As a crucial component of modern architecture, the type of glass used for a glass curtain wall directly impacts the building's safety, aesthetics, and energy efficiency. Laminated glass, which is made by sandwiching a transparent polymer film between two glass panes, maintains its structural integrity even when broken. It also offers excellent sound insulation, heat resistance, and fire-retardant properties. In curtain walls, laminated glass enhances safety by preventing dangerous shards from scattering upon impact.

Laminated glass is a composite material made by bonding two or more glass panes with an interlayer. Its primary functions are to improve safety, soundproofing, and durability. PVB laminated glass, which uses a polyvinyl butyral (PVB) film as the interlayer, is a major type of laminated glass widely used in architectural curtain walls, automotive glass, and photovoltaic modules. The term "laminated glass for curtain walls" refers to the specific application of laminated glass in this context. Besides PVB, other interlayer materials like SGP (ionoplast interlayer) are also used.

(1) Safety: The Foundational Guarantee of PVB Film

The safety of PVB laminated glass is its core advantage for curtain wall applications. When the glass shatters from an external impact, the high adhesion of the PVB film firmly holds the fragments together, preventing them from flying and causing injury. This property meets the safety requirements for curtain walls, which must be "fall-proof and anti-fragmentation." Although SGP film has 5 times the puncture resistance and 100 times the stiffness of PVB, PVB film offers better ductility, is easier to bond with glass at room temperature, and is more cost-effective. This makes it suitable for conventional curtain walls, while SGP is typically reserved for high-strength applications like skyscrapers and large-span structures.

(2) Functionality: The Combined Advantages of Sound Insulation, Heat Insulation, and UV Protection

1. Sound Insulation Performance

PVB film has excellent sound-damping properties that effectively reduce the transmission of high-frequency noise (such as traffic and equipment noise), creating a quieter environment inside the curtain wall. Test data shows that curtain walls using PVB laminated glass can reduce noise by 25-35 dB, outperforming ordinary insulated glass units.

2. Heat Insulation and Energy Efficiency

PVB film, by introducing nano-scale heat-insulating media into its molecular structure, effectively blocks infrared radiation from sunlight. This property allows PVB laminated glass to significantly lower indoor temperatures in the summer, reducing the frequency and energy consumption of air conditioning. According to relevant data, the infrared rejection rate of PVB film can reach 95%-99%, meaning most infrared radiation is blocked from entering, which enhances indoor comfort and achieves energy-saving effects. The heat insulation performance of PVB film not only improves the comfort of living and working environments but also significantly reduces a building's energy consumption. Studies show that buildings using PVB laminated glass can reduce cooling energy consumption by 15%-20%, a substantial saving for large commercial buildings and residential towers.

3. UV Protection

The UV protection of PVB film primarily relies on its material structure and special additives. The PVB molecular chain contains a large number of polar groups that effectively absorb UV energy. During production, UV absorbers (such as benzotriazole compounds) are typically added to further enhance their UV-blocking effect. When PVB film is sandwiched between two glass panes to form laminated glass, the UV penetration path is blocked, and most of the UV radiation is absorbed or reflected by the film, preventing it from entering the indoor space. PVB film can absorb over 99% of UV rays, protecting furniture, textiles, and other interior materials from fading and ageing and extending their lifespan.

(3) Durability and Stability: Long-Term Reliability

1. Adhesion and Anti-Ageing

PVB film has excellent adhesion to glass. The hydroxyl groups (OH) in the PVB film form chemical bonds with the oxygen atoms (O) on the glass surface, creating stable intermolecular forces that are the primary source of bonding strength. During the heat pressing process, the softened PVB film fills the microscopic voids on the glass surface, and mechanical interlocking enhances the interfacial bond. At the same time, the electronic exchange between the film and water molecules on the glass surface further improves bonding stability. This composite bonding mechanism makes the interfacial bond strength of PVB film with glass significantly higher than that of ordinary films, becoming a key guarantee for the safety of laminated glass. It does not delaminate easily within a temperature range of -40°C to +70°C, making it suitable for long-term use in various climates. Its chemical stability also allows it to resist erosion from rain and pollutants, preventing mould growth on the glass edges or yellowing of the film.

2. Processing and Adaptability

PVB film can be cut and bent, adapting to the irregular designs of curtain walls (such as curved or bent glass). It is also highly compatible with other glass types, such as tempered glass and Low-E glass, to meet the curtain wall's requirements for light transmission and aesthetic design.

(4) Environmental and Sustainability

PVB film is a non-toxic, harmless, and environmentally friendly material. Waste laminated glass can be recycled and reused, meeting the "green building material" requirements for curtain wall projects. Compared to traditional curtain wall glass, PVB laminated glass has a recycling rate of over 85%, which reduces the environmental impact of construction waste.

With its high safety, multi-functional properties, and controllable cost, PVB laminated glass has become a mainstream choice for glass curtain walls. Its comprehensive performance in sound insulation, heat insulation, and UV protection meets the basic needs of most building curtain walls. The flexible adjustment of film thickness (≥0.38mm) and its processing adaptability further expand its range of applications.

Compared to high-end films like SGP, PVB laminated glass offers better cost-effectiveness for conventional scenarios. Compared to ordinary curtain wall glass, PVB laminated glass significantly reduces long-term maintenance costs due to its enhanced safety and durability. Therefore, in curtain wall design, PVB laminated glass is the ideal choice for a multi-faceted balance of "safety, function, environmental friendliness, and cost-effectiveness," making it especially suitable for conventional applications like mid-to-high-rise residential buildings and commercial complexes.