Currently,external thermal insulation materials of China market mainly use expanded polystyrene board (eps), extruded polystyrene board (xps), polyurethane (pu), rubber powder polystyrene particles, inorganic thermal insulation mortar, etc. Among them, eps and xps melt in fire Dripping can easily cause the spread of fire. The CCTV building is XPS, and the Changchun fire is eps. Pu melts and drips after encountering a fire, which will form carbon, but will produce a large amount of toxic smoke, which is more harmful. In addition, if the polyurethane is not added with flame retardants, the oxygen index is only about 16, which is a flammable product, and the fire risk is not small. The rubber powder polystyrene particles have good fire resistance and will not spread. However, due to the low threshold, they have been rotten. Among the many rubber powder polystyrene particles, the amount of polystyrene particles is very small, mainly cement mortar, and cannot be used for heat preservation. The role of. Inorganic thermal insulation mortar, due to its own shortcomings such as high water absorption, high thermal conductivity, and easy to empty drum cracking. It was restricted as early as in the north. Now it is called vitrified microbead mortar. The fireproof performance is good, but the thermal insulation performance and durability It is questionable.
In addition, products such as rock wool and glass wool have also begun to be applied under the promotion of national policies, but the inherent problems of high water absorption, easy pulverization, high thermal conductivity, poor durability and other issues need to be paid attention to. In addition, there are problems with skin during construction. Stimulus, and environmental issues in the production process.
Phenolic foam has low thermal conductivity, good fire resistance and easy construction, which is the development direction. However, the overall level of my country’s phenolic foam industry is low at present, and the product quality is unstable. Problems such as powder drop, water absorption and strength of the product are worthy of attention. Research needs to be vigorously carried out. However, from the perspective of both fire prevention and heat preservation, phenolic foam is worthwhile The research direction has no flaws at least in terms of essential issues.
EPS is the most mature for thermal insulation applications, and the thin plaster system is also the most suitable for it. After adding a fire barrier, it can be used in some ordinary buildings and should continue to be used;
Since the birth of xps, there have been constant controversies. Problems such as high strength, poor air permeability, difficult bonding, and dimensional stability have always been hidden dangers to engineering quality. There are many engineering applications, and the most engineering problems occur, such as falling off, cracking, and emptying. Drums and so on, there are so many;
At the beginning of the application of PU, it appeared as a high-end thermal insulation material, with the lowest thermal conductivity and the best thermal insulation performance. The systems are also diverse. Among them, the on-site spraying system is the most popular, but there are few successful cases of on-site spraying systems. The quality is very unstable due to the influence of, wind, etc., it is difficult to achieve the effect of publicity. In addition, other on-site pouring, sheet pasting, integrated sheets, etc., have a small application area and are difficult to judge. Originally, PU was able to take advantage of its on-site spray molding in the reconstruction of existing buildings and dry-hanging curtain wall system, but the fire in Shanghai basically cut off its survival;
Rock wool and glass wool can also be used in specific fields, but in the field of room temperature insulation, there are too many problems to be solved. In addition, whether my country’s resources can support its large-scale application is also a problem. However, the current national policy It is very advantageous, but I don’t know whether Adou can be supported. Phenolic foam has just started and has a bright future. I personally think that curtain wall insulation and integration are more suitable for application. However, basic scientific research needs the promotion of national policies and industry Work together.
In short, China’s research on thermal insulation materials, thermal insulation systems, and building energy efficiency is not enough, the research is not enough, there are few original things, there are few people who deeply analyze problems, and the road is still long.
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