Silicone structural adhesive is devoted to the design and construction of metal curtain walls. Its main component is silicon dioxide, and the key raw material is methyl silicone oil. And timeliness. It is a safe, economic development and perfect way of building structure interface. Because the silicone structural adhesive itself is a stable, solid, and reliable engineering building structural product from the aspects of raw material performance, bonding principle, and use performance, etc. The joining process has become a key element in pinning the construction quality of metal curtain wall projects.
Therefore, today's net braids take everyone to master the silicone structural adhesive.
1.Type selection
For hidden frame and semi-hidden frame curtain wall glass, the bonding of laminated glass and aluminum alloy profiles uses neutralized silicone construction sealant. When glass curtain walls are used for all-glass building curtain walls and point-supporting building curtain walls, acid-base silicone sealants cannot be used for bonding. The weather-resistant adhesive is generally selected from silicone type, because the silicone structural adhesive has excellent properties such as weather resistance, oxygen resistance, active oxygen resistance, ultraviolet light resistance, high temperature resistance, and low temperature resistance.
2. Norms in Practice
The performance of neutralized silicone structural sealants and acid-base silicone structural sealants for building curtain walls should meet the requirements of the current standard industry standard "Silicon Structural Adhesives for Buildings" GB-16776. GB-16776 is a compulsory industry standard, which clearly stipulates that the service life of the silicone structural sealant for metal curtain walls is not less than 25 years, which is more scientific and rigorous than the relevant regulations in the world in the past. It is safe for metal curtain walls. Precautions.
3. Test and inspection
Before the application of the silicone structural sealant, the compatibility and debonding experiments of the raw materials in contact with each other should be carried out by a nationally recognized testing center. Aluminum alloy materials should be surface anodized, electrophoretic coated, electrostatic powder sprayed or fluorocarbon sprayed. When the surface of the aluminum alloy profile is selected by organic coating, the construction record of the silicone structural rubber topcoat should be checked to improve the adhesion and reliability.
4.Key performance of silicone structural adhesive
Adhesiveness: Defined as the adhesive properties of the sealant on a given substrate. Adhesion relies on page physics suction, ionic bond conversion, and mechanical device teeth to maintain the connection. Excellent adhesion is essential to ensure that the sealant maintains its function. Silicone structural adhesives are used for adhesion experiments with substrates for specific engineering projects.
Compatibility: It is defined as the performance of the sealant and the surface of other raw materials that do not cause poor physical reflections between each other. Other raw materials generally refer to backing raw materials such as foam plastic rods, foam double-sided adhesives, and vulcanized rubber strips. Compatibility is the basis to ensure that the sealant maintains its own performance. The silicone structural adhesive and construction assembly line system software use compatibility notes for compatibility experiments.
Use period: It is defined as the time that elapses from the time when the sealant is placed in the joint to its ineffectiveness. It is directly related to the Rashen adhesion performance after high and low temperature test, immersion and ultraviolet light irradiation. The specifications for the embrittlement standard require maintenance of the compressive strength of the sealant after the time required for the embrittlement standard is small, but according to the relevant work experience and the European standard bottom judgment method, the compressive strength after embrittlement should be calculated The ratio to the compressive strength under standard conditions, that is, the compressive strength maintenance rate, should be as large as possible.
Performance of glue joints: Because the design and service life of large and medium-sized and extra-large buildings is more than 50-100 years, and some exceed 100 years. This stipulates that the service life of the building curtain wall of the outer frame structure is not less than the service life of the building construction. In solving the anti-corrosion solution of embedded iron parts, the fatigue resistance limit of aluminum alloy profiles, the thermoelectric erosion of metal structures, the performance and life of laminated glass have become the most important concerns of design concepts and users. . Because the silicon-oxygen bond in SiO2 is very stable, its excellent use performance is determined at the level of organic chemical structure.
5. Basic requirements for project construction
The building curtain wall is produced and processed in a production workshop with an envelope structure, and it has measures such as fire safety, explosion protection, and pollution prevention. In addition, the homogeneity, initial setting, and dry-solid level of the silicone structural adhesive are tested daily according to relevant standards. The natural environment of the project construction should be carried out under the cleaning standard of 10-40 degrees and air humidity of 40% -80%. The construction team must understand the weathering adhesive construction technology, grasp the position of the adhesive seal and the raw materials of the supporting facilities as required in the construction drawings. Using common tools, the one-component weatherproof adhesive can be extruded with a manual or pneumatic glue gun. The component weatherproof rubber is refilled with a special refilling mixing equipment.
6. Actual level of project construction
Eliminates stains, dirt, surface damage, and loose air oxide films on the surface of the substrate during the entire manufacturing process. It roughens the surface of the substrate and produces a surface shape suitable for the function of the tissue chimera. It also improves the surface organic chemistry Performance to improve performance under the hazards of environmental factors. The cleaning organic solvents are generally isopropyl alcohol, methyl ethyl ketone and xylene. The cleaning cloth should be a milky, clean, soft, non-hair-removing cotton cloth.
The cleaning of the surface of the substrate is carried out by the "double cloth scrubbing" method, which is infiltrated and cleaned with organic solvents. The surface of the substrate can only be cleaned in one direction. Immediately before the organic solvent evaporates, wipe off the organic solvent on the surface of the substrate with a second dry-cleaning cloth.
To ensure the safety of building curtain walls, silicone structural adhesives cannot be ignored. This is some professional knowledge related to silicone structural adhesives combed by net editors. If everyone has a large number of more technical and comprehensive professional knowledge, please leave a message board to inform the net editor. From time to time, I will carry out a large number of relevant professional knowledge of the building curtain wall manufacturing industry that everyone wants to master, and I look forward to everyone's continuous concern for the card-capable building curtain wall.