Where should polyurethane sealant be used?

Polyurethane sealant is not used casually, it has a specific place of use, generally this glue is used in the structural assembly part, the joint part of the building curtain and the stone panel, so when using this gel, we must first understand the use of the location.

First, structural 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 must not be allowed to fall off, and must meet the requirements of national mandatory standards. 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. This adhesive has high tensile strength and elongation at break, and can withstand greater loads with the same bonding width.

Second, the joint part of the building curtain panel. 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. It 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, but also has a good elastic recovery rate, after the displacement of the panel disappears, it can return to the original state.

Three, stone panel parts. Special stone silicone sealant must be used for 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. There are two types of glue. First, the stone sealant is used for sealing the joint between the stone plates. The second is the glue used for dry hanging stone, which is used for bonding between stone and metal hooks. In the past, rigid epoxy tree stone dry hanging glue was commonly used, and when the building shook, the stress was also transmitted to the stone panel, and the stone was easy to be cracked by the earthquake.

Fourth, the top of the lighting. 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. Its displacement capacity is plus or minus 50%. Lighting top glue also requires good transparency, beautiful and generous.

Five, 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 a sealant that can be cured at room temperature. When fully cured, a whole is formed between the glass and the aluminum alloy. In the past, it was filled with polyacrylate, neoprene glue, polyurethane, etc., which was either easily destroyed after external force, or volatilized harmful gases. Silicone sealant has no such drawbacks and can play a long-term sealing and waterproof role.