GB/T 42165-2022 English PDF (GBT42165-2022)
GB/T 42165-2022 English PDF (GBT42165-2022)
GB/T 42165-2022: Leather - Tests for colour fastness - Colour fastness to perspiration
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
CCS Y 46
Leather - Tests for colour fastness - Colour fastness to
(ISO 11641:2012, MOD)
ISSUED ON: DECEMBER 30, 2022
IMPLEMENTED ON: JULY 1, 2023
Issued by: State Administration for Market Regulation;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3
1 Scope ... 7
2 Normative references ... 7
3 Terms and definitions ... 8
4 Principles ... 8
5 Instruments and materials ... 9
6 Sampling and sample preparation ... 10
7 Test procedures ... 11
8 Result assessment ... 12
9 Evaluation error ... 13
10 Test report ... 13
Appendix A (Informative) Structural changes of this document compared with ISO 11641:2012 ... 14
References ... 15
Leather - Tests for colour fastness - Colour fastness to
This document describes the test method for the colour fastness to perspiration of leather.
This document is applicable to the test for colour fastness to perspiration of various types of dyed leather.
2 Normative references
The following documents contain the provisions which, through normative reference in this document, constitute the essential provisions of this document. For the dated referenced documents, only the versions with the indicated dates are applicable to this document; for the undated referenced documents, only the latest version (including all the amendments) is applicable to this document.
GB/T 250 Textiles - Tests for colour fastness - Grey scale for assessing change in colour (GB/T 250-2008, ISO 105-A02:1993, IDT)
GB/T 251 Textiles - Tests for colour fastness - Grey scale for assessing staining (GB/T 251-2008, ISO 105-A03:1993, IDT)
GB/T 3922 Textiles - Tests for colour fastness - Colour fastness to perspiration (GB/T 3922-2013, ISO 105-E04:2013, MOD)
GB/T 6151 Textiles - Tests for colour fastness - General principles of testing (GB/T 6151-2016, ISO 105-A01:2010, MOD)
GB/T 6682 Water for analytical laboratory use - Specification and test methods (GB/T 6682-2008, ISO 3696:1987, MOD)
GB/T 7568.1 Textiles - Tests for colour fastness - Specification for wool adjacent fabric (GB/T 7568.1-2002, ISO 105-F01:2001, MOD)
GB/T 7568.2 Textiles - Tests for colour fastness - Standard adjacent fabrics - Part 2: Cotton and viscose
GB/T 7568.3 Textiles - Tests for colour fastness - Standard adjacent fabrics - Part 3: Polyamide (GB/T 7568.3-2008, ISO 105-F03:2001, MOD)
GB/T 7568.4 Textiles - Tests for colour fastness - Specification for polyester adjacent fabric (GB/T 7568.4-2002, ISO 105-F04:2001, MOD)
GB/T 7568.5 Textiles - Tests for colour fastness - Specification for acrylic adjacent fabric (GB/T 7568.5-2002, ISO 105-F05:2001, MOD)
GB/T 7568.6 Textiles - Tests for colour fastness - Specification for silk adjacent fabric (GB/T 7568.6-2002, ISO 105-F06:2000, MOD)
GB/T 7568.7 Textiles - Tests for colour fastness - Standard adjacent fabrics - Part 7: Multifibre (GB/T 7568.7-2008, ISO 105-F10:1989, MOD)
GB/T 7568.8 Textiles - Tests for colour fastness - Standard adjacent fabric - Part 8: Secondary acetate (GB/T 7568.8-2014, ISO 105-F07:2001, MOD)
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 Terms and definitions
There are no terms and definitions that need to be defined in this document. 4 Principles
The leather sample and the adjacent fabric are soaked in artificial perspiration respectively, and then the test surface of the sample and the adjacent fabric are stuck closely to form a composite sample; it is placed in a suitable device and kept at a certain temperature and pressure for the specified time. After the leather sample and the adjacent fabric are dried, the discoloration grade of the leather sample and the staining grade of the adjacent fabric are assessed with the grey scale, respectively. Coated leather can be tested directly or after the coating has been destroyed. NOTE: Usually, the human perspiration just excreted is weakly acidic, but it will change to become weakly alkaline (pH 7.5~8.5) under the action of micro-organisms. Alkaline perspiration has a more obvious effect on leather color than acid perspiration, so this document usually uses alkaline artificial perspiration to simulate actual perspiration for testing.
5.7 Fine-grained abrasive paper, P 180.
5.8 The grey scale used for assessing staining shall comply with the provisions of GB/T 251.
5.9 The grey scale used for assessing discoloration shall comply with the provisions of GB/T 250.
5.10 Die knife shall comply with the provisions of QB/T 2707, and the inner wall is a rectangle with dimensions (100±2) mm × (40±2) mm.
