there are only two cases of window glass life, humid air and high temperature. Continuous humid air can cause mildew of glass, but the rate of mildew of glass is very slow under normal temperature, which usually takes several months, in normal use environment, there is little humid air lasting for several months, so the glass will not mildew if exposed in the air. The mildew of glass usually occurs in the overlapping storage process of glass. The glass is prone to mildew in a damp warehouse or after air storage of rain. The sheet glass without tempering is more likely to mildew than tempered glass.
Life of tempered glass
physical tempering is to heat the glass and then chill, which changes the structure between molecules inside the glass; Chemical tempering is used to exchange the molecular structure of the glass surface under high temperature; both methods permanently change the microstructure of glass materials. Therefore, unless there is high temperature and strong chemical effect, the tempering characteristics will not decay or change with the change of time under normal use.
Life of hollow glass
hollow glass is a combination of glass substrate, spacer frame (aluminum strip), desiccant (molecular sieve), sealing material (butyl rubber, polysulfide adhesive or structural adhesive). In the composition of insulating glass, glass and aluminum frame are usually very stable, and the life of insulating glass depends on the life of molecular sieve and sealing material. Due to the change of ambient temperature, the gas in the hollow cavity is always in a state of expansion or compression, which makes the hollow glass sealing system always in a state of stress. At the same time, ultraviolet rays in the environment, both water and moisture will accelerate the aging of the sealing system, thus causing water vapor to accelerate into the hollow cavity. When a large amount of water vapor appears in the hollow glass cavity, the hollow glass will become invalid, and the failure of the hollow glass means that the service life of the hollow glass will end. The key to ensure that insulating glass does not fail is desiccant and sealing material.
As for the life of hollow glass, the earliest glass enterprises in China gave the concept of 10-year warranty period with reference to American standards; In the national standard GB/T11944-2012 for hollow glass, for the first time, the reference agreement is put forward for the life of insulating glass, and the concept of "The expected life of insulating glass should be greater than 15 years" is put forward. In fact, the service life of hollow glass is closely related to the selection and processing technology of hollow glass materials. At the same time, it is also affected by many factors such as hollow glass layout composition and use environment, which is difficult to be simply quantified. For the insulating glass that has been installed on the wall, the relatively simple measurement method is actually to measure the dew point or the air humidity of the spacer layer.
Low-E glass life
Low-E the life of glass mainly depends on the life of its hollow sealing system. We know that the main constituent materials of Low-E film are metal, alloy, metal oxide and metal nitride. Metal nitride is generally used as a protective layer in the film structure, and its performance is very stable. Metal oxide and gold layer are generally used as the dielectric layer in the film layer to connect the silver layer and the protective layer, and their properties are relatively stable. The silver layer in Low-E is relatively active, but its oxidation is conditional and requires water vapor. Therefore, as long as the insulating glass does not fail, there is basically no need to consider the life of the Low-E film layer separately.
Life of laminated glass
laminated glass is a composite glass product with two pieces of organic polymer intermediate film sandwiched between the glass, and after processing, the glass and the intermediate film are permanently bonded into one. The laminated glass will stick to the film even if the glass is broken, which effectively prevents the occurrence of debris injury and penetration fall, and ensures personal safety.
The service life of laminated glass mainly depends on the material of interlayer intermediate layer. Normally, wet laminated glass and EVA laminated glass are mainly used for indoor partition, and are not suitable for building doors and windows or curtain walls. Wet laminated glass will accelerate aging under sunlight, and yellow will appear 1-2 years later, and degumming bubbles, ice flowers and fog will appear one after another in 2-3 years. Generally speaking, the aging speed of wet laminated glass is much faster than EVA laminated glass. EVA laminated glass can have a life of more than 10 years when used indoors to avoid direct sunlight.
PVB and SGP laminated glass, which are usually used as doors and windows or curtain walls, have much better aging resistance. The most typical failure of laminated glass PVB and SGP is unglue. Unglue means that the glass and the spacer layer are disengaged, losing the safety characteristics of laminated glass. As for the life of PVB and SGP laminated glass, there are no relevant standards and specifications in China at present. At present, domestic glass processing enterprises generally refer to the relevant materials of foreign PVB and SGP suppliers to give a warranty period of 5-7 years.
In fact, the service life of PVB and SGP laminated glass is greatly influenced by the thickness of intermediate interlayer, the quality of laminated glass substrate and the control of laminated glass process, except by the material of intermediate layer.
