It is reported that the building structure silicone adhesive is generally used in the temperature range of 5~40℃. When the surface temperature of the substrate is too high (above 50℃), construction cannot be carried out. At this time, the construction may cause the curing reaction of the building sealant to be too fast, and the generated small molecular substances have no time to migrate out of the surface of the colloid, and gather inside the colloid to form bubbles, thereby destroying the surface appearance of the glue joint. If the temperature is too low, the curing speed of the building sealant will slow down, and the curing process will be significantly prolonged. During this process, the material may expand or contract due to temperature differences, and the extrusion of the sealant can distort the appearance.
When the temperature is lower than 4 ℃, the surface of the substrate is easy to condense, freeze and frost, which brings great hidden dangers to the bonding. However, if you take care to clean dew, icing, frost and master some details, building structural adhesives can also be used for normal gluing construction.
Cleaning of material surfaces is critical for sealing and bonding. Before bonding, the substrate must be cleaned with a solvent. However, the volatilization of the cleaning and leveling agent will take away a lot of water, which will make the surface temperature of the substrate lower than the surface temperature of the dry ring culture. In an environment with a lower drying temperature, it is easy to transfer the surrounding water to the substrate one by one It is difficult for some workers to notice the surface of the material. According to the normal situation, it is easy to cause the bonding failure and the separation of the sealant and the substrate. The way to avoid similar situations is to clean the substrate with a dry cloth in time after cleaning the substrate with a solvent. The condensed water will also be wiped dry by the rag, and it is better to apply glue in time.
When the thermal expansion and cold contraction displacement of the material due to temperature is too large, it is not suitable for construction. When building structural silicone sealant moves in one direction after curing, it can cause the sealant to remain in tension or compression, which can cause the sealant to move in one direction after curing.
Post time: May-20-2022