Safety shoes are the collective name for safety shoes. As the name implies, it is to protect the safety of the footsteps and eliminate or reduce the shoes that hurt the foot and legs.
Safety shoes are high-tech products, so the technical content required for materials and requirements is higher.
Then, the following small series collects some national standards for safety shoes.
The European standard EN 344:1997 (special safety, protection and work shoes) is developed by the CEN/TC61 Technical Committee on "Protection of Foot and Legs" and the secretariat is chaired by BSI.
This standard specifies the structural design and performance indicators of safety shoes, such as shoes, uppers, shoes, tongues, insole and outsole. The test methods for each item specified in the standard are similar to other similar standards. The method principle is also generally applicable to most safety shoes. The main indicators are:
A, safety shoes - Baotou impact resistance
The hammer is impacted by the specified weight, and the impact is less than the specified value after the impact of the toe cap. The fearless flaw does not appear in the direction of the test axis, and it meets the national standard for safety shoes.
Note: The national standard has different regulations on the weight, specifications, impact height and construction of the test machine.
B, anti-piercing performance
The test is carried out on a test machine equipped with test nails (the test nail is a tip-cutting head, the hardness of the nail head should be greater than 60HRC) and the pressure plate. The sole sample is placed on the chassis of the testing machine in such a position that the test nail can be pierced through the outsole, and the test nail pierces the sole at a speed of 10 mm/min ± 3 mm/min until the penetration is completed, and the maximum required for recording is recorded. force.
Note: Select at least 4 test points on the sole and one of them must be a heel. ≥ 30 mm between each test point and > 10 mm from the inner bottom edge.
In addition, the bottom of the anti-slip block should be pierced between the blocks. Two of the four points should be tested within 10-15 mm of the edge line of the bottom of the plant.
If humidity affects the results, the sole should be immersed in deionized water at 20 degrees Celsius ± 2 degrees Celsius for 16 ± 1 h before testing.
C, electrical properties of conductive shoes and anti-static shoes
A clean steel ball is placed in the dried and moisture-conditioned shoe and placed on a metal probe device to measure the resistance between the first two probes and the third probe using a specified resistance test instrument.
Note: Conductive shoes require resistance ≤ l00KΩ; anti-static shoes require resistance should be between 100KΩ-100MΩ.
D, thermal insulation performance
Taking the shoe as a sample, the thermocouple is placed at the center of the insole connection area, and the steel ball is filled in the shoe. Adjust the temperature of the sand bath to 150 degrees ± 5 degrees, place the shoe on it, make the sand contact the outsole of the shoe, and measure the temperature of the insole and the corresponding time using a temperature test device connected to the thermocouple. , gives the temperature increase curve. Calculate the temperature increased from the time the sample is placed on the sand bath for half an hour.
Note: General insulation shoes require an increase in temperature of the inner sole surface <22 degrees.
E, energy absorption performance of the heel part
The test instrument has a maximum compression load of 6000 N and is equipped with a device for recording load/deformation characteristics. The shoe with the heel is placed on a steel plate, and the test punch is placed on the inner side of the heel portion against the insole. The load was applied at a speed of 10 mm/min 3 mm/min. Draw the load/compression curve and calculate the absorbed energy E, denoted by J.
F. Requirements for anti-slip outsole
This standard stipulates the anti-skid coefficient of the sole, but specifies the design and specifications of the anti-skid block, such as the thickness of the sole, the height of the non-slip block, and the distance from the edge of the sole.