1. Classification of welders' safety shoes
1 normal type (HP), does not require heat resistant temperature.
2 Low heat resistance type (HN-1) requires a heat resistance temperature of 150 °C ± 5 °C.
3 High heat resistance type (HN-2) requires a heat resistance temperature of 250 °C ± 5 °C.
2. Technical requirements for welders' safety shoes
1 material requirements
The materials in the upper and shoes should meet the requirements of the following table:
The thickness of the unlined upper is 0.2mm as required by the following table. If sputum, horse, and camel leather materials are used, the provisions of the beef noodles in the above table should be referred to.
2 Outsole physical and mechanical properties: should meet the requirements of the above table.
3 The tolerance of each part of the same pair of shoes: It should meet the following requirements:
4 needle stitch density: 5 to 6.5 needles/cm for the thread and 4 to 5.5 needles/cm for the nylon thread.
5 appearance quality.
6 structural requirements: high waist molding process should be used to form shoes.
7 heat, heat insulation, insulation properties
a. heat resistance requirements
Place the shoes on a heating plate with adjustable temperature (250 °C ± 5 °C), put steel balls (5mm, 4kg in diameter) into the shoes and fill the sand around the shoes. The height of the sand reaches the upper edge, but not more than the upper. . When the temperature rises to 150 °C ± 5 °C (or 250 °C ± 5 °C), stabilize for 20 min. Cool to room temperature and observe that the sole should not melt, deform or separate. The high heat resistance type shall be heat resistant to 250 ° C ± 5 ° C without melting, deformation or separation.
b. Thermal insulation requirements
The test method is similar to the heat resistance test. Under the condition of 150 °C ± 5 °C, the inner surface temperature of the insole was recorded every 5 minutes within 40 min, and then the average temperature (starting from the time when the sample was placed on the hot plate) was calculated, which was compared with the insole before the test. The difference in surface temperature must not exceed 22 °C.
c. Insulation requirements: It should meet the requirements of GB 12011-2000.
8, the burning speed requirements of the upper: should not be greater than 1cm / s.
9. Protection of toe requirements: It should meet the requirements of An3 type (pressure resistance 4.4kN, impact resistance 23kg, weight drop height 120mm, deformation gap greater than 15mm).
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