There is still great room for development in the future of polyurethane material industry
In recent years, China's rapid development of the market building energy-saving wall insulation, thermal insulation system products emerge in endlessly, but in front of the fire accident emergency, a lot of heat preservation material is very weak, the management departments at various levels strictly to strengthen the wall thermal insulation material in the fire protection problems in the process of popularization and application, its importance is far more than any time in the past. How to ensure that building materials have fireproof performance and can withstand fire in the case of emergency fire becomes a very important index to measure whether a building is qualified or not.
To prevent fire accidents, on October 1, 2013, the ministry of public security fire department officially released the building materials and products of combustion performance GB8624-2012 classification of national standard, the standard to replace the original standard GB8624-2006 "building materials and products of combustion performance classification", to the division of application products of combustion performance rating and grading criterion for the modification, increase the combustion performance of special-purpose products classification, modified the additional information and combustion performance rating marks, etc. The promulgation and implementation of this standard plays an important role in improving the fire safety of building materials and products in practical engineering application, reducing fire hazards, standardizing the production of enterprises and facilitating the supervision and management of supervision departments.
Polyurethane, as one of the most excellent insulating materials, has been widely used in various buildings in China, making great contributions to national building energy conservation. However, because of people's cognition to the very limited, plus some insulation fire accidents in recent years, and even don't know much about the market for pu heat preservation material produce misunderstanding on and construction units in construction process of shoddy phenomenon common occurance, lower prices and inferior products flooding the market in great quantities, and so on factors have hindered the healthy development of polyurethane materials.
To understand the polyurethane insulation performance and its fire resistance, it is necessary to understand the product structure and application of polyurethane.
Polyurethane, known as polyurethane, is the general term for large molecular compounds containing repeated carbamate groups on the main chain. It is formed by the addition of organic diisocyanate or polyisocyanate with dihydroxyl or polyhydroxyl compounds. Polyurethane material USES is very wide, can substitute for rubber, plastic, nylon and other materials, widely used in all kinds of buildings, its resistance to deformation ability is strong, not easy craze, facing stability, security, and such products of low thermal conductivity, thermal performance is good, it is the lowest heat preservation material coefficient of thermal conductivity of excellent thermal insulation products, this product belongs to the hydrophobic material, moisture-proof, waterproof performance and special superiority, also has the freezing-thawing resisting ability. What is worth mentioning, polyurethane, after adding flame retardant is a kind of flame retardant material, self-extinguishing its softening point can reach more than 250 degrees Celsius, will appear only in high temperature decomposition, even burning situation of the polyurethane appear again will form carbon deposition in the bubble surface, this layer of carbon help to isolate the bubble below, can effectively prevent the spread of flame, this kind of excellent fire, flame retardant, high temperature resistant performance is a incomparable other class insulation products. The polyurethane insulation composite board produced by this kind of polyurethane can even meet the requirements of B1 level standard, which is a rare excellent insulation product among many insulating boards. At present, when the issue of fire prevention is increasingly emphasized, the choice of thermosetting polyurethane material with B1 level fire protection is the only choice in the market. Although the polyurethane insulation board has such excellent performance, in the actual market promotion application, because most of the manufacturers are restricted by the production equipment and production technology, although meeting the building's requirements for safety and energy conservation, the promotion work is affected by the price factor.
In fact, at present, the flame retardant grade of polyurethane external wall insulation products in the insulation material market is mostly below B2 level, and the oxygen index is less than 26. Only in this level can the price of buildings requiring B1 level materials compete viciously, so as to occupy a certain market share. It is said that this has been an unspoken rule and an open secret in the construction sector, and it is no wonder that fire is prone. According to the requirements of the national standard GB8624-2012, polyurethane can achieve B1 level, but most of the factories produce the B1 level according to the standard products, due to its production process USES the method of adding flame retardant increased to improve the flame retardant performance, influence the number of the receiver, and by increasing the density to meet the requirements of the size stability, which in turn increases the costs. In this case, the status quo of the market is shoddy, and the low-grade masquerading as a high-level fire rating often occurs, thus laying a hidden danger for the safety of the building itself.
According to relevant data, the application of polyurethane insulation material is very common in foreign markets, the application amount of polyurethane insulation material in American market reaches 57%, in Japan over 32%. In contrast, the application of polyurethane in China's building insulation material market is less than 10%. Even in such cases, due to the irreplaceable safety and energy saving, the polyurethane industry is still 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.
But, in our country each year under construction and completed the project, the fire accident, including some project USES is polyurethane composite board exterior insulation system, since this will give the construction unit, construction unit, relevant departments and people caused a misunderstanding: polyurethane thermal insulation performance is not good, fire prevention performance is poor. Obviously, this misunderstanding should not be true for the entire polyurethane industry, and the damage to the entire industry should not exist.
All of them can only be verified through more practical engineering applications that the polyurethane insulation performance is excellent, is worthy of great promotion. Of course, in the process of promotion and application, we should eliminate backward production capacity, purify the market of the industry, and strengthen the supervision of the market. Only all the practitioners of the polyurethane industry gather together and prove to the market with practical actions: polyurethane insulation is both heat preservation and fire prevention, and it is trustworthy.