Sealant mainly includes two types of building sealant (weathering adhesive) and structural sealant (structural adhesive). They have many performance requirements that are similar, but architectural sealants (weather-resistant adhesives) emphasize the resistance to atmospheric changes, UV resistance, and aging resistance; while structural sealants (structural adhesives) are more important in strength, elongation, Mechanical properties such as bonding properties. Both should be selected according to the purpose of use.

1 The main performance of building sealant (weather-resistant adhesive) The architectural sealant (weather-resistant adhesive) for aluminum alloy glass curtain wall is mainly silicone sealant. The weather-resistant silicone sealant must be a one-component neutral glue, and the acid-alkaline glue cannot be used, otherwise the aluminum alloy and the structural silicone sealing tape will be adversely affected. The glue can react with water vapor in the air and gradually harden. Therefore, it should avoid contact with water during storage to avoid deterioration, but the glue can be adapted to sunlight, rain, ice, ice, ozone and high and low temperature after curing. Silicone sealant has a variety of colors, light-colored sealant has weak UV resistance, and is only suitable for indoor engineering. Aluminum alloy glass curtain wall caulking should be dark. According to the Technical Specification for Glass Curtain Wall Engineering (JGJ102-96), the performance of weather resistant silicone sealant should meet the requirements of Table 1.

2 The main performance of structural sealant (structural adhesive) The structural sealant (structural adhesive) for aluminum alloy glass curtain wall is mainly silicone sealant. Because it connects glass and glass, glass and aluminum, it bears wind, earthquake, self-weight and temperature changes, and plays an important structural role in the curtain wall, so it has high requirements on its mechanical properties. As a structural sealant, it should have two functions: (1) excellent sealing performance; (2) good tensile bonding property with the material to be bonded. The tensile strength of the dumbbell type can only reflect the function (1); the tensile strength is H type, and the functions (1) and (2) can be reflected, so only the H-type bond tensile strength can satisfy the structural silicone. The actual needs of the sealant. The structural silicone sealant is divided into two components and two components. According to the Technical Specification for Glass Curtain Wall Engineering (JG102-96), the performance of the structural silicone sealant should meet the requirements of Table 2.
3 Select several issues to be aware of when using architectural sealants (weather-resistant adhesives) and structural sealants (structural adhesives).

3.1 The two shall not substitute each other. In particular, structural adhesives should not be used as weathering adhesives. Although the structural adhesive is expensive and relatively advanced, the weathering adhesive is reduced to a large generation. However, the weathering adhesive is mainly used for exterior building sealing, and has higher requirements on weather resistance. This structural adhesive is difficult to perform.

3.2 Both must use neutral glue, should be used within the validity period, expired weathering rubber and structural adhesive should not be used.

3.3 Most of the weathering adhesives and structural adhesives currently used are imported, and a small number of domestically produced ones, whether imported or domestically produced, must hold national certificates and various performance test reports. When used in curtain wall projects, The secondary properties of the two rubbers shall also be tested in accordance with Tables 1 and 2.

3.4 For structural adhesives, in addition to various performance tests, compatibility tests with contact materials shall be made. The so-called compatibility means that when the structural adhesives are in contact with these materials, they only act as bonding and do not affect the bonding. Any chemical change in performance.

3.5 Which kind of glue is used in the construction, it should be determined according to the purpose and location, construction conditions, batch size and other factors for economic and technical comparison.