Basic classification and core selection factors of sealants
Basic classification and core selection factors of sealants
The performance differences of sealants are due to the chemical matrix. Silicone glue (moisture curing) has the best weather resistance (applicable to -50℃~250℃) and ±50% displacement capacity, but it is easy to contaminate the substrate; polyurethane glue (reaction curing) has a bonding strength of 2.5MPa, outstanding oil resistance but afraid of moisture; polysulfide glue is suitable for fuel tank sealing due to its fuel resistance; acrylic glue (solvent evaporation) is cheap but has poor elasticity (displacement capacity is only ±7.5%); butyl glue (hot melt) has the best air tightness and is used for insulating glass sealing.
Key parameter comparison table
Type Modulus grade Displacement capacity Applicable substrate
Silicone glue Low-medium ±25~50% Glass/ceramic/metal
Polyurethane glue Medium-high ±25% Concrete/ABS plastic
Polysulfide glue High ±15% Steel/fuel pipeline
Avoidance tips: Neutral curing silicone glue must be used for concrete joints to avoid debonding caused by alkaline environment.
