Analysis and Answers to Common Problems of Insulating Glass Seal Failure

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 (about 70% to 90% of the area of different types of 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, among which insulating glass has the best thermal insulation and energy-saving effect among several types of building energy-saving glass.

However, in practical cases, the failure of insulating glass is often encountered, such as glass breakage or sealing failure, among which more than 90% of insulating glass failures are caused by sealing failure. The main reasons for seal failure are unreasonable structural design, improper selection of sealant, improper construction and external environmental influence.

In many practical projects, it is found that the outer sheet of insulating glass falls off. The main reasons are as follows:

(1) The inferior silicone sealant or polysulfide sealant is selected, which will cause problems such as hardening and cracking after long-term use, causing the outer glass sheet to fall off;

(2) Improper control of sealant construction quality, uneven mixing of sealant leads to poor adhesion.

In view of the problem that the outer sheet of insulating glass falls off, the following points should be paid attention to:

①The bonding width of the second sealant should meet the design requirements of the sealant size in JGJ 102 "Technical Specifications for Glass Curtain Wall Engineering";

②The secondary sealant for insulating glass of hidden frame curtain wall, semi-hidden frame curtain wall and point-supported glass curtain wall must use silicone structural sealant;

③The secondary seal should be mixed and glued with a special gluer, and the construction process must be standardized.

The root cause of the fogging of insulating glass is that the water content in the hollow cavity increases, resulting in an increase in the dew point.

The main reasons are:

(1) The exposure time of molecular sieve is too long, resulting in saturation of molecular sieve with water absorption;

(2) Butyl rubber coating has broken glue and missing coating;

(3) The secondary sealant has uneven mixing and insufficient cleaning during the sizing process, resulting in seal failure;

(4) The movement of the secondary sealant without sufficient maintenance leads to dislocation failure;

(5) premature aging failure caused by inferior butyl rubber and secondary sealant.

In view of the fogging problem, in-depth management should be carried out in material selection and on-site construction process, so as to ensure the service life of insulating glass.

Improper selection of sealant is the cause of the "tears" phenomenon of insulating glass, which is manifested as follows:

(1) The secondary sealant filled with mineral oil will swell and flow down due to the massive migration of mineral oil;

(2) Too much low molecular weight base material is added to the inferior butyl rubber, resulting in a low softening point of the material and flowing in a high temperature environment.

Therefore, it is necessary to choose butyl rubber and secondary sealant with guaranteed product quality when hollowing together.

In the actual project, some problems were also found, and there were tears in the insulating glass in a few parts of the whole project. Analysis of the on-site problems found that the weather-resistant adhesive used at the edge during the installation of the insulating glass was an inferior sealant filled with a large amount of mineral oil. In order to solve the tearing problem of insulating glass, we also need to control the quality of the weather-resistant adhesive used in the project.

Laboratory testing of building systems, glue selection and construction procedures determine the performance of the entire product. Silicon Treasure Technology has developed insulating glass sealing supporting products, including butyl rubber products used in the first seal and silicone series products used in the second seal, and provides customers with a comprehensive "one-stop" pre-sale, in-sale, after-sale service and Solutions to ensure better use effect for customers.