How to choose silicone sealant for different construction parts?

Silicone sealant is a kind of polydimethylsiloxane as the main raw material, easily extruded under most temperature conditions, and cured with moisture in the air into excellent, durable high modulus, high elasticity silicone rubber.Silicone sealant has a single component, two components, and structural glue, weather resistant glue, etc. Different silicone sealant should be selected for different construction parts:

1. Structure assembly parts

The sealant used between the curtain wall panel and its supporting structure needs to withstand a variety of loads, and ensure long-term adhesion, and is not allowed to fall off, and must meet the requirements of the national mandatory standard "silicone structural sealant for construction" (GB16776).

Especially in high-rise and super high-rise curtain walls, large partition glass curtain walls, curtain walls using laminated insulating glass, curtain walls in seismic 9 degree fortified areas, and even in the combination of these situations, it is more necessary to use high performance silicone structural sealant. Because the tensile strength and elongation at break of this glue are high, with the same bonding width can withstand greater loads.

2. Building curtain panel joint parts

The expansion joint between the curtain wall panel and the panel needs to be filled with glue, and silicone weather resistant sealant should be used. Because this environment silicone sealant needs to withstand the displacement caused by wind load, dynamic load, thermal expansion and contraction of the substrate deformation, in the case of stretching or compression, the cohesiveness will not be destroyed, there is a good elastic recovery rate, after the displacement of the panel disappears, it can return to the original state.

3. Stone panel parts

Special stone silicone sealant shall be used for the stone panel components. Because the stone itself is a porous material, it is vulnerable to pollution, and it is difficult to remove after pollution. The general sealant contains non-reactive low molecular substances such as plasticizers, which will migrate from the inside of the glue to the inside of the stone, and oil and dust will appear on the surface of the stone, causing stone pollution.

4. Lighting top position

Due to its own weight load, snow load, wind load, asymmetric load and material thermal expansion and contraction caused by large and complex displacement, not only horizontal displacement, but also shear displacement. Especially when using polycarbonate plate, due to its high coefficient of thermal expansion and contraction, it is six or seven times that of glass.

This requires that the sealant has a low modulus, high displacement capacity, has good material properties, can be freely telescopic, it is best to use 50LM(50 low modulus) silicone sealant, displacement capacity of plus or minus 50%. In addition, lighting top glue also requires good transparency, beautiful and generous.

5. The parts between doors and windows

The gap between the aluminum alloy and the glass of the colored aluminum alloy doors and Windows should be filled with special adhesive for aluminum alloy doors and Windows. When fully cured, the glass can form a whole with the aluminum alloy.

In the past, aluminum alloy doors and Windows were commonly filled with polyacrylates, neoprene glue, polyurethane, etc., which were either easily damaged by external force or volatile harmful gases. The special adhesive for aluminum alloy doors and Windows has no such drawbacks, and can play a long-term sealing and waterproof role.