The initial dew/frost point is not clear, indicating that the residual moisture in the air layer of the insulating glass is saturated at -40°C. If the initial dew point of the insulating glass is also reached at higher temperatures, it is possible that there are gaps in the insulating glass sealing structure. This situation is more common on insulating glass made of composite adhesive strips.
The vacuum box test fails, indicating that there is a gap in the sealing of the insulating glass, so that the insulating glass does not deflect externally in a vacuum state. This situation mostly occurs in the case of poor labor quality.
When ultraviolet irradiation fails, an oil film formed by cooling of volatile organic surface gases appears on the inner glass wall of the insulating glass air layer. It means that the desiccant in the insulating glass cannot effectively adsorb the volatile organic solvent in the air layer. This situation is prone to appear on insulating glass made of polysulfide adhesive single-pass sealing and 3A or 4A molecular sieve desiccant.
The failure of the high temperature and high humidity test indicates that there is condensation in the air layer of the insulating glass, which is caused by the fact that the insulating glass adhesive sealant does not effectively prevent external moisture from entering the air layer of the insulating glass. This situation is prone to appear on insulating glass with polysulfide glue single-pass sealing.
The failure of the climate cycle test indicates that there is condensation in the air layer of the insulating glass, which is caused by the fact that the insulating glass adhesive sealant does not effectively prevent foreign moisture from entering the air layer of the insulating glass. This is often the case on insulating glass made of composite adhesive strips.
The above five testing contents are the mandatory testing items of China's national insulating glass testing. In addition, there are two foreign contents: argon retention rate and P1 detection.
Argon retention test, the obvious change before and after the argon retention rate test indicates that there is a gap in the sealing of the insulating glass, resulting in an increase in the dew point after the test. The test methods used in the specific test are the above-mentioned ultraviolet irradiation, high temperature and high humidity test, and gas cycle test.
P1 test, P1 test is an accelerated aging test to detect the sealing life of insulating glass. Test conditions: high temperature 60°C, continuous water spray and ultraviolet irradiation of 2500 microwatts per square centimeter. The use of different insulating glass (sealing) structures, reflected in the difference in sealing life is very obvious. Insulating glass with a short sealing life is more likely to occur in the case of a single-pass sealing structure (including a single-pass sealed composite adhesive strip).
The sealing failure of insulating glass may be manifested in one aspect of the above 7 items, or it may be several, or it may be all. For example, the formation of ultraviolet irradiation causes the formation of an oil film on the inner wall of the glass in the air layer after the volatilization and cooling of organic compounds, even if the seal of the insulating glass is intact, as long as the desiccant used does not match.
The sealing failure of the insulating glass is directly manifested in the condensation phenomenon in the air layer of the insulating glass. In the event of a sealing failure, a small gap occurs in which the inner glass wall in the air layer is saturated with dew (temperature greater than zero degrees Celsius) or frosted (temperature less than zero degrees Celsius) due to the desiccant. Over time, water accumulates in the air layer of insulating glass, eventually forming the "fish tank" phenomenon.