GB/T 41424.1-2022 English PDF (GBT41424.1-2022)

This document specifies a test method for the determination of the soiling properties of leather by the tumbling method. This document applies to the determination of the soiling properties of various types of leather.

GB/T 41424.1-2022
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 59.140.30
CCS Y 46
Leather - Determination of soiling - Part 1: Tumbling
method
(ISO 26082-2:2012, Leather - Physical and mechanical test methods for
the determination of soiling - Part 2: Tumbling method, MOD)
ISSUED ON: APRIL 15, 2022
IMPLEMENTED ON: NOVEMBER 01, 2022
Issued by: State Administration for Market Regulation;
Standardization Administration of the People's Republic of China.
Table of Contents
Foreword ... 3
Introduction ... 5
1 Scope ... 6
2 Normative references ... 6
3 Terms and definitions... 7
4 Principle ... 7
5 Reagents and materials ... 7
6 Instruments and equipment ... 7
7 Sampling and specimen preparation ... 10
8 Test steps ... 11
9 Result evaluation ... 13
10 Test report ... 13
Annex A (informative) Changes in the structure of this document compared to ISO 26082-2:2012 ... 15
Annex B (informative) Technical differences between this document and ISO 26082- 2:2012 and their reasons ... 17
Annex C (informative) Composition of synthetic grease ... 19
Leather - Determination of soiling - Part 1: Tumbling
method
1 Scope
This document specifies a test method for the determination of the soiling properties of leather by the tumbling method.
This document applies to the determination of the soiling properties of various types of leather.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. 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 soiling (GB/T 251-2008, ISO 105-A03:1993, IDT)
GB/T 21196.1, Textiles - Determination of the abrasion resistance of fabrics by the Martindale method - Part 1: Martindale abrasion testing apparatus (GB/T 21196.1- 2007, ISO12947-1:1998, MOD)
GB/T 32598, Textiles - Tests for colour fastness - Method for the instrumental assessment of soiling of adjacent fabrics (GB/T 32598-2016, ISO 105-A04:1989, MOD)
GB/T 33729, Textiles - Tests for colour fastness - Cotton rubbing cloth (GB/T 33729- 2017, ISO 105-F09:2009, 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, ISO2419:2012, MOD)
3 Terms and definitions
There are no terms and definitions that need to be defined in this document. 4 Principle
Fix the leather specimen and standard cotton rubbing cloth on both ends of the drum, respectively. Add soiled felt. Rotate to make multiple collisions with the leather specimen. Determine the end point of the soiling test by evaluating the soil of a standard cotton rubbing cloth in the drum.
NOTE: The specimens can be pretreated by natural abrasion and flexural simulation tests during daily use before testing.
5 Reagents and materials
5.1 Synthetic grease: Is used in the preparation of filth. See Annex C for its composition. 5.2 Acetone: Analytically pure.
5.3 Butanone: Analytically pure.
5.4 Petroleum ether (CAS number: 64742-48-9): Analytically pure.
5.5 Graphite milk: An aqueous dispersion with a graphite content of (18±0.5)%, miscible with synthetic grease (5.1).
5.6 White wool felt: Wool content is ≥90%. Density is 0.30g/cm3~0.40g/cm3. Side length is (12.5±0.5) mm. Need to prepare 160 pieces.
5.7 Cotton rubbing cloth: Desized, undyed, in line with GB/T 33729. Cut into a circle with a diameter of (96±1) mm. At least six pieces are required.
5.8 Gray sample card for evaluating soiling: In line with the provisions of GB/T 251, for white leather.
5.9 Gray sample card for assessing discoloration: In line with the provisions of GB/T 250 and is used for leather of other colors.
5.10 Sandpaper: 180 mesh (P180) or higher, if necessary (see 7.4).
6 Instruments and equipment
6.1 Drum soiling device (see Figure 1): The rotation speed is (24±2) r/min. Change the a diameter of (96±1) mm and a rectangle with a size of about 50mm×55mm. 6.9 Soft bristle brush, or other equivalent.
7 Sampling and specimen preparation
7.1 Sampling
Carry out sampling according to the provisions of GB/T 39364, or 50mm away from the edge of the sample. If the grain of the sample contains patterns, samples shall be taken at a representative grain pattern. Record sampling in detail in the test report. 7.2 Specimen preparation
Cut out 4 circular specimens with a diameter of (96±1) mm from the leather for testing. In addition, cut out 4 rectangular specimens with a size of about 50mm × 55mm, which are used as reference samples in the evaluation of results.
7.3 Specimen conditioning
Condition the specimen (7.2) and standard cotton rubbing cloth (5.7) according to the regulations of QB/T 2707. Tests are carried out in the standard atmosphere used for conditioning.
