How to Avoid Cracking of Silicone Sealant?

Usually, we may have heard more or less about some news about silicone adhesive cracking, sometimes it is the middle of the adhesive cracking, sometimes it is the two sides cracking, and sometimes it is the middle and both sides cracking at the same time, do not know the specific reason for the cracking is very troubling.

When the silicone sealant is fully cured for a period of time, there may be cracking problems due to its own or external forces, which directly affects the bonding and sealing effect of the sealant. Adhesive ability and sealing is very important for the use of silicone adhesive effect, under normal circumstances, sealant cracking has three states, in the middle of the crack cohesion damage, the two ends of the adhesive surface split bonding damage and the mixed damage of the two.

1. Causes of silicone sealant cracking

1)The joint design is unreasonable, such as the glue seam is too narrow, the sizing is difficult; Or the sizing process is not standardized, the bonding and sealing are not in place.

2) Improper selection of sealant, displacement ability can not meet the requirements of the use of joint displacement.

3) The actual plate size installation deviation is too large.

4) Sealant pre-curing process shrinkage is serious, joint deformation is too large, joint displacement.

5) Three-sided bonding, resulting in limited displacement capacity of sealant.

6) The sizing thickness does not meet the requirements of the specification, too thin or uneven thickness, resulting in damage or bond damage during use.

7) The construction of the ambient temperature is too high or too low, curing by external tensile force, so that the colloidal cracking, can not form a round rubber layer.

8) The sealant is not used within the validity period.

2. So how should you avoid colloid cracking?

1) In the construction must be familiar with the relevant construction substrate and substrate compatibility issues, starting from the construction purpose, goal, choose big brands and other good quality reputation, quality guaranteed silicone sealant.

2) Before construction, take a small number of samples to do a compatibility test before construction, verify whether the compatibility between the sealant and the substrate is good, and the bonding and sealing effect of the sample.

3) Before construction, the base material should be cleaned and water removed before construction. The base material should be dry and clean. Ensure that the sealant can be well bonded to the substrate.

4) After sizing to ensure that the construction site has a good temperature and humidity environment, and to ensure a good maintenance environment and sufficient maintenance time in the later period.