Energy conservation and environmental protection promote the development and application of insulating glass products

The development prospects of hollow glass and hollow glass processing industries are promising. However, along with this, there are also some problems. Although the production capacity of insulating glass in China is close to 10 million square meters per year, the average operating rate is less than 50%, and the products are still in the middle. The number of low-level, high-level products is relatively small. In the face of opportunities and challenges, and the existing problems in the hollow glass processing industry, industry insiders pointed out that strengthening enterprises to handle well the cooperation among professional enterprises and fraternal associations and seek skills innovation and quality upgrade is inevitable. Hollow glass processing industry will also be of great use. Enterprises should actively develop new products, new processes, new skills, and new equipment for insulating glass.

After more than a century of development, hollow glass has gained a lot of applications, especially in the 1950s. In particular, in the 1970s, the oil crisis in the future, Western developed countries recognized the seriousness of power, and energy conservation became a long-term policy. . The construction of energy-saving products has become the main stream for the construction of occupations in the world. Many developed countries have guided, inspired and standardized the construction of building materials malls through the development of product skills, technical guidance, application of legislation and other aspects, and there is ample scope for the use of energy-saving building materials. The pace of development of our country's power is lagging far behind the pace of economic development. The energy consumption of external walls has been used to build doors and windows, and the heat insulation and airtightness of external walls is an urgent problem facing us. This is the development of insulating glass products. And the implementation of the application provides a basic guideline.

1. Structure of insulating glass

Insulating glass, also known as insulating glass, is composed of two or more glass plates. The space between the glass plates is separated by a partition, so it is usually called an insulating glass. According to the different address of the insulating glass, the original data and structure of the insulating glass are not the same. For example, in the southern region, where the temperature is high throughout the year and the illumination time is longer, when considering the use of insulating glass, more consideration is given to the control of external heat to enter the room. When selecting the insulating glass original film, there will be more. Consider using coated glass. In the northern region, the primary purpose of the use of insulating glass is to adopt warm insulation, so more consideration will be given to using bright glass as the original insulating glass. In areas where noise control is required, three layers or inflated hollow glass are used to achieve the intended use.

With the development of the economy, the product category of insulating glass has also been expanded. The types of raw materials used have also been added. For example, insulating glass for curtain walls, insulating glass for windows and doors, insulating glass for cars, insulating glass for electric appliances, and decoration Hollow glass, all of these products, although the use is different, the use of the original data are the same, but the basic composition is the same, namely: glass, sealant, desiccant, spacer. In all the original materials constituting the insulating glass, the function of the sealant and the desiccant has a great influence on the service life of the insulating glass product. When considering the energy saving problem, the heat conduction function of the distance strip and the sealant will be directly Affects the insulation of the edge of the insulating glass, and then affects the overall insulation of the doors and windows.

After several decades of development, the hollow glass production technology has been continuously improving its thermal insulation and sound insulation functions. From the earliest welding method, welding method to cemented aluminum strip method, the heat insulation and sound insulation functions of the products have made great progress. After the oil crisis of the 1970s, people discovered that aluminum strip products and edge heat insulation were necessarily poor and it was necessary to improve them to improve the insulation of the entire hollow glass. By the early 1980s, the world's first warm-edged hollow glass system was introduced. The marginal heat insulation function was improved, and the overall heat insulation effect was better, so that the use of insulating glass products has a broad perspective.

2, the function of insulating glass

(1) The most outstanding function of insulating glass is insulation and heat insulation. When the building uses a single-story window, the greenhouse effect will occur when the sun shines on the summer sun. That is, part of the sunlight that shines on the glass reflects into the room and the temperature rises. In winter, because the thermal conductivity of the glass is large, the single-layer window serves to dissipate heat. Insulating glass can reduce conduction heat transfer and can also reduce convective heat transfer and radiation heat transfer.

1 cuts the conduction heat transfer: Between the two pieces of glass of the hollow glass there is a gas with much lower thermal conductivity than the glass, so the thermal conductivity of the hollow glass is much smaller than the single glass.

2 reduce convection heat transfer: Insulating glass in the outdoor ice face glass plate on both sides of the temperature difference is small, so cut the ice face through the air convection heat conduction.

3 Cut radiation heat transfer: The heat radiated from a high-temperature object to a low-temperature glass is related to the radiation emissivity of the object. The radiation emissivity of the glass is larger than 0.82. If a layer of low-radiation film is coated on the glass, it can be made Radiated calorie reduction plays a role in insulation. If the insulating glass is coated with a sun visor film and a low-radiation film on both surfaces of the insulating glass, the hot sunlight is blocked in the summer and the heat loss in the room is avoided in winter, and the intention is that it is warm in winter and cool in summer.

