The polyurethane insulation material industry still has great development space in the future

In recent years, China's building energy-saving wall insulation market has developed rapidly, and insulation system products emerge in endlessly. However, in the face of sudden fire accidents, many insulation materials appear very fragile. Management departments at all levels have strictly strengthened the fire prevention problem in the promotion and application of wall insulation materials, and their attention has been far greater than any previous period. How to ensure that building materials have fire performance and can prevent fire in case of sudden fire has become a very important indicator to measure whether buildings are qualified.

In order to prevent fire accidents, on October 1, 2013, the Fire Department of the Ministry of Public Security officially issued the national standard GB8624-2012 for the classification of the burning performance of building materials and products, which replaced the original standard GB8624-2006 Classification of the Burning Performance of Building Materials and Products, modified the classification and grading criteria of the burning performance of applied products, and added the classification of the burning performance of products for specific purposes, The additional information and combustion performance grade identification are modified. The promulgation and implementation of this standard plays an important role in improving the fire safety of building materials and products in practical engineering applications, reducing fire hazards, standardizing enterprise production and facilitating the supervision and management of supervision departments.

Among many thermal insulation system materials, polyurethane, as a kind of excellent thermal insulation material, has been widely promoted and applied in various domestic buildings, and has made great contributions to the national building energy conservation cause. However, due to people's limited awareness of polyurethane insulation materials, the occurrence of some thermal insulation fire accidents in recent years, and the lack of market understanding of polyurethane insulation materials, even misunderstandings, the phenomenon of construction units passing inferior materials for superior ones is common in the construction process, and a large number of cheap and fake products are flooding the market, which hinders the sound development of polyurethane materials.

In order to understand the thermal insulation performance and fire resistance of polyurethane in detail, it is necessary to understand the product structure and application of polyurethane.

The full name of polyurethane is polyurethane, which is the general name of macromolecular compounds containing repeated carbamate groups on the main chain. It is formed by addition polymerization of organic diisocyanate or polyisocyanate with dihydroxy or polyhydroxy compounds. Polyurethane materials have a very wide range of uses. They can replace rubber, plastic, nylon and other materials. They are widely used in various buildings. They have strong deformation resistance, are not easy to crack, and their finishes are stable and safe. Moreover, they have low thermal conductivity and good thermal performance. They are excellent thermal insulation products with thermal conductivity * * among the current thermal insulation materials. They are hydrophobic materials. Their moisture-proof and waterproof properties are also particularly excellent, and they also have the ability to resist freezing and thawing. It is worth mentioning that polyurethane is a flame retardant self extinguishing material after adding flame retardant. Its softening point can reach more than 250 ℃, and it will decompose only at a higher temperature. Even if polyurethane burns, it will only form carbon deposits on the surface of its foam. This carbon deposit helps isolate the foam below, and can effectively prevent flame spread. This kind of excellent fire prevention, flame retardancy High temperature resistance is also unmatched by other types of thermal insulation products. The polyurethane thermal insulation composite board produced by this kind of polyurethane can even meet the requirements of Class B1 standard. It is one of the few excellent thermal insulation products among many thermal insulation boards. At the moment when the fire protection problem is increasingly emphasized, the choice of thermosetting polyurethane materials with Class B1 fire protection requirements is the best choice in the market. Although polyurethane insulation board has such excellent performance, in the actual market promotion and application, most manufacturers are restricted by production equipment and production technology. Although they meet the requirements of safety and energy conservation for buildings, the promotion work is affected by price factors.

In fact, the flame retardant grade of polyurethane exterior wall insulation products in the current insulation material market is mostly below B2, and the oxygen index is less than 26. Only such a grade can lead to vicious price competition on buildings requiring B1 materials, and can it occupy a certain market share. It is said that this has been an unspoken rule and an open secret in the field of construction. It is no wonder that fire is easy to happen. According to the requirements of the national standard GB8624-2012, polyurethane can completely reach Grade B1, but most manufacturers produce Grade B1 products according to the standard. Because the production process adopts the method of increasing the addition of flame retardants to improve its flame retardancy, which affects the number of senders, and by increasing the density to meet its dimensional stability requirements, which in turn increases the cost. In this case, the current market situation is characterized by shoddy products and low-grade products posing as high-grade fire protection grade, which often causes hidden dangers to the safety of the building itself.

According to relevant data, polyurethane thermal insulation materials are widely used in foreign markets, with 57% of polyurethane thermal insulation materials used in the U.S. market and more than 32% in Japan. In contrast, the application of polyurethane in the market of building thermal insulation materials in China accounts for less than 10%. Even in this case, due to its irreplaceable safety and energy conservation, the polyurethane industry is developing at a high speed every year in China. With reference to the situation of developed countries, there is much room for improvement in the future.

However, in the projects under construction and completed every year in China, the fire accidents are alarming. Some of the projects use polyurethane composite panel external wall thermal insulation system, which has caused misunderstanding to the construction units, construction units, relevant departments, and people: polyurethane has poor thermal insulation performance and poor fire protection performance. Obviously, this misunderstanding should not be applied to the entire polyurethane industry, and the damage caused to the entire industry should not exist.

All of these can only be verified by more practical engineering applications that the thermal insulation and fire protection performance of polyurethane is excellent, which is worthy of being vigorously promoted and applied. Of course, in the process of promotion and application, we should eliminate backward production capacity, purify the industry market, and strengthen the supervision of the industry market. Only all practitioners of the polyurethane industry can unite and prove to the market with practical actions that polyurethane insulation is both thermal insulation and fire protection, which is trustworthy.