Do you know all about these silicone structural sealants?

Silicone structural adhesive is designed and conceptualized for the construction bonding assembly line in metal curtain walls. Its main component is silicon dioxide, and the key raw material is methyl silicone oil, which has high-quality UV resistance, aging resistance, aging resistance, and timeliness. It is a safe, economically developed, and comprehensive interface method for building construction. Because silicone structural adhesive itself is a stable, sturdy, and reliable engineering building structural product from various aspects such as raw material properties, bonding principles, and usage performance, the hot welding process of silicone structural adhesive in on-site engineering construction has become a key factor in constraining the construction quality of metal curtain wall engineering.

Therefore, today the editor will take you to master silicone structural adhesive together.

1. Type selection

Neutral silicone sealant is used to bond the laminated glass and aluminum alloy profiles of hidden and semi hidden frame curtain wall glass. When using glass coating for full glass building curtain walls and point supported building curtain walls, acid-base silicone sealant cannot be used for bonding. Silicone type is generally used for weather resistant adhesives, as silicone structural adhesives have properties such as weather resistance, oxygen resistance, reactive oxygen species resistance, UV resistance, and high and low temperature resistance.

2. Norms implemented

The performance of neutral silicone structural sealant and acid-base silicone structural sealant used for building curtain walls should comply with the requirements of the current industry standard "Silicone Structural Adhesive for Building" GB-16776. GB-16776 is a mandatory industry standard that specifies that the service life of silicone structural sealant for metal curtain walls should not be less than 25 years. Compared to previous regulations in various countries around the world, it is more scientifically researched and rigorous, providing safety precautions for metal curtain walls.

3. Experimental verification

Before the application of silicone sealant, a nationally recognized testing center should conduct compatibility and detachment tests on the raw materials in contact with each other. Aluminum alloy materials should undergo surface anodizing treatment, electrophoretic principle painting, electrostatic powder spraying, or fluorocarbon spraying to solve the problem. When using organic coatings to solve the surface of aluminum alloy profiles, the construction records of the silicone structural adhesive topcoat should be checked to improve adhesion and reliability.

4. Key properties of silicone structural adhesive

Adhesive properties: defined as the bonding performance of sealant on a given substrate. Adhesive bonding relies on page physics adsorption, ion bond conversion, and mechanical equipment teeth biting to maintain connection. Excellent adhesion is the foundation for ensuring that the sealant maintains its function. Conduct adhesion tests between silicone structural adhesive and specific engineering project substrates.

Compatibility: defined as the performance of a sealant that does not cause adverse physical reactions between the surface of the sealant and other raw materials. Other raw materials generally refer to foam plastic rod, foam double-sided rubber, vulcanized rubber strip and other backing raw materials. Compliance with compatibility standards is fundamental to ensuring that the sealant maintains its own performance. Perform compatibility experiments on silicone structural adhesive and assembly line system software using annotations.

Usage period: defined as the time personally experienced from the time the sealant is placed in the joint until its effect is ineffective. It is immediately related to the tensile bonding performance after high and low temperature tests, immersion, and exposure to ultraviolet light and sunlight. The standard only requires a small value for distinguishing the compressive strength of the adhesive after the maintenance time of each brittle standard. However, based on relevant work experience and the judgment method of the European standard base, the ratio of the compressive strength after brittleness to the compressive strength under standard conditions, that is, the compressive strength maintenance rate, should be calculated. The larger the ratio, the better.

The performance of adhesive joints: Due to the design concept of large, medium, and extra large building structures, the service life is often between 50-100 years, with some exceeding 100 years. This stipulates that the service life of the building curtain wall with external scaffolding structure shall not be less than the service life of the building. In addressing issues such as anti-corrosion of embedded iron components, fatigue resistance of aluminum alloy profiles, thermal erosion of metal structures, and the performance and lifespan of laminated glass, design concepts and users are of utmost concern. Because the silicon oxygen bond in SiO2 is very stable, it determines its high-quality performance at the organic chemical structure level.

5. Basic regulations for engineering construction

The building curtain wall is produced and processed in a production workshop with enclosure structure, and has measures such as fire safety, explosion prevention, and pollution prevention. In addition, daily inspections of the symmetry, initial setting, and dry curing level of silicone structural adhesive shall be carried out in accordance with relevant standards. The natural environment for engineering construction should be carried out under a cleaning standard of 10-40 degrees Celsius and air humidity of 40% -80%. The construction team must understand the construction technology of weather resistant adhesive, grasp the required adhesive sealing position and the raw material situation of supporting facilities in the construction drawings. Using commonly used tools, single component weather resistant adhesive can be extruded using manual or pneumatic glue guns. The component weather resistant adhesive is repaired using a specialized adhesive mixing equipment.

6. Actual operational level of engineering construction

Eliminate oil stains, dust, surface damage, and loose air oxidation film on the surface of the substrate during the entire production, manufacturing, and transportation process, roughen the surface of the substrate, produce a surface shape suitable for tissue interlocking effects, and improve the organic chemical properties of the surface to enhance its performance under environmental hazards. Cleaning organic solvents are generally isopropanol, methyl ethyl ketone, and xylene. The cleaning cloth should be a pure cotton cloth that is milky white, clean, soft, and does not remove hair.

The cleaning of the substrate surface is carried out using the "double cloth scrubbing" method, which is moistened and cleaned with organic solvents. The scrubbing of the substrate surface can only be carried out in one direction. Before the organic solvent evaporates, immediately wipe off the organic solvent on the surface of the substrate with a second dry surface cleaning cloth.

To ensure the safety of building curtain walls, silicone structural adhesive cannot be ignored. This is some professional knowledge related to silicone structural adhesive that has been sorted out by the website editor. If you have a large amount of more technical, professional and comprehensive professional knowledge, please leave a message on the message board to inform the website editor. Afterwards, we will provide you with a large amount of professional knowledge related to the construction curtain wall manufacturing industry that you want to master from time to time. We look forward to your continuous care and support for the construction curtain wall industry.