![<?echo $_SERVER['SERVER_NAME'];?>](/template/twentyseventeen/skin/images/header.jpg)
Building energy conservation has become one of the most important issues facing the construction industry in China. According to the latest figures, China's building energy consumption has accounted for about 40% of the total national energy consumption. Polyurethane (PU) is the most excellent insulation material, and the application of building exterior insulation materials is becoming more and more common.
1 Polyurethane foam insulation material has excellent thermal insulation properties. PU rigid foam has a high closed cell ratio, and its closed cell ratio is over 90%. The gas sealed in the closed cell is mainly a foaming agent (HCFC-1411), 0:2, etc. with a low thermal conductivity. The initial thermal conductivity of PU hard foam sprayed on site is generally around 0.020W/(nrK;), and its aging thermal conductivity is generally around 0.023W/(mK). Its low thermal conductivity, good thermal insulation effect, is unmatched by any other thermal insulation materials.
Good waterproof performance. PU rigid foam material has unique hydrophobicity and high closed cell structure (90%~95%), which makes it have high water vapor permeability barrier and good gas barrier properties, and can effectively block water inside the thermal insulation material. Longitudinal flow. PU hard foam in the foaming process, the contact surface with air will form a dense skin, not easy to see through the water.
Easy to construct. PU rigid foam plastic has strong self-adhesiveness with cement concrete, plywood, metal plate, wood board, fiberboard and other materials, and its bonding strength exceeds the tear strength of the foam itself, so that the PU rigid foam and the roof base layer become One, it is not easy to delamination. There is no need to re-treat the roof base during construction, and it can be directly constructed. There is no special requirement for the roof exterior, and construction work can be carried out on any complex roof. The equipment and process are very simple, easy to operate, and easy for construction personnel to master.
High flame retardant properties. PU rigid foam itself is a kind of polymer flammable material. The PU hard foam oxygen index without flame retardant treatment is only about 17, and a large amount of 10, (02: toxic gas is released during the combustion process to give fire and fire escape. All of them bring great difficulties. At present, the flame retardant requirements for building insulation materials in most areas of China are oxygen index greater than 26, and some regions even up to 32. To improve the flame retardant properties of foam materials, many units have conducted research. And made some progress. ZL polyurethane rigid foam material adopts the method of adding composite flame retardant to make the foamed plastic oxygen index of 27. The red Baoli company has studied for many years in the flame retardancy of foam. Great progress has been made. Not only has the PU hard foam with an oxygen index greater than 26 been successfully developed, but it has been applied to sheet metal and on-site spraying systems. In 2003, a highly flame-retardant PU rigid foam with an oxygen index of 32 was successfully developed. Get the application in the on-site spray system.
PU rigid foam also has excellent physical and mechanical properties, electrical and acoustic properties and chemical resistance. The roofing waterproof insulation layer is made by spraying PU hard foam, and after being properly protected, the service life is up to 30 years, and usually no maintenance is required.
2 Polyurethane foam board polyurethane rigid foam insulation board is firstly coated with a reinforcing cloth inside, and then coated with an outer layer to protect the powder. All components in the system include insulation materials, adhesives, expansion screws, reinforced cloth, mortar, etc. as a whole package. The insulation board can be attached to the outside of the wall with expansion screws and adhesives or with only adhesive. This type of insulation board can be used for brick walls, concrete walls and wooden walls. The insulated connection system can be used both in new buildings and in old buildings.
Experts recommend the use of 100mm thick polyurethane rigid foam board, the heat transfer coefficient of the polyurethane insulation connection system is characterized by convenient structure connection, the use of thin insulation layer, and can make the wall surface show a quality aesthetic.
3 spraying polyurethane flooding insulation system building roof is sprayed with PU rigid foam for waterproof insulation, its structure is very simple, generally spray a layer of 30~50mm thick foam directly on the roofing substrate, plus a protective layer .
The construction process of spraying PU hard foam roof is as follows: base layer cleaning - roof leveling and finding slope - spraying PU hard foam construction - protective layer construction - protective layer curing - expansion joint construction.
The construction principle of spraying PU rigid foam is to use high-pressure airless spraying foaming machine, and the two raw materials A and B are respectively injected into the spray gun by the metering pump, uniformly mixed in the mixing chamber under the action of high pressure, and then sprayed in a low pressure form. Rapid foaming is formed to form a continuous dense and seamless foam on the surface of the building.
The biggest characteristic of PU is that it is greatly affected by the environment. Its production process and product performance change with the change of environmental conditions. The construction of PU hard foam is mostly carried out outdoors. The environmental conditions are different and difficult to control. It must be corrected in time according to the site conditions during the construction process. The following points should be noted in the construction: the base layer of the building should be kept dry (the water content should be less than 8%), and there should be no floating ash and oil on the surface.
