of water absorbed by every 100g leather sample, calculated as formula (1): Q = 100×#
9.2 Water absorption P: expressed as milliliters of water absorbed by every 100mL volume of leather sample, calculated as formula (2): P = 100 ×
Where: Q-
-water absorption, mL/g;
water absorption, mL/mL;
-weight of sample, g;
Vi--milliliters of water absorbed by sample, mL; Vz--volume of sample, mL.
Calculation results should be kept to integers.
10 Test report content
a) This standard number;
b) Sample name, number, type, manufacturer (or trademark), production date; c) Test results (test time, each test value, final result); (1
· (2)
d) Abnormal phenomena in the test;
GB/T 4689.211996
e) Differences between the actual measurement method and this standard; f) Test personnel, date.
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