Laminated glass is a commonly used glass in the field of architectural glass, which is also known as peace glass. Laminated glass is composed of multiple layers of glass, in addition to the glass, the rest is the sandwich in the middle of the glass, usually there are three kinds of sandwich: EVA, PVB, SGP.
PVB sandwich Trust is one of the more familiar names. PVB is also a common sandwich material used in architectural glass and automotive glass at present.
The storage process and processing method of PVB interlayer are more complex than EVA, and the requirements for temperature and humidity are higher. PVB processing request temperature control between 18℃-23℃, relative humidity control at 18-23%, PVB adhere to 0.4%-0.6% moisture content, after preheating rolling or vacuum process is the use of autoclade to stop heat preservation and pressure, autoclade temperature: 120-130℃, pressure: 1.0-1.3MPa, time: 30-60min. PVB consumer equipment needs about 1 million funds, and there is a certain difficulty for small businesses. In a few years ago, mainly to foreign Dupont, Shou Nuo, water and other manufacturers consumption, domestic PVB is mainly recycled data to stop secondary processing, but the quality stability is not very good. In recent years, domestic PVB consumer manufacturers are also gradually developing.
PVB has good safety, sound insulation, transparency and chemical radiation resistance, but PVB water resistance is not good, and it is easy to open in a humid environment for a long time.
EVA stands for ethylene-vinyl acetate copolymer. Because of its strong water resistance and corrosion resistance, it is widely used in packaging film, functional shed film, foam shoe material, hot melt adhesive, wire and cable and toys, etc., China usually uses EVA as sole information.
EVA is also used as the sandwich of laminated glass, and its cost performance is high. Compared with PVB and SGP, EVA has better activity and lower ablation temperature, and can be processed when the temperature reaches about 110℃. Its full set of consumer equipment needs about 100,000 yuan.
The film of EVA has good activity, which can stop the process of wire clamping and rolling in the film layer to create beautiful decorative glass with patterns and patterns. EVA has good water resistance, but it is resistant to chemical rays, and long-term sun exposure is easy to yellow and black, so it is mainly used for indoor partition.
SGP stands for ionic intermediate membrane (Sentryglass Plus), which is a high-performance sandwich material developed by DuPont. Its high performance is manifested in:
1, excellent mechanical properties, high strength. Under the same thickness, the bearing capacity of SGP sandwich is twice that of PVB. Under the same load and thickness, the bending deflection of SGP laminated glass is one quarter of that of PVB.
2. Tear strength. At the same thickness, the tearing strength of PVB adhesive film is 5 times that of PVB, and it can also be glued to the glass under the tearing condition, without making the whole glass drop.
3, strong stability, wet resistance. SGP film is colorless and transparent, after long-term sun and rain, resistant to chemical rays, not easy to yellow, yellowing coefficient < 1.5, but the yellowing coefficient of PVB sandwich film is 6~12. Therefore, SGP is the darling of ultra-white laminated glass.
Although the consumption process of SGP is close to that of PVB, the terminal price is high, so the application in China is not very common, and the awareness of it is low.
Post time: Aug-09-2024