The atmospheric temperature at the construction site should not be lower than 15X: the relative humidity of the air should be less than 85%, and the wind should not be greater than 3.
The construction work surface shall be sprayed in several stages. The thickness of the first layer shall not exceed 10mm. The thickness of each layer above shall be controlled within 20mm. The surface of the previous spraying shall not be applied to the next layer after spraying.
When working in high altitude and windy days, anti-flying should be done.
Since the sprayed polyurethane directly foams on the wall, it can be firmly bonded to the base layer, the insulation layer has no joints, and the wall forms a seamless joint without any joints, which is suitable for any shape structure and is convenient for modification. However, it is necessary to pay attention to the weather conditions and the proficiency of the spraying technology during construction. It is necessary to solve the environmental problems such as splashing and floating of the spray foam, and the thickness needs to be uniform. It is necessary to master the flatness and solve the problem of adhesion to the surface layer. Improper handling can easily cause the phenomenon of drumming, falling off, cracking, etc. of the finish layer.
4 pouring polyurethane insulation system pouring method is to inject foam polyurethane in the closed template, no splash in the foaming process, to achieve zero loss and zero pollution, the surface flatness of the insulation layer is effectively controlled by the template. Since the foaming polyurethane has large expansion ratio and high speed, the external expansion force is also large. How to solve the structural influence of the external expansion force on the template and improve the construction efficiency has always been a technical problem of the pouring method construction.
The main problems of on-site mold-casting foamed polyurethane technology are: the outer wall insulation layer can be constructed on the façade, and the construction method of pouring foamed polyurethane can adopt two construction methods: detachable template and person-made template. The detachable template is used after the casting and the template is removed, that is, the template is used as a reusable machine; the template is not removed after casting, that is, the template becomes a polyurethane protective layer and can also be a finishing layer. The test proves that the two construction methods can not only complete the high-level insulation layer, but also can be normally constructed in the thin template (thickness <4mm).
Therefore, it is possible to apply the heat-insulating waterproof decorative integrated decorative panel into the pouring concrete outer thermal insulation technology for the high-grade exterior wall and roofing finishing works, and develop the detachable formwork technology into a paint finish, a tile finish or Roof insulation and waterproofing works.
The detachable template casting polyurethane technology is to solve the technical problems of reliable and simple positioning, simple and quick removal, no damage to the insulation layer, template anti-adhesive technology, and no expansion and deformation of the template during pouring.
From the relationship between polyurethane technology formula, casting process parameters and environmental humidity and temperature, the selection of pouring equipment is improved to improve the quality of pouring construction. Currently, there is a set of domestically developed ones independently developed by Yantai Tonghua Waterproof and Insulation Engineering Co., Ltd. TH thin foam polyurethane composite panel exterior insulation system for wall plastering system, and TS field mold-cast polyurethane thermal insulation system developed by Harbin Tianshuo Building Materials Industry Co., Ltd.
TH hard foam polyurethane composite panel exterior insulation system is composed of TH polymer cement mortar adhesive (with anchor), TH rigid foam polyurethane composite board, alkali resistant mesh cloth, TH polymer surface glue layer Wall insulation system. The outer wall thin plastering system also shows its superiority, such as protecting the main structure, extending the life of the building, basically eliminating the phenomenon of “cold bridgeâ€, and integrating the thermal insulation and decoration, which is more conducive to maintaining the stability of the indoor temperature.
The TS field mold-cast polyurethane exterior insulation system consists of a polyurethane insulation layer, an interface layer, a protective layer, an auxiliary rigid reinforcement layer, and a finish layer. Firstly, the foamed polyurethane is cast by the detachable sliding stencil technology, then the surface treatment is carried out with a special interface agent, and the protective layer and the finishing layer are completed by using a special polymer mortar with an alkali-resistant mesh cloth and a flexible anti-cracking putty, and a highly elastic coating; After surface treatment with a special interface agent, the leveling layer is completed with a special leveling glue, a galvanized steel mesh and a TOX nylon sleeve steel nail, and then the surface is finished with a special glue paste tile. This method can be combined with dry hanging stone to complete the supporting technology of external thermal insulation. It can also be used for roof insulation and waterproofing. It has wide adaptability to new residential buildings, public buildings and existing building energy-saving renovation projects.
Because polyurethane foam has better insulation effect than other insulation materials, coupled with the rapid development of polyurethane materials, the world's energy-saving requirements, the state's emphasis on building energy conservation, polyurethane foam in building insulation materials will be more widely used.
(Finish)
Melamine Blockboard,Melamine Board Vs Blockboard,Melamine Faced Blockboard,Melamine Vs Blockboard
LINYI JIUHENG IMP&EXP CO.,LTD , https://www.jiuhengwood.com