Cause analysis of cracking of door and window sealant

The reason for the crack of door and window sealant is the quality problem of door and window sealant, as follows

White oil precipitation

With the continuous precipitation of white oil for a long time, the joint colloid shrinks excessively, hardens, loses its replacement ability, and expands with heat and contracts with cold, which can not adapt to the displacement of the matrix, leading to cracking.

Poor resistance to joint displacement and cracking

Poor resistance to joint displacement and cracking.

Less crosslinking agent content

The content of cross-linking agent in the formula is small, which is not enough to make the sealant react to form a perfect cross-linking network structure, and there are structural defects, which easily lead to colloid cracking.

Use within the validity period

The sealant is not used within the validity period.

Uneven sizing thickness

Uneven sizing thickness easily leads to colloid cracking in thin areas.

The substrate surface temperature is too high or too low.

When the surface temperature of the substrate is too high or too low, the colloid is easy to crack after curing.