At present, the widely used intermediate film for laminated glass in glass curtain walls is polyvinyl butyral, abbreviated as PVB. PVB
It has been used for many years and is widely familiar to the curtain wall industry. However, this type of adhesive film was originally designed for automotive glass
Developed, its performance is mainly to meet the following requirements for automotive glass:
1. It can reliably bond glass, reduce the scattering of broken glass, and maximize the safety of drivers and passengers.
2. It can prevent stones and other small objects from penetrating the glass and entering the car.
3. It has a certain degree of softness to prevent the driver's head from violently hitting the windshield and prevent personnel from flying out of the car
4. Meet the functional requirements of the car, including optics, noise reduction, and UV blocking.
Due to the fact that PVB laminated film is not primarily developed for building curtain walls, it is elastic, relatively soft, and shear resistant
The modulus is small, and there will be significant relative slip between two pieces of glass under stress. The bearing capacity is small, and the bending deformation is large. PVB interlayer
Glass can be used for general glass curtain walls, but is not suitable for glass curtain walls with high performance requirements.
At the same time, the exposed edges of PVB laminated glass are prone to moisture and glue opening, and PVB film laminated glass can be used for a long time before it can be damaged
It is prone to yellowing and discoloration, which should be noted.
The ideal laminated glass intermediate membrane for building curtain walls should meet the following requirements:
1. It has high bonding ability to glass, strong tear resistance, and can prevent glass from flying when broken.
2. Has strong protective capabilities that can prevent damage from natural forces and manpower. Against strong winds, earthquakes, violence, theft
Thief and others have sufficient resistance.
3. Can withstand sudden impacts from indoor personnel, prevent glass from flying or falling out as a whole, and prevent indoor personnel from falling out
4. There is sufficient residual bearing capacity, and the glass will not fall off as a whole when it undergoes bending deformation after being broken.
5. The intermediate film has a large shear modulus, which allows the two pieces of glass to work as fully as possible under bending, thereby improving the glass's strength
Bearing capacity and bending stiffness, reducing the thickness of glass and reducing its self weight.
6. Colorless and transparent, able to withstand ultraviolet radiation, water vapor, and external climate changes, and does not turn yellow or discolor after long-term use.
The PVB adhesive film currently used cannot fully meet the above requirements. It is necessary to develop high-performance curtain wall interlayer
Glass specialized intermediate film to adapt to high-rise building curtain walls, large-span daylighting roofs, oversized laminated glass, and all glass
High standard requirements for laminated glass in terms of structure.