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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard is revised from QB/T 2922-2007 Case and Bag—Test Method for Fall Down.
The following main changes have been made with respect to QB/T 2922-2007:
——the requirements of impact device are adjusted;
——the requirements of fixture are added;
——the requirements of sucker noise reduction device are added;
——the requirements of control device are adjusted;
——the requirements of specified load are deleted;
——Annex A is added as a normative annex.
This standard was proposed by the China National Light Industry Council.
This standard is under the jurisdiction of the National Technical Committee on Leather Industry of Standardization Administration of China (SAC/TC 252).
From the implementation date hereof, this standard replaces the former light industry standard QB/T 2922-2007 Case and Bag—Test Method for Fall Down which is simultaneously abolished.
The previous edition of this standard is as follows:
——QB/T 2922-2007.
Case and Bag—Test Method for Shaking Impact
1 Scope
This standard specifies the principle, devices and test method for shaking impact of case and bag.
This standard is applicable to various cases and bags for daily use.
2 Principle
Apply a certain load to case and bag, lift it through handle or shoulder straps (or fully opened trolley) to a fixed stroke and subject it to free fall under the action of gravity (trolley is tested through motion at a constant speed). Then subject it to impact and shaking via a spring absorbing and releasing impact force, so as to inspect the resistance to shaking impact of handle, shoulder straps, trolley and case body (bag body).
3 Devices and Materials
3.1 Shaking impact tester
The shaking impact tester for case and bag shall comprise components given in 3.1.1~3.1.7 and see Annex A for structural diagrams of main components.
3.1.1 Impact device
As shown in Figure A.1 of Annex A, impact device comprises lower sucker, upper damping rubber block, damping spring, lower damping rubber block, impact bar and common fixture (fixture for double shoulder straps).
The total weight of lower sucker, upper damping rubber block, impact bar and common fixture is (8.1±0.2) kg.
The impact device can move up and down, with a one-way stroke of (150±5) mm. The stroke is set against the applied load on impact device of 30kg.
3.1.2 Upper sucker and noise reduction device
As shown in Figure A.2 of Annex A, an adjustable hydro-pneumatic noise reduction device is arranged at the upper sucker, and the elastic force for the bottom of noise reduction device (as shown in Figure A.1, 10 of Annex A) compressed to the same plane as the bottom of upper sucker is (110±10) N.
3.1.3 Damping spring
As shown in Figure A.3 of Annex A, the spring constant is (17.54±0.88) N/mm, the spring profile is rectangular (8.5mm×4.2mm) with a length of (165±5) mm, outside diameter of (44.5±0.5)mm and inside diameter of (28±0.5) mm, and the total number of coils is (17±0.5).
Note: measure the spring properly according to the frequency of use to ensure the performance parameters of spring comply with the requirements; it should be measured at least once every 8×104 times of use.
3.1.4 Impact bar
As shown in Figure A.4 of Annex A, dimensions shall meet the requirements hereof.
3.1.5 Damping rubber block
As shown in Figure A.5 of Annex A, arrange a cylindrical damping rubber block respectively at both ends of the damping spring, of which the outside diameter is (100±5) mm, height (30±3) mm, central hole diameter (22±2) mm, main material is thermoplastic polyurethane and hardness Shore A (85±3). The central hole of lower damping rubber block shall ensure the impact bar pass through freely and smoothly.
3.1.6 Fixture
It comprises common fixture and fixture for double shoulder straps. As shown in Figure A.6 and Figure A.7 of Annex A, the fixture for double shoulder straps may be installed in common fixture, which, however, shall be lined with flexible rubber spacer inside to avoid sample abrasion. The flexible rubber spacer is 10mm thick with hardness of Shore A (75~80).
The weight of fixture for double shoulder straps is (1.35±0.05) kg and the dimensions shall meet the requirements of Figure A.7 of Annex A. Double shoulder straps shall be fixed to such fixture for testing.
3.1.7 Control device
It is capable of adjusting the shaking impact rate, setting and recording the impact test cycles, and is provided with automatic shutdown function in case of falling down of sample halfway.
3.2 Sample fixing material
Cow split suede leather, with thickness of 1.5mm~2.0mm, width of (100±5) m and softness of 1.5mm~2.5mm (test hole diameter of 25mm).
4 Sample Preparation
Keep the sample under the temperature of 16℃~30℃ for at least 2h, during which the sample shall not be pressed, and conduct the test under such temperature.
5 Test Method
5.1 The specified load shall be evenly applied in the sample case or bag body.
5.2 Close the case or bag to prevent the load from dropping out during the test, envelop and fix the test parts of case or bag under test, e.g. handle (side handle), shoulder straps and trolley, with sample fixing materials to common fixture (dedicated fixture shall be used for double shoulder straps).
——In the test of shoulder straps, the shoulder straps shall be adjusted to the maximum length;
——In the test of double shoulder straps and handles, both shoulder straps or handles shall simultaneously be fixed to special fixtures of shaking impact tester for case and bag;
——In the test of trolley, the trolley shall be adjusted to the maximum length.
5.3 Selection of test mode
——Free fall: the sample is lifted to the preset stroke height and released by the sucker to make free fall motion under the action of gravity; test parts: handle (side handle), shoulder straps, etc.;
——Reciprocation: the sample is lifted to the preset stroke height but not released by the sucker to make reciprocating motion; test parts: trolley.
5.4 Test frequency is set as (20±2) times/min preferentially or the specified test frequency may apply.
5.5 The following shaking impact times shall be selected in the test, i.e. 100, 200, 300, 500, 1000, etc., or the specified times may apply.
5.6 After the end of test, inspect the handle (side handle) and trolley for falling off or any damage, metal fittings for any damage, stitches for any fracture or loose thread, case (bag) body for any deformation or damage, or other defects that may affect the appearance and use function.
5.7 Place the case or bag with trolley on the trolley fatigue tester, pull and push the trolley for 5 times to measure the pulling and pushing force.
6 Expression of Results
Results are expressed by the shaking times and apparent quality of product after the test.
——The shaking times is recorded as per that at the end of test;
——The test shall be ended if the handle (side handle) or trolley is damaged during the test;
——As for sample with trolley, the maximum pulling and pushing force, in N, shall be recorded and the result is rounded off to integer.
Foreword i
1 Scope
2 Principle
3 Devices and Materials
4 Sample Preparation
5 Test Method
6 Expression of Results
7 Test Report
Annex A (Normative) Structural Diagrams for Main Components of Shaking Impact Tester
