ICS59.140
Classification number: Y45
Registration number: 15766-2005
Light Industry Standard of the People's Republic of China
QB/T 2714—2005
Replaces QB/T 3812.9—1999
Physical and mechanical tests
Determination of folding fastness
LeatherPhysical and mechanical tests-Determination of flex resistance(ISO 5402:2002, Leather-Physical and mechanical tests-Determination of flex resistance by flexometer method, MOD)2005-03-19 Issued
National Development and Reform Commission of the People's Republic of China Implemented on 2005-09-01
This standard is a revision of QB/T3812.9-1999 Determination of folding fastness of leather. QB/T2714—2005
This standard is revised and adopts ISO5402:2002 "Leather-Physical and mechanical tests-Determination of flex resistance by flexometer method", which is based on the International Union of Leather Technologists and Chemists (IULTCS) standard IUP20. According to the actual situation in my country, this standard has made the following technical modifications when adopting ISO5402:2002: 1. In the "normative reference documents", the original referenced ISO standards are rewritten as references to relevant standards in my country; 1. For ease of use, the content of 5.1 is split into 5.1 and 5.2, and the subsequent clause numbers are postponed; to prevent incorrect understanding of the standard in use, the reference "note" in 5.1 is deleted and the reference Appendix A (source of the instrument) is cancelled. This standard has also made the following editorial modifications: 1. The foreword of the ISO standard is deleted;
- The term "this international standard" is changed to "this standard"; 2. The decimal point ".\" is used instead of the comma ",\" as a decimal point; 3. The order of the text in 6.6 is adjusted for ease of use. Compared with QB/T3812.9-1999, the main changes of this standard are as follows: "- Added 2 "Normative reference documents", 5 "Sampling and specimen preparation", 7 "Test report" content: - Added the test of "wet specimen"; - Detailed the requirements in "procedure".
This standard is proposed by China Light Industry Federation. This standard is under the jurisdiction of the National Leather Industry Standardization Technical Committee (SAC/TC252), and the drafting unit of this standard is China Leather and Footwear Industry Research Institute. The main drafter of this standard is Zhao Liguo.
This standard was first issued in October 1984 as the original national standard GB4689.9-1984, and was converted into the light industry standard QB/T3812.9-1999 in April 1999. This is the first time Revision. This standard replaces the light industry standard QB/T3812.9-1999 "Determination of folding fastness of leather" issued by the former State Bureau of Light Industry from the date of implementation.
1 Scope
Determination of folding fastness of leather physical and mechanical tests This standard specifies the method for determining the folding fastness of dry or wet leather and leather coating. This standard applies to all types of leather with a thickness of less than 3.0mm. 2 Normative referenced documents
QB/T2714-2005
The clauses in the following documents become clauses of this standard through reference in this standard. For any referenced document with an H date, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, all parties that have reached an agreement based on this standard are encouraged to promote The parties shall study whether the latest versions of these parts can be used. For any undated referenced documents, the latest versions shall apply to this standard. GB/T6682-1992 Specifications and test methods for water for analytical laboratories QB/T2706-2005 Sampling locations for chemical, physical, mechanical and color fastness tests on leather (ISO2418:2002, MOD) QB/T2707-2005 Preparation and adjustment of specimens for physical and mechanical tests on leather (ISO2419:2002, MOD) 3 Processing
The upper test surface of the specimen is folded inwards and placed in a movable fire fixture, and the lower test surface is folded outwards and clamped in a fixed fixture. The upper moving fixture drives the specimen to move, thereby checking for defects in the specimen. 4 Device
4.1 Folding test machine
The folding test machine shall include the components specified in 4.1.1~~4.1.3. 4.1.1 The upper fixture is composed of a pair of flat metal plates rotating around the axis (see Figure 1). One of the metal plates is a trapezoid composed of ABCD, with the corner D being a fillet with a radius of 2mm, and the side EF supporting and clamping the folded specimen. The shape of the other metal plate is EGHCF. The loosening screw K connects the two metal plates together and prevents the specimen from moving beyond the vertical line C from the initial position to the AB direction. There is an adjustment device on the AB side approximately in the middle of the AB line to ensure that the effective action point of the upper fixture is at point F. The upper fixture is driven by a motor and reciprocates with the horizontal axis J as the axis. The downward movement angle is (22.5±0.5) and the movement rate is (100±5) times/min. 4.1.2 The lower fixture is composed of a pair of flat metal plates, fixed below the upper fixture, in the same plane as the upper fixture, to fix the specimen. When the EF side of the upper fixture is horizontal, the distance between the upper side of the lower fixture and the EF side of the upper fixture is (25.0 ± 0.5) mm. 4.1.3 Counter, indicating the number of movements.
4.2 Die cutter
Conforms to the provisions of QB/T2707-2005, the inner wall size is: rectangular (70±1) mm×(45±1) mm. 4.3 Magnifying glass
Can magnify 4 to 6 times.
4.4 Dryer
Or other containers that can be vacuumed.
