The application of silicone sealant in curtain wall doors and windows of the building mainly includes three aspects: hollow glass second seal, sealing curtain wall structure, weathering and doors and windows of the waterproof sealing. The quality of the silicone sealant affects not only the safety of the whole building door and window curtain wall structure, but also related to the building meets the requirements of environmental protection and energy saving.
Insulating glass insulating glass unit with outstanding thermal insulation performance is an important material to improve the energy efficiency of windows and doors, and has been widely used in building in recent years. Hollow glass internal dry gas to make hollow glass with sound insulation, heat insulation, anti condensation, reduce the cold radiation and enhance the safety glass and other functions.
In the hollow glass structure of the two seal, the seal is to ensure that the low water vapor penetration, the general use of hot melt butyl rubber. The second role is to ensure the integrity of the sealant and glass structure is selected as the silicone sealant. If it is used for insulating glass structural assembly, you must use silicone sealant.
The service life of the insulating glass unit depends on the function of the sealing structure, and the excellent edge seal must have the following characteristics:
1 durable resistance to environmental factors and especially the heat, water or moisture and ultraviolet radiation;
2 enough structural strength to withstand the displacement, making the first - way sealing glue steam passage of the smallest;
3 low moisture and gas permeability under the conditions of use.
If silicone sealant can not meet the above requirements, then the sealing hollow glass is likely to in use period, the fog phenomenon may lead to the failure, loss of energy saving effect.
China building glass and industrial glass association to develop the HBZ/T0O1-2OO7 "hollow glass production code" in the 2OO7 7 release of the implementation of 1. The majority of domestic glass manufacturers strictly according to the standard requirements of the hollow glass of raw materials selection and construction. But in the fierce market competition, industry still has some sealant manufacturers set the quality of the products in disregard, in order to reduce the production cost and one-sided pursuit of short-term interests, in the insulating glass sealant added "white". Due to the low price of "white", and can let the appearance after curing sealant has better gloss, some negative the responsibility of manufacturers even this as a selling point to the user of the product publicity and promotion.
With the passage of time, add "white" hollow glass sealing adhesive tape to a series of serious quality problems gradually appear, outstanding performance: the sealant such service life of insulating glass is generally short, there are a large number of leaks, leakage and condensation phenomena, more serious is the insulating glass sealant in the "white" to infiltrate into the sealant is hot melt butyl sealant, butyl rubber is softening swelling and flowing, resulting in hollow glass "tears" phenomenon.
Curtain wall structure, weather sealing and doors and windows sealing curtain wall by the panel and the structure composition, belonging to the building envelope, hanging on the outside of the main structure, can with the main structure deformation, to force transmission to the main structure. As a symbol of modern architecture, curtain wall, especially glass curtain wall in the world has been more and more widely used, application of large area glass plate, for the construction provides good daylighting performance and aesthetic design, but also energy-saving weak link.
In the past in the industry attention has been given to energy efficiency of energy-saving doors, windows and curtain walls, the focus of most is how to choose the low thermal conductivity of hollow glass, how to improve the inflatable hollow glass of inert gas retention rate, how to design the section of the cavity structure to reduce heat conduction \ glue injection heat insulation selection also is nylon insulation and so on, and the choice of silicone sealant did not cause enough attention. In fact, has a very important significance of silicone sealant quality performance of energy-saving doors and windows curtain wall effect. Alfalfa, structural silicone sealant for curtain wall plate durable good adhesive is curtain wall security guarantee, and silicone weatherproof sealant directly affect the whole curtain wall, windows and doors airtight water and dense of, in fact, seal failure led to the loss of energy consumption far than choose better glass and profiles to save more, who also can not imagine to talk about the topic of building energy saving and environmental protection in the building of a leakage, leaking.
Silicone weatherproof sealant products mainly used in plate curtain wall waterproof seal, silicone products outstanding anti ultraviolet aging properties make its application in this outstanding performance. But if the improper material, such as the use of silicone sealant is bad, in addition to its weathering failure, sometimes penetrated into the road of hollow glass sealing, resulting in butyl rubber is dissolved, resulting in the failure of the hollow glass at the same time as shown in Figure 6, this example will happen, in practice often also, bonding the poor quality of silicone sealant can also cause the curtain wall joints is not good, caused by damage to the Water Leakage curtain wall joints and causes indoor decoration as shown in Figure 5 and figure 8 in the actual project, will encounter some larger plate seam size changes, ordinary sealant products will appear unable to meet the demand and displacement ability lead to fatigue cracking conditions such as high requirements for big size plate with the silicone sealant displacement capacity of the launch for 5O level of the displacement capacity of silicone weatherproof sealant and skylight special sealant products, more than the national standard of weatherproof sealant displacement capacity requirements, led the development of the industry.