Selection of secondary sealant for insulating glass

An energy-saving glass for buildings such as residences, which has excellent thermal insulation and sound insulation performance, and is beautiful and practical. Sealant for insulating glass does not account for a high proportion of the cost of insulating glass, but it is very important for the durability and safe application of insulating glass, so how to choose it?

About insulating glass

Insulating glass is made of two (or more) pieces of glass and spacers bonded together. The sealing type mainly adopts the glue strip method and the glue joint method. At present, the double seal in the glue joint sealing structure is mostly used. The structure is as shown in the figure: two pieces of glass are separated by spacers, the spacer and the glass are sealed with butyl glue in the front, and the interior of the spacer is filled with molecular sieve, and the glass edge and the outside of the spacer are formed. The gap is sealed with a secondary sealant.

Types of secondary sealants for insulating glass

There are three main types of insulating glass secondary sealants: silicone, polyurethane and polysulfide. However, due to polysulfide, polyurethane adhesive has poor UV aging resistance, and if the bonding surface with glass is exposed to sunlight for a long time, degumming will occur. If the phenomenon occurs, the outer sheet of the insulating glass of the hidden frame glass curtain wall will fall off or the sealing of the insulating glass of the point-supported glass curtain wall will fail. The molecular structure of the silicone sealant makes the silicone sealant have the advantages of excellent high and low temperature resistance, weather resistance and ultraviolet aging resistance, and at the same time, the water absorption rate is low, so silicone is mainly used in the market.

Hazards of Improper Application

The problems caused by the improper selection of the secondary sealant can be divided into the following two categories: one is the loss of the use function of the insulating glass, that is, the original function of the insulating glass is lost; the other is related to the safety of the application of the insulating glass— — That is, the safety hazard caused by the falling of the insulating glass outer sheet.

The reasons for the failure of insulating glass seals are usually:

In the identification of curtain wall quality accidents, it is found through analysis that there are three main reasons for the falling of outer glass:

1.The compatibility of the insulating glass secondary sealant;

2.In order to save costs, the relevant parties blindly pursue low prices, and the secondary sealant for insulating glass uses non-silicone structural sealants such as polysulfide and silicone construction sealants;

3.Some construction workers are unprofessional and not rigorous, resulting in the problem of the injection width of the insulating glass secondary sealant.

Precautions for the selection of secondary sealant

The secondary sealant for insulating glass has a great influence on the quality and service life of insulating glass. The structural sealant for insulating glass is even directly related to the safety of the curtain wall. Therefore, we must not only choose the right product, but also choose the right product.

First, it’s standards-compliant and on-demand. Second, do not use oil-filled sealants. Finally, choose a reputable brand such as junbond