The Impact of Low Winter Temperatures on Silicone Structural Sealants: Common Issues and Solutions
Slower Curing Speed
Issue: In low-temperature conditions, the curing speed of silicone structural sealants slows significantly. For single-component sealants, curing depends on environmental temperature and humidity; lower temperatures and humidity levels result in slower curing. This delay becomes particularly noticeable at temperatures below 15°C.
Solution: Before application in cold environments, conduct a small-scale trial and test adhesion to ensure the sealant cures and adheres properly. If the temperature is below 4°C, it is generally not recommended to proceed with application. In factory settings, improving the operating environment's temperature and humidity can enhance the curing performance.
Reduced Adhesion Performance
Issue: Low-temperature and low-humidity environments can reduce the adhesion of sealants to substrates. The ideal operating environment for silicone sealants is typically a temperature range of 10°C to 40°C and a humidity range of 40% to 80%. At lower temperatures, the sealant's wetting ability on the substrate surface decreases, and invisible condensation or frost may form, affecting adhesion.
Solution: When the operating temperature is below 10°C, perform adhesion tests in the actual construction environment before proceeding. For factory operations, increasing the temperature and humidity of the workspace can accelerate curing and ensure optimal adhesion. Additionally, extend the curing time as needed.
Thickening of Sealant and Reduced Flowability
Issue: At low temperatures, the sealant thickens and becomes less flowable. For two-component sealants, this thickening increases the pressure required by application equipment. For single-component sealants, extrusion requires more force, reducing operational efficiency.
Solution: If the thickening does not significantly impact construction, no special measures are needed. If operational efficiency is affected, consider raising the storage temperature of the sealant or placing it in a warmer environment before use. Additionally, select high-thrust tools, such as pneumatic or electric guns, to facilitate smoother extrusion.