GB/T 39371-2020Leather - Physical and mechanical tests - Determination of softness (English PDF)

Foreword

This Standard was drafted in accordance with the rules in GB/T 1.1-2009.

This Standard uses the re-drafting method in the modification and adoption of ISO

17235:2015 Leather - Physical and Mechanical Tests - Determination of Softness.

In comparison with ISO 17235:2015, this Standard has major structural adjustments.

Appendix A provides a table of comparison of Chapter No. between this Standard and

ISO 17235:2015.

In comparison with ISO 17235:2015, the technical differences and the causes for these

differences are as follows:

---In terms of Normative References, this Standard adjusts the technical

differences, so as to adapt to the technical conditions of our country. The

adjustments are intensively reflected in Chapter 2 "Normative References". The

specific adjustments are as follows:

 GB/T 39364, which modifies and adopts International standard, is used to

replace ISO 2418 (see 5.1 and Chapter 8);

 QB/T 2707, which modifies and adopts International standard, is used to

replace ISO 2419 (see 5.2);

---The description of the principle is modified (see Chapter 3);

---The description of the internal spring of the tester is added (see the description

of "D" in Figure 1);

---Titles are added to 4.1 and 4.2 (see 4.1 and 4.2);

---The description of the effective total test force during static measurement in

1 Scope

This Standard specifies the method for the determination of softness of leather.

This Standard is applicable to the determination of softness of various types of flexible

leather, such as: shoe upper leather, furniture leather, clothing leather and luggage

leather, etc.

2 Normative References

The following documents are indispensable to the application of this document. In

terms of references with a specified date, only versions with a specified date are

applicable to this document. In terms of references without a specified date, the latest

version (including all the modifications) is applicable to this document.

GB/T 39364 Leather - Chemical, Physical, Mechanical and Fastness Tests - Sampling

Location (GB/T 39364-2020, ISO 2418:2017, MOD)

QB/T 2707 Leather - Physical and Mechanical Tests - Sample Preparation and

Conditioning (QB/T 2707-2018, ISO 2419:2012, MOD)

3 Principle

Clamp and fix the leather specimen on the base of the tester, then, at an appropriate

speed, lower the cylindrical load stylus directly above the specimen. When it comes

into contact with the specimen, it generates downward pressure, and the amount of

deformation of the specimen represents its softness.

4 Instruments and Materials

7 Result Expression

The softness of specimen is the arithmetic mean value of three determination results,

accurate to 0.1 mm.

8 Test Report

The test report shall include the following contents:

a) Serial No. of this Standard;

b) Detailed information of the sample, and inconsistency with GB/T 39364 in

sampling;

c) Test conditions (standard atmosphere: 20 °C / 65%, 23 °C / 50%, or 27 °C /

65%);

d) Selected circular aperture for the test;

e) Tested part and reading each time;

f) Test results;

g) Any deviation from the method specified in this Standard.

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