First, Can we find a kind of high-efficiency and environmental protection thermal insulation material suitable for the use of building energy-saving field: second, whether the material is flame-retardant, whether it has toxicity in the process of fire, and how much harm it has to human body; third, whether it has constructability, whether it can meet the construction and use requirements of building external wall external insulation; fourth, whether it can realize industrial scale production Whether it can meet the development needs of the industry, whether it is worth promoting; fifthly, whether it can be recycled in the life cycle.

With the continuous improvement of people's understanding of environmental protection, the requirements of building energy conservation and emission reduction are also higher and higher. As a new high-efficiency energy-saving material, polyurethane has been widely used in the world.

1、 The thermal conductivity is low. Under 0.025, good thermal conductivity can reduce the area of external insulation and increase the effective living area of indoor. The building area of 100 square meters can be increased by 1.5 square meters to 3 square meters. It can also effectively reduce the thickness of the building, and has good seismic effect.

2、 It has good flame retardancy and fire safety. It can meet the requirements of BL standard. It is difficult to ignite, and the oxygen index is above 30, which is far higher than 25 of ordinary organic thermal insulation materials. Due to its unique chemical structure, when exposed to open fire, the surface will react quickly when heated to produce a carbonized layer with high temperature above 900 degrees. The key technology of fire protection is to form carbonized layer. Only the foam structure of carbonized layer can resist fire and high temperature attack, so as to prevent fire spread, that is, it has the function of resisting fire.

We did experiments in Europe for 61 minutes, and the side facing the flame was completely burned down, but a relatively stable uniform carbonization layer was formed, and there was no complete combustion. When the side facing the flame is heated, it reaches 500 to 900 degrees, but the other side which is not exposed to fire is stable below 100 degrees for a long time. This kind of material is used in Europe as fire isolation belt. One is to make fire isolation belt between buildings, and the other is to make fire isolation belt in front of windows. This research has been done since December 15, 2005. After the fire isolation belt is made, the internal structure is intact.

3、 The smoke density is low and the smoke smell is less. The smoke has less irritating smell and low toxicity, which is conducive to escape and will not cause rapid edema of respiratory tract due to odor stimulation. Ordinary thermal insulation material products will burn rapidly in case of open fire, and the smoke density released during combustion process is as high as 1.00. It is found that the toxicity of polyurethane is very low below 200 ℃ and 300 ℃. Only when the temperature is between 600 ℃ and 700 ℃, the toxicity will be reduced in the later stage.

From the product paper model, compared with EPS, XPS and other building insulation materials, the cost of polyurethane insulation materials is indeed some high. In particular, the fluorine-free rigid polyurethane insulation material is higher than the former and the manufacturers in the same industry in terms of equipment cost and raw material cost, so it does not have an advantage in the product paper model. However, with the continuous increase of national building energy-saving efforts, the continuous improvement of energy-saving standards, especially the increasing awareness of the masses of people on energy-saving, if you can consider the environmental protection, flame retardant, safety, and its long-term energy-saving effect and other factors, I think polyurethane insulation materials must have high cost performance, such as Europe Like developed countries, it has become the main product in the field of building energy conservation in China, which is also the general trend.