5.11 Vacuum desiccator.
5.12 Vacuum pump that is capable of making the vacuum dryer (5.11) reach a vacuum of 5 kPa (50 mbar) within 4 min.
5.13 pH meter, 0.01 grade.
5.14 Volumetric flask, 1000 mL.
5.15 hydrochloric acid solution, 2 mol/L.
6 Sampling and sample preparation
The sampling shall be carried out according to the provisions of GB/T 39364. If it is not possible to take samples at standard locations (such as leather on shoes and garments), samples can be taken at any location within the usable area. The samples shall be representative and shall be noted in the test report.
6.2 Preparation of samples
The sample is taken by one of the following methods.
a) If the leather is tested without coating or directly with coating, cut a sample of (100±2) mm × (40±2) mm. If it is necessary to test the alkaline perspiration and acid perspiration at the same time, the samples shall be prepared separately. b) If the leather sample needs to be tested after the coating is destroyed, first cut a sample with a size of (120±2) mm × (50±2) mm, and put the coated side down on a 150 mm × 200 mm abrasive paper (the working side of the abrasive paper faces up); place a weight-piece (the bottom surface is flat) of 1 kg evenly on the leather sample, and rub the sample on the abrasive paper back and forth for 100 mm, for a total of 10 times. It is also feasible to rub the sample coating with abrasive paper manually to get the same friction effect. Use a brush to perspiration. However, acid artificial perspiration is often used in other test procedures (such as extraction procedures for the chemical determination of metal content of leather in GB/T 22930.1), so it is included in this document.
7.2 Testing of samples
7.2.1 Soak the leather sample and the adjacent fabric respectively in the artificial perspiration (7.1.1 or 7.1.2) in different containers, and keep it submerged in an appropriate way, such as using a curving glass rod, (if multiple samples need to be tested at the same time, several adjacent fabrics can be immersed in the same container, but the leather samples shall be immersed in different containers). Place the container in a vacuum desiccator (5.11), produce a vacuum of about 5 kPa within 4 min, and keep it for 2 min; then, restore the pressure to a normal level, and repeat this process 2 times; the total time for soaking the sample in artificial perspiration shall not exceed 30 min. Place 1 piece (or 2 pieces) of the adjacent fabric after soaking on a glass plate or acrylic resin plate, and then cover the adjacent fabric with the leather sample, with the side under the test facing down. If both sides of the sample need to be tested, cover the leather sample with another piece (or 2 pieces) of soaked adjacent fabric, and then cover the composite sample with another glass plate or acrylic resin plate.
NOTE: If the sample is tested with a surface coating, directly wet the surface of the sample with artificial perspiration without immersion.
7.2.2 Preheat the stainless-steel frame in an oven at (37±2) °C for at least 1 h, place the composite sample sandwiched between two glass plates or acrylic resin plates in the perspiration tester (5.2), then load a weight-piece and fix the test device so that the pressure on the composite sample remains (12.5±1.0) kPa. To drain excess artificial perspiration from the sample, tilt the tester to each side (approximately 30°) for a few seconds. If several composite samples are tested at the same time, it shall be ensured that each sample is in the middle of two glass plates or acrylic resin plates so that the pressure is evenly applied to the surface of the sample. Remove the weight-piece, place the perspiration tester with the sample horizontally in the oven, and keep it at (37±2) °C for (180±10) min.
7.2.3 After (180±10) min, take the composite sample out of the perspiration tester (5.2), fix it with a needle or a stapler at one corner of the composite sample, and hang it to dry at room temperature. When dry, the sample and the adjacent fabric are in contact only at their fixed points.
8 Result assessment
After the composite sample is dried, under the D65 light source specified in GB/T 6151, the grey scale for assessing staining (5.8) and the grey scale for assessing discoloration (5.9) are used respectively to assess the staining grade of the adjacent fabric and the discoloration grade of the surface of the leather sample.
9 Evaluation error
The difference in assessment results between different assessors shall not exceed half a grade.
10 Test report
The test report shall contain the following contents:
a) the document number;
b) the sample name, serial number, type, and test side;
c) the detailed information on the sample, if the sampling is inconsistent with GB/T 39364;
d) Whether the sample contains a coating, and if so, whether the coating was damaged during the test;
e) the type of artificial perspiration used in the test;
f) test results (staining grades of adjacent fabrics and discoloration grades of leather samples);
g) any special circumstances affecting the test results;
h) any deviation from the methods specified in this document.