Commonly Used External Wall Insulation Materials
Commonly used external wall insulation materials
As the self-insulated wall system has been unable to meet the higher energy demand, and external wall insulation system is reasonable and has obvious advantages compared with the internal insulation and clamping insulation system, so for now, it’s the vigorously promoted thermal insulation system in China.
The use of external wall insulation material is related to the choice of thermal insulation materials, according to different regional conditions, China's current external wall insulation system mainly includes powder polystyrene particles insulation system, thin plaster expanded polystyrene board Insulation system and polyurethane rigid foam insulation system. The insulation system of colloidal polyphenylene particles is made of polystyrene foam, which is an insulating material made of cement. Thin plaster expanded polystyrene board system is the insulation board with adhesive bonded to the external wall; Polyurethane hard insulation materials are mixed with two kinds of chemical raw materials to form the organic foam body, which is sprayed by pressure on the surface of the wall.
The above mentioned insulation materials are organic materials, these materials are light, low water absorption, thermal insulation performance is good, but there are many problems in the construction use. First of all, in the construction of polybenzene particle insulation system, because it is wrapped with cement polystyrene particles, which has certain difficulty in bonding together, and also the polystyrene particles are resilient, which makes it more difficult to smear on the wall, especially in the corners of the wall; polyurethane rigid foam insulation materials are greatly affected by the weather, windy weather is not possible to construct, and the spray thickness is difficult to master; The polystyrene board should be used after soaking the surface of the wall in the construction, and then be sticked to the surface, the construction operation is tedious. Second, it is well known that organic materials have poor fire resistance, which will produce large amounts of smoke after burning, thus it’s harmful to the human body and the environment. Improper welding operation can also cause a fire in the construction of polystyrene board insulation system, such as during a building construction in Tianjin, the workers ignited the tile surface layer of benzene board in the welding operation, because the benzene board is in the protective layer of internal combustion, thus can not be remedied, resulting in a huge economic losses. In addition, the durability of organic insulation materials is poor. Organic insulation materials are susceptible to sunlight and other environmental factors, which are easily aging. According to statistics, the designed service life of benzene board is generally 25 years, but by the quality of benzene board, aging time and construction and other reasons, the actual life may be less than 20 years, and the former building design life is 50 to 100 years. This means that each time the wall insulation system will be refurbished once, which is not only detrimental to the building's thermal insulation, but also cause huge waste of resources. Therefore, recently, some experts appeal to develop insulation material with the same service life of the building, thus insulation materials can only choose from the inorganic materials.
However, current inorganic materials, such as expanded perlite, mineral wool, rock wool, etc., although with good fire-proofing and durability characteristics, yet the material capacity is relatively larger, thermal conductivity is relatively higher, so the insulation effect is poor. And, perlite inorganic insulation material is open-hole structure, which determines its high water absorption, and has great impact on energy-saving effect.