Early laminated glass was generally produced by PVB film. PVB film was originally developed for automotive glass rather than for the building curtain wall industry. Although PVB film has been widely used for many years in the construction industry and gets good performance, it is not suitable for high-performance glass curtain walls due to the features of PVB film as follows:
Flexibility, softness and small shear modulus
The two glass sheets will have relative slip after being stressed and then it makes less load capacity and larger bending deformation
The SGP (SentryGlas® interlayer) is 5 times stronger and up to 100 times stiffer than PVB films. Besides its strength, SGP retains its clarity – even after years of service.
Comparing with laminated glass with PVB film, the performance of SGP laminated glass is superior:
1. SGP laminated glass has a high bonding ability to glass and strong tear strength, which can prevent the glass from breaking and scattering.
2. SGP laminated glass has a strong protective ability which can prevent natural disasters and human damage, and it has sufficient resistance to hurricane, earthquakes, violence, theft, etc.
3. It can withstand the sudden impact, which can prevent the glass from shattering or the whole out and avoid people and articles flying out and falling.
4. It will stay standing when both sides are broken. PVB laminated glass will fall down or breaks when both sides have become damaged.
5. It can either bear greater loads or – at the same load – can be reduced in glass thickness without compromising safety.
6. It is much less vulnerable to moisture exposure or yellowing over time.