Application of Group Angle Glue in Energy Saving of Aluminum Doors and Windows
At present, energy conservation and environmental protection have become one of the themes for human beings to improve their living environment and seek for healthy development. With the economic development and the continuous improvement of people's quality of life, building energy consumption has accounted for more than 40% of national energy consumption, and it has become a part of energy consumption. As an indispensable part of the building envelope structure, doors and windows can ensure the lighting and ventilation of the building, improve the aesthetics and comfort of the building, but at the same time, it is also the most energy-consuming factor in the building envelope. Studies have shown that [1, 2], in building energy consumption, the energy consumption caused by glass doors and windows accounts for about 50% of the total energy consumption of buildings; among them, the energy consumption analysis of [3] multi-storey buildings in the literature shows that doors and windows Heat dissipation accounts for more than one-third of the total heat dissipation of the building. Therefore, improving the energy-saving performance of doors and windows has become the key to achieving building energy efficiency. Energy-saving doors and windows with new energy-saving materials, efficient insulation systems, and energy-saving technologies such as lighting and sunshade design can reduce energy consumption of the entire building by nearly 40% [4]. Insulated broken aluminum doors and windows are favored by the majority of owners because of their excellent energy saving, sound insulation, noise prevention, dustproof and waterproof functions. In the production process of such doors and windows, the necessary cutting and assembly process is inevitable. Simply relying on sophisticated cutting equipment, proper corner joints, and angled corners of the corners of the corner unit are easily damaged by various forces during production, transportation, installation, and long-term use [5] . The use of special set of angle glue can effectively solve the corner problem of aluminum doors and windows, improve the heat insulation, air tightness, water tightness and sound insulation of aluminum doors and windows, and ensure the energy saving effect of aluminum doors and windows. This paper gives an overview of the reasons for the formation of the corner of the aluminum door and window, the role and characteristics of the group of angle glue, and the current status of the application of the angle glue.
1 corner problem formation cause
1.1 temperature difference
The material itself usually causes a certain stress due to the change in temperature, which is expressed as a linear expansion/contraction rate.
The dimensional change of the aluminum alloy profile over the normal operating temperature range, ie the linear expansion/contraction rate, is:
Where - the length after the change;
- the original length;
——Expansion/contraction coefficient, in the range of -40~50°C, its value is 2.4×10-5°C;
- Celsius temperature change value.
Calculated by the formula, the change amount of the 1m long aluminum alloy profile under the temperature difference of 90 °C in the range of -40~50 °C: the change rate of 2.16mm is enough to make the parts of the corner of the door and window dislocation or deformation, causing the corner The strength and sealing performance are degraded, and energy saving is even more difficult to talk about.
1.2 external force
Many ubiquitous, inevitable and occasional external forces caused by deformation stress can cause corner problems of doors and windows, such as: different degrees of collision and knocking during production, transportation and installation; door and window installation is completed After that, the long-term effect with its own weight and the static stress of the window opening and wall deformation; the vibration of the switch window, wind pressure, ambient sound wave and so on. These can cause airtightness, heat insulation, sound insulation and dust-proof performance of doors and windows to be degraded. In severe cases, the door and window will be deformed, which is the main reason for the energy consumption of doors and windows.
The role and characteristics of 2 sets of Jiaojiao
In order to solve the corner problem of aluminum doors and windows, aluminum doors and windows that meet the requirements of energy-saving performance are produced. It is effective to use a set of corner sealant designed for doors and windows (referred to as a set of corner glue), corner code or insert and profile cavity The wall is bonded, and the structure is strengthened and sealed to prevent misalignment of the door and window frame due to temperature difference and external force deformation, thereby ensuring the airtightness, heat insulation, sound insulation and dust separation of the door and window.
Therefore, the performance of the group of corner glue needs to meet: (1) high hardness, high strength, good toughness, can make the structural connection between the corner code and the wall of the profile cavity, and also has excellent waterproof performance; (2) Slightly foaming and expanding, forming an elastic pad between the metal and metal connection, to weaken the conduction of various forces, and function as a shock absorber and a cushion; (3) Good aging resistance, and can withstand -40 ° C ~ 80 Temperature change of °C.