(2) Anti-condensation, falling cold radiation and safety functions of insulating glass Since there is a desiccant inside the insulating glass that can adsorb water molecules, the gas is dry, and when the temperature drops, the inside of the insulating glass does not condense. Dew phenomenon. Together, the condensation on the exterior and exterior of the insulating glass will also increase. For example, when the outdoor wind speed is 5m/s and the room temperature is 20 degrees, the relative humidity is 60%, 5mm when the outdoor temperature is 8 degrees, the condensation begins. . The 16mm hollow glass under the same conditions, the outdoor temperature of -2 degrees dew condensation, 27mm3-layer hollow glass in the outdoor temperature of -11 degrees before the beginning of dew condensation. Because of the better insulation of the insulating glass, the temperature difference between the two sides of the glass is larger. It can also reduce the effect of cold radiation. When the outdoor temperature is -10 degrees, the temperature in front of the single-layered glass window is -2 degrees, and the temperature in front of the insulating glass window is 13 degrees. In the same house structure, when the outdoor temperature is -8 degrees and the indoor temperature is 20 degrees, the 3 mm general single-glazed cold radiation area accounts for 67.4% of the indoor space. The use of double hollow glass 9mm is 13.4%. The use of insulating glass can improve the safety function of the glass. Under the condition of using the original glass of the same thickness, the wind-resistant strength of the insulating glass is 1.5 times that of the ordinary single glass.

3. Ways to improve the skills of hollow glass

(1) Thickness of gas-distance layer: First of all, through manipulation of the thickness, the internal of the hollow glass forms a turbulent flow of heat, and the hot and cold gases that manipulate the gas are disturbed as much as possible, or they are disturbed by the rising and falling air currents. To control the convective heat transfer.

(2) Gas species and humidity in the air layer: Inert gas filled in the interior of the insulating glass can reduce the heat insulation and sound insulation of the insulating glass. Such as argon and sulfur fluoride can be separated to improve the insulation and sound insulation of insulating glass.

(3) Sealing condition of the edge of the insulating glass: On the one hand, if the edge of the insulating glass is not well sealed, the proportion of water vapor entering the hollow glass through the sealant layer should be increased, and the life of the insulating glass will be reduced. On the other hand, if the thermal conductivity of the edge of the insulating glass is good, then the thermal insulation coefficient of the insulating glass will improve and the thermal insulation function will decrease.

(4), glass thermal transmittance: Insulating glass heat transfer is mainly carried out by the method of radiation heat transfer, if the selection of high transmittance and low reflectance of the general bright glass, the insulating glass insulation function, the use of high reflection The low-transmission coating or LOW-E glass is much lower.

(5) Glass plane dimensions: Increasing the plane dimensions of the insulating glass can reduce the heat loss per unit area of the insulating glass and improve the overall heat insulation of the insulating glass. Together, in the process of installing insulating glass doors and windows, if the glass buckles are not properly installed or the seals are not tight, the entire window or glass surface will become air-permeable and convection will occur, resulting in energy loss and affecting its function. The development of domestic hollow glass shopping malls followed the needs of insulating glass shopping malls. From the 60s to the present, more than 200 hollow glass production lines have been established in China, 70 of which are imported into the country, and the country’s total production capacity is approximately 12 million square meters. Insulating glass supporting materials, such as key sealant, were mostly imported before the 1990s, followed by the increase in the demand for insulating glass in domestic shopping malls, so that insulating glass production units and supporting seal materials (silicone, polysulfide sealant and silicone sealant) Both the R&D and production have made great progress in the direction of localization. The production process of insulating glass has experienced welding, welding and bonding. It is still dominated by adhesive bonding. The new-generation adhesive tape process has also entered the China market. The new process of the tape is an integrated process integrating butyl rubber, corrugated aluminum tape, and desiccant. It completely eliminates the need for operations during the manufacturing process. Installed sealant makes the process simple and easy to operate. Its production value and price are completely used to the change of the market. It is favored by customers in domestic shopping malls for its superior sealing, excellent heat insulation, reliable application quality and durable life. Because the hollow glass has been among the energy-saving construction data team, the Ministry of Construction listed the hollow glass as one of the building energy-saving products that was formally implemented and implemented on October 1, 2000 in the Civil Building Energy Conservation Management Rules. China's hollow glass as an important construction of energy-saving materials is facing outstanding achievements and opportunities. From the perspective of domestic shopping malls, the production and demand of insulating glass is increasing year by year, and the trend of shifting the eastern products to the west has become increasingly evident. The virtual integration of technological skills, materials, and equipment in the eastern region with the western region has taken initial shape. From an incomplete set of statistics, it can be seen that the production and use of insulating glass in shopping malls in China are on the rise.