Insulating glass secondary sealant, did you choose the right one?

In the energy consumption of buildings, the energy consumption caused by glass doors and windows accounts for about 50% of the total energy consumption of buildings. As an important part of glass doors and windows, glass has the largest heat conduction and radiation area of external windows. Therefore, improving the energy-saving performance of glass has become the key to realizing building energy-saving. Insulating glass has become the first choice for people because of its excellent energy saving.

Insulating glass structure, the first seal adopts hot melt butyl glue to ensure low water vapor permeability of the insulating glass; the second sealant is used to ensure the structural integrity of the insulating glass unit, and the optional sealant includes silicone Sealants, polysulfide sealants and polyurethane sealants.

However, if it is a unit for structural assembly, a silicone structural sealant must be used.

Why do you say so?

Silicone sealant has the advantages of wide operating temperature range, low shrinkage and water absorption after curing, excellent aging resistance and wide operating temperature range, etc. It is currently the most widely used secondary sealant for insulating glass.

In the actual situation, the insulating glass often appears fogging, blurred vision, and tears when the butyl glue dissolves.

, water ingress and even the falling of the insulating glass outer sheet.

The reason is that in order to reduce costs, some silicone rubber manufacturers unilaterally pursue short-term interests and add a large amount of "white oil" to insulating glass sealants. The white oil will gradually volatilize over time, causing the colloid itself to harden and the surface gloss to be dull. What's more, the white oil will penetrate into the first hot-melt butyl sealant, causing the butyl rubber to swell and flow, resulting in the phenomenon of "tears" of the insulating glass.

The national standard "GB/T 11944-2012 Insulating Glass" clearly states that the quality of various materials used to make insulating glass is closely related to the service life of insulating glass, and the service life of insulating glass produced in accordance with standard specifications is generally not less than 15 years. . The quality of the edge sealing system determines the service life of the insulating glass.

Due to the relatively large price fluctuations of the main raw materials of silicone sealants in recent years, MS hollow glue has begun to appear on the market, which is known as "silicone sealant", but its product price is much lower than the market price of silicone sealant. Although MS glue has good aging resistance, good adhesion to a variety of building materials commonly used, low VOC, good environmental performance and surface paintability, it is widely used in prefabricated buildings and interior decoration. We evaluated the MS hollow adhesive, which itself has poor anti-ultraviolet aging performance for glass bonding, and will have debonding problems after working outdoors for a period of time.

Therefore, MS glue cannot be used for secondary sealing of insulating glass.

To sum up, in the process of manufacturing insulating glass, we should first select different types of sealants for the application parts, and secondly, we must ensure that the selected sealants meet the corresponding standards and are of excellent quality; in addition, the sealants must also be produced in advance. Compatibility and adhesion testing of the products, and following the standard construction process can ensure the quality of the produced insulating glass, and ultimately make the building more energy-saving and environmentally friendly.