7.4 Specimen pretreatment
7.4.1 Finished leather
If necessary, the surface of the coated leather shall be pretreated before the test. The natural wear and flexure simulation tests of the specimens during daily use can be carried out as follows:
Install the sandpaper (5.10) and the specimen on the specimen holder and grinding table of the Martindale abrasion tester (6.5), respectively. Rub 100 times under 12kPa pressure. After rubbing, carry out 100,000 dry flexure tests in the folding endurance tester (6.4).
The bottom of the specimen shall not be exposed after the pretreatment. Otherwise, use sandpaper with a higher mesh or reduce the pressure of the abrasion test to re-treat the pretreatment. State it in the test report.
NOTE: If the specimen is pretreated, first cut a circular sample with a diameter of not less than 140mm from the leather. After rubbing treatment, cut it into square specimens with side length of (114±2) mm. After folding, prepare the specimen according to the provisions of 7.2. 7.4.2 Unfinished or lightly finished leather
Unfinished or lightly finished leather (such as aniline, suede) can usually be tested directly under standard conditions. For wear simulation pretreatment, use sandpaper with a higher mesh or conduct a wear test under reduced pressure. It is also possible to perform dry flexure directly in the folding endurance tester (6.4) without the abrasion operation. Record the pretreatment in detail in the test report.
8 Test steps
8.1 Preparation of soiling solution
8.1.1 Weigh (145±0.5) g of synthetic grease (5.1). Put into a 1L beaker. Heat slowly in a water bath until the grease melts.
8.1.2 Add 220mL of acetone (5.2), 220mL of butanone (5.3) and 25.0mL of petroleum ether (5.4) to the beaker in turn. Dilute the grease.
8.1.3 Add (0.90±0.01) mL of graphite milk (5.5) to the diluted oil solution. If the grease solution solidifies, gently stir the solution and place in a water bath and heat slowly until melted. The filth shall be prepared and used immediately. It shall not be stored. NOTE: The above solution is enough to soak 160 felts (5.6). To make more soiled felt, scale up each ingredient to make more soiling solution.
8.2 Preparation of soiled felt
8.2.1 Immerse the felts in batches (20 or 40 pieces per batch) in the soiling solution (8.1) for about 3min~5min. Remove and dry on a sieve. Repeat the operation until all 160 soiled felts are prepared.
8.2.2 Put the soiled felt in the oven (6.2) at (60±2)℃ and dry it for (3±1)h. Remove and cool to room temperature.
8.2.3 Place 160 soiled felts in 1 cylinder of the drum soiling device (6.1). The inside of the cylinder is pre-cleaned with a solvent (such as acetone) and a cleaning cloth. Run the device for at least 16h. Disperse the soil evenly in the felt. Take out the soiled felt. Keep in an airtight plastic container.
NOTE: Soiled felts are stored in airtight plastic containers for a maximum of 3 months or until the soiled felts cannot achieve the desired soiling properties (8.2.6).
8.2.4 Use a colorimeter (6.3) to measure the chromaticity values , , of two standard cotton rubbing cloths (5.7) respectively. Place on both ends of 1 cylinder. The inside of the cylinder is pre-cleaned with a solvent (such as acetone) and a cleaning cloth.
a cleaning cloth to clean the inside of each cylinder.
8.3.2 Install the specimen (the test surface is facing the inside of the cylinder) on one end of the four cylinders. Install a standard cotton rubbing cloth on the other end of the cylinder. Put 40 soiled felts inside each cylinder. Turn on the device after closing the lid. The runtime is tc (8.2.6). Take out the cotton rubbing cloth. Immediately measure the chromaticity values , , of the cotton rubbing cloth. Calculate the color difference value of the cotton rubbing cloth according to formula (1).
8.3.3 If the color difference value of the cotton rubbing cloth reaches the specified requirement (20.0±1.0), the test shall be continued according to the steps of 8.3.4. If the color difference value is less than the specified requirement, put the cotton rubbing cloth back into the cylinder. Take out to measure after continuing to run for 15min. Repeat the operation until the color difference value of the standard cotton rubbing cloth reaches the specified range.
8.3.4 Take out the specimen. Before evaluating the results, use a soft-bristle brush (or other equivalent) to gently remove visible loose debris from the surface of the specimen. 9 Result evaluation
9.1 Evaluation of results for unpretreated specimens
Cut a rectangle (50×55) mm from the center of each soiled specimen. The direction of its long side is the same as that of the reference sample (7.2). Use the reference sample as the reference. Use the grey scale (5.8 or 5.9) to rate the test specimens. 9.2 Evaluation of the results of wearing simulated pretreated specimens For pretreated specimens, the surface of the specimens shall be inspected after the test. Record any visible soiling, its morphology and its severity (e.g., visible soiling from flex cracks) in the report. The specimens are then rated as specified in 9.1. 10 Test report
The test report shall contain the following:
a) Reference to this document;
b) Detailed information of the sample (including color), inconsistence between sampling and GB/T 39364;
c) Test conditions (standard atmosphere: 20°C/65%, 23°C/50% or 27°C/65%);