windows and curtain walls
The importance of building energy efficiency

Energy is an important material basis for human survival and production. In recent years, China's economic construction has achieved world-famous achievements. At the same time, huge energy consumption has become the focus of attention of the world. The shortage of energy supply and the ecological and environmental problems brought about by energy consumption will seriously hinder the development of the economy and affect our living environment.

The National Bureau of Statistics recently released data that China’s total energy consumption in 2011 rose to 3.48 billion tons of standard coal. Among them, building energy consumption accounts for more than 28% of the country's total energy consumption. The energy consumption of buildings has risen sharply along with the continuous increase of the total amount of buildings and the improvement of living comfort. According to the current development forecast of building energy level, by 2020, China's building energy consumption will account for about 35% of the total energy consumption of the whole society, surpassing industrial energy use and becoming the first field of energy use.

Promoting building energy conservation is mainly to improve the insulation performance of building envelopes. Among the several main components of the building envelope, the thermal insulation of the curtain wall and the doors and windows is poor, which is the main factor affecting the indoor thermal environment and building energy conservation. Therefore, increasing the thermal insulation performance of the door and window curtain wall and reducing energy consumption are important links to improve the indoor thermal environment quality and improve the building energy efficiency level.

The infrared spectrum of ordinary doors and windows shows that a large amount of heat is radiated to the outside through the glass. The infrared spectrum of the energy-saving windows and doors shows that the heat radiated through the door and window glass is much less. The colors in the figure are green and blue respectively, which achieves the effect of heat preservation. The energy-saving effect of energy-saving doors and windows is achieved through the integrity of the entire door and window system, and the sealant material is an indispensable part of the whole system.

Application of Silicone Sealant in Building Energy-saving Door and Window Curtain Wall

The application of silicone sealant in building door and window curtain wall mainly includes three aspects: insulating glass two-way sealing, curtain wall structure, weatherproof sealing and waterproof and weatherproof sealing of doors and windows. The quality of silicone sealant not only affects the safety of the entire building door and window curtain wall structure, but also relates to whether the building meets the requirements of energy saving and environmental protection.

The insulating glass hollow glass unit has outstanding thermal insulation performance and is an important material for improving the energy-saving level of doors and windows. It has been widely used in construction in recent years. The dry gas inside the insulating glass makes the insulating glass have the functions of sound insulation, heat insulation, anti-condensation, reducing cold radiation and enhancing glass safety.

In the two seals of the hollow glass structure, the first seal is to ensure low water vapor penetration, and hot melt butyl rubber is generally used. The role of the second sealant is to ensure the integrity of the glass unit structure, generally selected silicone sealant. If it is an insulating glass for structural assembly, a silicone structural sealant must be used.

The service life of an IG unit is critically dependent on the functional retention of the seal structure, while an excellent edge seal must have the following characteristics:

1. Lasting resistance to environmental factors, especially heat, water or moisture and ultraviolet light;

2. Sufficient structural strength to withstand displacement, so that the first channel sealant water vapor channel changes minimally;

3. Low moisture and gas permeability under the conditions of use.

If the silicone sealant does not meet the above requirements, then the sealed insulating glass is likely to fail during the use period, resulting in failure and loss of energy saving effect.

The HBZ/T0O1-2OO7 "Insulating Glass Production Regulations" formulated by the China Building Glass and Industrial Glass Association was issued on the 1st of July 7th. Most domestic glass manufacturers strictly select and construct raw materials for insulating glass according to the standard requirements. However, in the fierce market competition, there are still some sealant manufacturers in the industry who disregard the quality of their products. In order to reduce production costs and pursue short-term benefits, “white oil” is added to the insulating glass sealant. Because "white oil" is cheap, and can make the sealant have a better gloss after curing, some irresponsible manufacturers even use this as a selling point to promote and promote products to users.

Over time, a series of serious quality problems with the addition of “white oil” insulating glass sealing tape have gradually emerged, highlighting the fact that the insulating glass made of such sealant has a generally short service life and a large amount of water leakage. , leakage and condensation, and more serious, the "white oil" in the insulating glass glue penetrates into the first sealant, that is, the hot-melt butyl sealant. The butyl rubber is softened and swelled and flows, resulting in insulating glass. "Flowing tears" phenomenon.