4.5 Vacuum pump
Can reduce the vacuum degree in the dryer to less than 4kPa. 4.6 Distilled water or deionized water
Conforms to the provisions of grade 3 water in GB/T6682-1992. QB/T2714—2005
4.7 Glass plate
Minimum diameter 100mm, minimum depth 25m
5 Sampling and sample preparation
5.1 Sampling
Perform according to the provisions of QB/T2706-2005.
5.2 Sample preparation
All dimensions ±0.5mm
Perform according to the provisions of QB/T2714—2005. Use a die cutter (4.2) to cut 6 samples from the grain surface for dry testing (or 6 samples for wet testing according to QB/T2707—
test), with the long sides of 3 samples parallel to the ridge line and the long sides of 3 samples perpendicular to the ridge line. 5.3 Air conditioning of dry samples
Dry samples shall be carried out according to the provisions of QB/T2707-2005. 5.4
Preparation of wet test specimens
Place the specimen in a glass dish (4.7)
Add sufficient distilled or deionized water to a minimum depth of 10 mm, place the dish in a desiccator, evacuate the desiccator and maintain the vacuum below 4 kPa for 2 min, then release. Repeat the evacuation and release process twice, remove the specimen, remove the excess water with absorbent paper, and immediately proceed with the wet test. Note: The upper clamp cannot
hold a thick specimen. In this case, the thickness of one end of the specimen can be thinned to 1.5 mm and this end can be inserted into the upper clamp. Leather that is too hard cannot be tested using this method. 6 Procedure
Open the upper and lower clamps (4.1.1 and 4.1.2) so that the space in the clamps is at least twice the thickness of the specimen. 6.1
6.2 Start the motor and make the EF side of the upper clamp (4.1.1) parallel to the upper side of the lower clamp (see Figure 2). 2
QB/T2714-2005
6.3 Fold the test surface of the sample inwards so that the two long sides are together, clamp the folded sample [see Figure 2a), and make the folded side close to the tightening screw of the upper clamp.
Following the lower side of the upper clamp,
6.4 Wrap the two unclamped corners of the sample outwards and downwards [see Figure 26)] so that the two surfaces of the sample are in contact, fix the white end of the sample in the lower clamp [see Figure 2)], and stretch it vertically. The force used should not exceed the force required to just tighten the leather. 6.5 Select the required number of disassembly resistance tests from the following times: Normal test: 500, 1000, 5000, 10000 20000, 25000, 50000, 100000, 150000, 200000, 250000 Wet test: 500, 1000, 5000, 10000, 20000 25000, 50000. For wet test, remove the wet specimen from the test machine every 25000 times, check the water seepage, and re-wet it (5.4), and then put it back into the test machine to continue the test.
Note: The specimen cannot be tested for folding resistance when it is over-expanded. If it does not fold under this condition, the test report should record: a) Specimen in the upper clamp
b) Specimen after folding
Figure 2 Installation of specimen
Completely installed test section
6.6 Stop the testing machine, remove the specimen, fold the specimen in the opposite direction along the longitudinal axis, and examine it with the naked eye and a magnifying glass (4.3) under good light, recording any damage to the bent part and ignoring the part clamped by the clamp. The damage should include the following:
Changes in the color of the coating when there is no damage: cracks in the coating, and the tendency of the cracks to extend into one or more layers of the coating; if possible, the number of cracks should be recorded; abnormal changes in the adhesion of the leather coating:
Abnormal changes in the adhesion between two coatings: powder or flakes in the coating
Cracks in the coating
Color comparison of powder or flakes
If it is necessary to determine the looseness of the leather structure, the flexure can be cut. Note: Since cutting the specimen destroys the specimen and makes subsequent tests impossible, it can be cut after all the last tests are completed. 6.7 If the specimen needs to be removed for observation during the test, the position where the specimen is clamped should be appropriately marked to ensure that the specimen can be fixed in the original position when it is put back
bzxZ.net6.8 Restart the tester and continue the test for the required number of times, repeat the inspection in 6.6. 6.9 If it is necessary to continue the test for another number of times, repeat steps 6.7 and 6.8. Note: The choice of the actual number of revolutions depends on the specified requirements, the final use of the skin segment and the expected performance. 3
QB/T 2714 —2005
Test report
The test report should contain the following contents:
This standard number;
Sample name, number, type:
Detailed information of the sample, sampling discrepancies with QB/T2706-2005; test conditions (standard air: 20℃/65% or 23/50%); test method (dry state, wet state);
Number of folding endurance, condition of the specimen with the most serious damage: differences between actual operation and this standard.
Light Industry Standard of the People's Republic of China
Physical and mechanical tests
Determination of folding fastness
QB/T 2714-2005
Published by China Light Industry Press, version H
Address: No. 6 East Chang'an Avenue, Beijing
Postal code: 100740
Issuing phone number: (010)65241695
Website: http://chlip.com.cnEmail:
[email protected]Editing and Publishing Committee of Light Industry Standardization, editing address: No. 12 Guanghua Road, Chaoyang District, Beijing
Postal code: 100020
Tel: (010)65811585
All rights reserved, infringements will be investigated
Book number: 155019-2762
Price: 10.00 yuan
Print run: 1-200 copies
00 /80
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.