Analysis of common problems in construction of silicone structural sealant

2020-01-13 14:45:32

1、 The curing of silicone structural sealant is slow.

According to many years of technical service experience, most of the reasons are as follows:

① The curing speed is slow due to low ambient temperature and humidity. Solution: improve the use environment and maintenance environment temperature, such as the use of closed space heating, air conditioning heating and other methods to maintain the maintenance environment temperature at 10-40 ℃, humidity at 50-90%;

② The curing speed is slow due to low temperature and humidity. Solution: confirm whether the proportion of component A and component B is normal by breaking time, and increase the proportion of component B to accelerate the curing speed within the range allowed by the manufacturer.

③ The silicone structural adhesive has expired or has its own quality problems. Solution: check the production batch number of glue, confirm whether the glue is within the warranty period, and select silicone structural glue with guaranteed quality and brand.

2、 Insufficient bonding width of structural adhesive: the actual width is less than the design width.

There are two main reasons for the insufficient bonding width of structural adhesive:

① The glue injection is not full. Solution: the glue injection is continuous and even, and the glue nozzle can extend into the joint at least half of the depth. After the glue injection, it shall be repaired.

② The joint assembly size is too small. Solution: assemble the joint in strict accordance with the design size of the glue joint.

3、 The structural colloid has bubbles or holes.

There are two main reasons for the bubbles and holes in structural colloids

① The glue injection is not full. Solution: same as above.

② When the dispenser is mixed with air, dense bubbles appear in the colloid. Solution: ensure that the dispenser is free of faults, and exhaust the air before use after barrel change.

All of the above problems are seriously harmful to the safe application of structural adhesives. During the construction, it is necessary to ensure that the bonding size of structural adhesive meets the design requirements, and the glue injection is full without bubbles and holes. It is hoped that the customers should avoid these problems in the process of using glue to ensure the safety of curtain wall.

Silicone structural sealant is very important to the quality and safety of the curtain wall. Choosing "good glue" is the premise to ensure the quality and safety, and using "good glue" is an important process to realize the safe application of hidden frame curtain wall.

Glue machine:

The gluing machine is a kind of automatic equipment which controls and drips the coating such as adhesive, etc. It uses compressed air to send the coating to the rubber hose, and then through the program control, the coating is dripped or coated according to the preset path.

Working principle: compressed air is sent into the rubber bottle (syringe), and the rubber is pressed into the feed pipe connected with the piston chamber. When the piston is in the up stroke, the piston chamber is filled with rubber. When the piston pushes the rubber dropping needle downward, the rubber is pressed out from the needle mouth. The amount of glue dripped is determined by the distance of piston down stroke, which can be adjusted manually or controlled in software.