The curtain wall structure, weather-resistant seal and door and window sealing curtain wall are composed of panels and structures. They belong to the building's outer protective structure and are suspended outside the main structure. They can be deformed with the main structure and transmit the force to the main structure. As a symbol of modern architecture, curtain walls, especially glass curtain walls, have been used more and more widely in the world. The use of large-area glass plates provides good lighting performance and aesthetic design for buildings, but it is also a weak link in energy conservation. .

In the past, the energy efficiency of energy-saving windows and doors curtain wall in the industry, most of the focus is on how to choose hollow glass with lower thermal conductivity, how to improve the inert gas retention rate of the inflatable hollow glass, how to design the cavity structure of the profile to reduce heat conduction, select the injection gap Heat is also a nylon insulation strip, etc., but the choice of silicone sealant has not received enough attention. In fact, the quality of silicone sealant has a very important impact on the performance of energy-saving door and window curtain wall.

First of all, the long-lasting good adhesion of the silicone structural sealant to the curtain wall panel is the guarantee of the safety of the curtain wall, and the silicone weather-resistant sealant directly affects the airtightness and watertightness of the entire curtain wall door and window. In fact, the seal failure causes The energy loss is far more than the cost of using better glass and profiles. No one can imagine talking about building energy conservation and environmental protection in a leaky, leaky building.

Furthermore, the quality of the building silicone sealant affects the service life of the construction project and even the personal safety. Therefore, the China Building Metal Structure Association Aluminum Door and Window Curtain Wall Committee and the China Building Decoration Association Curtain Wall Engineering Committee regulate the use of silicone structural adhesives in building doors and windows and curtain wall projects, and strengthen the industrial management of silicone structural rubber production enterprises and products. Over the years, the company has carried out annual product sampling inspection of building silicone structural sealant production enterprises in the industry, and will release the latest annual inspection results through the official website of China's curtain wall network ALwindoor.com, providing options for Party A and design institutes. Reference basis.

Click to visit: 2016 annual inspection results of silicone structural sealant products for construction

Silicone weather-resistant sealant products are mainly used in weather-resistant waterproof seals of curtain wall panels. The outstanding UV-resistance properties of silicone products make them excellent in this application. However, if the material is not properly selected, such as the use of inferior silicone sealant, in addition to its own weathering failure, sometimes it will penetrate into the first seal of the insulating glass, causing the butyl rubber to be dissolved, thus causing the hollow glass at the same time. Invalidation, such an example often occurs in actual engineering. Similarly, inferior silicone sealant can also cause poor adhesion of curtain wall joints, causing water leakage in the joints of the curtain wall and causing damage to the interior decoration.

In actual engineering, when the seam size of some large plates changes, the ordinary sealant products may have difficulty in meeting the requirements and cause fatigue cracking. For the high-capacity plate, the high displacement requirements of silicone sealant, such as Baiyun, Zhijiang, Silicon Bao, Antai, Huasi, Zhongyuan and other first-line brands, have launched targeted 50-level displacement silicone sealant and The special sealing rubber products for doors and windows (lighting top) exceed the national standards for the requirements of the weathering sealant displacement capacity, leading the development of the industry.

The weatherproof and waterproof seal of doors and windows is the same as the curtain wall. It is a systematic project, including the sealing between the window frame and the glass, and the sealing between the outer wall and the window frame. The quality of silicone sealant also has an important impact on the performance of doors and windows. Some sealant products are filled with too much heavy calcium carbonate, so that the surface of the glue appears after the product is cured - a layer of white filler, and some products are selected and used. Improperly, the contact with the laminated glass causes degumming of the laminated glass, causing damage in appearance. The quality of silicone sealants is a direct factor in the watertightness and airtightness of doors and windows, while high quality silicone sealant products maintain long-lasting adhesion, air tightness and water tightness during use.

Summary: The value of silicone sealant only accounts for 3 to 5% of the entire curtain wall, door and window cost, but directly affects the quality and energy saving effect of the entire construction project. In order to achieve the best building energy saving and environmental protection seal energy saving effect. In addition to the design of the door and window curtain wall, whether the scientific construction management is reasonable or not, the correct selection of high-quality silicone sealant products is an important guarantee for building doors and windows and curtain walls to meet the building energy-saving requirements.