At present, the professional group of corner glue is mostly polyurethane sealant. Polyurethane adhesive structure contains very strong polarity and chemically active -NCO (isocyanate), -NHCOO- (urethane group), and has excellent chemistry for materials such as metal, glass and plastic. Adhesive strength, high strength, hardness and excellent impact resistance, suitable for a variety of structural bonding areas, through formula and process design can meet the performance requirements of the group of corner glue.
Current status and development prospects of application technology of 3 sets of angle glue
The application status of 3.1 sets of angle glue
With the implementation of energy-saving and consumption-reducing measures in China, the construction industry has gradually transformed the door and window curtain wall and energy-saving design as an important development direction of building energy conservation. Therefore, the application of the group of angle glue has been paid more and more attention. However, due to the late development of China's door and window energy-saving technologies, there are still many problems in the application of corner and door sets of corner glue.
The first is the problem of counterfeit group glue. The above mentioned that the professional group of corner glue is a polyurethane type sealant which can meet the performance requirements, and has the characteristics of high hardness, high strength and good aging resistance. Some door and window factories mistakenly use silicone rubber, epoxy glue, etc. as a special set of corner rubber for aluminum alloy doors and windows. The silicone rubber has low hardness after curing, and the elasticity is too large. The gel does not swell when solidified, and the corner code cannot be made. It is tightly bonded to the cavity, and the epoxy adhesive is inelastic, easy to be thickened and broken, and can not adapt to the micro-shock of the window. It will crack and slag when used for a long time.
Secondly, many production plants have not completely established a unified standardized production process. The requirements for the construction time and curing speed of the set of angle rubber are different. It is necessary to select a suitable set of angle glue to better guarantee the product quality. According to the survey, there are two main production processes for the production of doors and windows for corner glues, namely the open injection molding process and the overall injection molding process. (1) Open injection molding process: directly extrude the corner glue to the inner surface of the cavity of the profile, insert the corner code, connect the two sections of the profile, and fix the angle of the upper group angle unit. The process requires sufficient construction time. In order to prevent the group of corner glue from curing, it can not be effective; (2) The whole glue injection process: directly insert the corner code to connect the two sections, the upper set angle unit is fixed and prefabricated, and the prefabricated hole is Glue injection until the card point has glue overflow. This process is a standardized production process that is currently popularized. It requires the group of corner glue to be cured quickly in a closed environment. Generally, the two components are cured by two components. Polyurethane group angle glue, and single-component polyurethane group angle glue, relying on room temperature moisture curing, curing is relatively slow, generally not recommended.
Once again, it is a polyurethane group of corner glue designed according to market demand. The single-component and two-component products have great differences in technical parameters. For example, the single-component group of angle glue is simple in operation and convenient in construction. Generally, it can be completely cured after seven days. The shear strength can reach 6 MPa or more, and it can be foamed and expanded after curing. The two-component group of corner glue needs special glue-making equipment. Fast curing, short construction time, hardness after curing can reach shoreD70 ~ shoreD80, shear strength can reach more than 10MPa, after expansion can be slightly expanded but not foaming. It can be seen that the single-component group angle has better shock absorption and buffering effect, but the curing is slow, and the effect on the production efficiency and the corner strength is far less than that of the two-component group. There is currently no tangible evidence to prove which type of gelatin is more effective.
Finally, there is a lack of authoritative industry standard specification group of corner rubber performance indicators, technical description often only describes the surface dry time, construction time, curing speed, final shear strength, it is difficult to ensure the door and window corners in the long-term use process There is no problem in the middle. According to the investigation and investigation, our company adopts harsh high temperature and high temperature and high humidity aging projects, and refers to the technical specifications, construction guidelines and test reports of similar foreign products, and cites the formulation of performance indicators such as climate change, cold strength and heat strength. The enterprise standard Q/ZZY037-2015 "Polyurethane corner glue for building doors and windows".
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