Research and revision of the main technical contents of safety shoes

The revised standard name is “Foot Protection Electric Safety Shoes”, which adds the guiding word “foot protection” and deletes the “general technical conditions” in the original standard name. In fact, since its implementation, GB 12011-2000 has been implemented as a product standard. It is used by manufacturers, government regulatory agencies, inspection agencies and users to evaluate the quality of electric safety footwear products. A generic product name is fine. The introduction of the guiding words is to be consistent with the requirements of the 11th Five-Year Plan for personal protective equipment, and is also convenient for standard retrieval.

2. General requirements for research and revision results

The general requirements include the technical requirements for the physical and mechanical properties and the wearing performance of the shoes and their components. This is a place where the standard content has been changed greatly. The purpose is to make the technical content close to the international standard and improve the non-electrical performance. So that it can effectively guarantee the quality of the product. Because GB 20991-2007 and GB 21146-2007 are modified to adopt international standards, the technical content is basically consistent with international standards, and GB 21146 adopts the test method of GB20991, so based on the technical content of fully digesting and absorbing these two standards. The general requirements and corresponding test methods of GB 12011-2000 have been supplemented and revised. The main changes in the technical content of the new standard and the old standard are as follows:

a) In terms of requirements for safety uppers:

The requirements and measurement methods for the height of the safety upper are modified, and the requirements of 5.2.1 of GB 21146 are adopted. The test method is 6.2 method of GB20991;

The requirements for the thickness of the safety upper are the same as the original standard, and the measurement method is changed, and the method of 6.1 of GB 20991 is adopted;

The requirements and test methods for leather tear strength (new standard name tear resistance) were modified. The requirements for the tear strength of fabric uppers were increased by the requirements of 5.4.3 of GB 21146. The test method is 6.3 method in GB20991. The old standard only requires leather upper tear strength;

The requirements for tensile properties of rubber and polymeric uppers and the test method for tensile properties of rubber uppers were modified. The requirements of 5.4.4 of GB 21146 were adopted. The test method is 6.4 of GB 20991;

Increased folding resistance, water vapor permeability and coefficient, pH value, hydrolysis, hexavalent chromium content and test methods for safety uppers, and increased resistance to folding of rubber and polymeric materials in terms of folding endurance According to the requirements of 5.4.5 in GB 21146, the test method is 6.5 method in GB20991; and the requirements for water vapor permeability and coefficient, pH value, hexavalent chromium content, hydrolysis and other test methods of the upper are GB 21146 and GB20991 respectively. The corresponding requirements and methods.

b) In terms of requirements for outsole:

Increased the requirements and measurement methods of the anti-skid pattern and thickness of the outsole to make it more specific and more comprehensive;

The requirements for the external bottom tear strength and the test method are increased, and the requirements of 5.8.2 of GB21146 are adopted, and the test method is 8.2 of GB 20991;

The requirements and test methods for the wear resistance and folding resistance of the safety shoe outsole have been modified. Because of the differences in the wear resistance of the outsole for shoes with different materials and different pressure levels, reference is made to the use of 5.8.3 of GB 21146. Claim. And according to the test situation, it has been re-specified; the folding resistance is in accordance with the requirements of 5.8.4 in GB 21146, and the test method is 8.3 and 8.4 in GB20991;

Added the requirements and test methods for the hydrolysis of soles with polyurethane outer sole and outer layer of polyurethane material, using the requirements of 5.8.5 of GB 21146, the test method is 8.5 in GB20991;

The requirements and test methods for the bonding strength of the middle layer of the multi-layer sole are increased, and the requirements of 5.8.6 of GB 21146 are adopted, and the test method is 5.2 of GB 20991;

c) In terms of requirements for safety shoes:

Increased the appearance requirements of all-polymeric shoes, using the relevant requirements of QB 1471-1992;

The requirements and test methods for the peel strength of the outer bottom are changed to the requirements and test methods for the bonding strength of the upper/sole. The requirements of 5.3.1.2 of GB 21146 are adopted, and the test method is 5.2 of GB 20991.

It should be noted that this standard revision does not put the requirements of lining, insoles and insole in GB21146, mainly considering the domestic testing cost and the bearing capacity of the enterprise, and will not affect the safety performance of safety shoes. And physical and mechanical properties of the main components (safety shoes upper, outsole).

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