What are the applications of silicone sealants?
Source:iotachem.com
PostTime:2023-08-17 11:15:33
Nowadays, insulating glass has become the most common door and window material. Since the use of insulating glass, its production has gone through double glass, simple double glass, manual single-channel sealing, double-channel sealing, and composite adhesive strip type insulating glass in recent years. The production has gradually developed from the early manual production to the current semi-automatic or automatic production, and the production capacity, technical level and quality level have made great progress. How can we manufacture high-quality insulating glass?
At present, there are mainly three types of hollow glass production processes in China: 1. Aluminum groove single-channel sealing; 2. Aluminum groove double-channel sealing; 3. Composite sealing strip type.
Among them, the grooved aluminum single-channel seal, because of its poor sealing performance, is easy to enter moisture, which is easy to cause condensation and frost on the glass, and the service life will be greatly reduced. The raw materials of the latter two types of insulating glass are mainly: glass, aluminum strips, gussets, butyl rubber, silicone cavity glue, desiccants, composite sealing strips and other materials, which are also the current mainstream production forms.
Five factors that affect the quality of insulating glass!
1. Selection of glass:
1. Generally, the original glass for manufacturing insulating glass includes colorless float glass, coated glass, tempered glass, laminated glass, etc. Ordinary flat glass should be avoided in the production process, because its transparency and strength cannot meet the requirements and cannot meet the corresponding standards.
2. Before cutting glass from different manufacturers and batches, first check whether there is any color difference. Once the batches are found to be different, it is recommended to correct the color difference.
3. The glass cutting size should be strictly implemented according to the requirements of the drawings. At the same time, the operator should pay attention to the glass surface, and there must be no obvious defects such as scratches and bubbles.
2. Selection of aluminum bars and insert angles
1. The thickness of the aluminum spacer should be between 0.3-0.35mm, the thickness should be uniform, and the holes should be uniform. Aluminum strips must be bent after anodic oxidation or decontamination treatment. It is necessary to choose aluminum strip products with good quality and high grade, so as to improve the utilization rate of aluminum strips.
2. The size of the gusset should be selected properly, and the surface should be wiped clean. It is strictly forbidden to use the aluminum strip when the size and model do not match the gusset.
3. The hollow glass high-frequency welding aluminum spacers are divided into two types: bending and non-bending. They are all high-quality primary aluminum, which has good heat insulation, sound insulation, aesthetics and practicality, and can reduce the load-bearing section of the building itself.
3. Desiccant
At present, there are three main types of hollow glass desiccants: 1. The one with better absorption capacity for volatiles; 2. The one with the lowest adsorption capacity for inert gases; 3. Ordinary molecular sieve.
Users should choose the appropriate molecular sieve according to their own needs, and the molecular sieve must have a suitable particle size (1-1.5mm) and hardness. In addition, the environment where molecular sieves are used should be dry, and the filled molecules should be used within 1.5 hours to ensure the quality of insulating glass. Insulating glass molecular sieve is directly related to the final adsorption effect of insulating glass. It is recommended to use high-quality 3A molecular sieve.
4. Selection of sealant
1. Butyl rubber:
Butyl glue is the first seal for aluminum strip insulating glass. It is a hot-melt adhesive with low water vapor transmission rate (the lowest among insulating glass glues) and high viscosity. It is the most effective barrier to block water vapor between the side of the aluminum strip and the glass, but it needs to be heated, pressurized, and extruded on both sides of the aluminum strip by a special machine.
Butyl rubber has excellent adhesion to glass and aluminum frames, high air tightness and high bonding strength; excellent UV resistance and water tightness; wide operating temperature range and good extrusion processability. It is the first choice for making the first sealant material of high-quality insulating glass.
2. Silica gel
Silicon tunnel sealant has structural properties, aging resistance and anti-ultraviolet properties, but its main weakness is its high water vapor transmission rate. Therefore, silica gel is suitable for places with strong light and poor environment, such as glass curtain walls, etc. At the same time, butyl rubber must be used as the first seal. Silicone glue is used as the second seal of the insulating glass, which directly affects the sealing effect of the insulating glass. Therefore, it is recommended to use a guaranteed manufacturer's brand, and at the same time, try to ensure that the butyl rubber and silicone glue are from the same manufacturer.
5. Composite sealing strip
This is a composite sealing material developed by American chemists in the 1980s. The rubber strip is an insulating glass raw material that integrates the supporting frame (wavy aluminum strip), sealing (butyl rubber), and drying (desiccant).
Its biggest advantages are simple operation process, less waste of raw materials, less personnel, low management cost and good operating environment. The disadvantage is that the rubber strip absorbs moisture slowly and must have special equipment. At present, the rubber strip is limited by the output and the price is high. The selection of the composite sealing rubber strip should consider the smooth surface, the quality of the aluminum strip, the content of the glue, and the moderate viscosity.
