Over the past 20 years, China's rapid development of polyurethane industry. Because this product has very low thermal conductivity and water vapor permeability, light, high strength, coupled with its paper, metal, wood, cement, brick, plastic plate, asphalt felt, etc., with a strong adhesive, and other advantages, has been used for many industrial and civil. However, polyurethane is a kind of highly combustible polymer with other organic polymer materials. The density of rigid polyurethane foam is small, the insulation performance is good, and the exposed surface of the outside world is larger than other materials, so it is easier to burn. With the wide use of polyurethane foam, the problem of fire resistance and fire protection has become an urgent need to solve the important issues.
In our country, due to accidentally ignited polyurethane foam and cause fire events occur from time to time, to the application of polyurethane foam brought some negative effects. Many experts in foreign countries even think that this problem is one of the key to the future development of rigid polyurethane foam plastics. Therefore, the fire resistance and safety of rigid polyurethane foam have become an important technical index for building materials. In many countries, a series of building laws and regulations have been worked out, and a series of testing methods for the performance of polyurethane foam plastics has been developed.
EU polyurethane standard has the following new requirements:
1, it's material combustion performance level of the division from the original five levels to A1, A2, B, C, D, E, F level seven levels.
2. The new standard of the European Union is a series of standards. The second and three or four parts of the EU are determined by the fire test. The fifth part is about the classification method of the external flame roof test.
3, the content of the polyurethane on the combustion characteristics of the flame spread and spread from the original, extended to include the amount of heat release, combustion smoke density and combustion toxicity and other parameters. At the same time, the European Union's new standard also provides some test method to consider the actual scene, and consider the end use of the material. So the new EU standards, is more practical and scientific, the original 1997 version of the standard should also be changed and international standards.
Based on the above reasons, the Chinese government in 2006 with reference to the EU EN13501-1 standard, the original GB8624-1997 version of our country made a comprehensive revision, the development of GB8624-2006 "building materials combustion performance classification method" new standards, which in addition to the B, C, A2 level increased the level of the material production, the other parts are completely consistent with EU standards.
In 2012, according to the situation of energy saving building in China, the Ministry of public security and the Ministry of public security have enacted and promulgated the GB8624-2012 "building materials and products burning performance classification" standard, which is now being implemented. The new national standard is basically along the learning GB8624-2006 version of the standard, but it has more stringent standards and inspection standards. It is classified by the level of the original GB8624-2006 test as the A1 level and A2 level corresponds to non burning level; the original GB8624-2006 test for B level and C level corresponding to the B1 level; the original GB8624-2006 test for D level and E level corresponding to the B2 level; the original GB8624-2006 test sentenced to D level and E level corresponding to B3.