PVB vs SGP vs EVA: Understanding the Interlayers Behind Laminated Glass

The choice between PVB (Polyvinyl Butyral), SGP (SentryGlas® Plus ionoplast), and EVA (Ethylene Vinyl Acetate) can significantly influence structural performance, acoustic control, durability, and specialised functionality.

At Tough Glass, these interlayer technologies underpin several key product ranges:

• ToughGuard® – PVB laminated safety glass

• ToughSound® – Acoustic PVB laminated glass

• ToughView® – Structural SGP laminated glass

• ToughSwitch® – EVA laminated combined with switchable interlayer.

Understanding where each interlayer excels helps ensure the right glass is specified for the right application.

What Is an Interlayer?

An interlayer is the polymer layer permanently bonded between two or more panes of glass during the lamination process.

Its primary role is safety. If the glass breaks, the fragments remain adhered to the interlayer rather than falling away.

However, modern interlayers do much more than hold broken glass together. Depending on the material selected, they can also improve:

• Acoustic performance

• Structural strength

• Impact resistance

• UV protection

• Weather durability

• Privacy technology integration

The performance characteristics vary considerably between PVB, SGP, and EVA.

PVB Interlayers: The Industry Standard

Polyvinyl Butyral (PVB) is the most widely used interlayer in architectural laminated glass.

For decades, it has been the preferred solution for safety glazing because it delivers reliable impact performance, optical clarity, and cost-effective manufacturing.

When glass breaks, the PVB layer holds fragments together, helping reduce the risk of injury and maintaining a barrier within the opening.

ToughGuard®: Everyday Safety Performance

ToughGuard® uses standard PVB interlayers to create laminated safety glass suitable for a wide range of residential and commercial applications.

Typical uses include:

• Shopfronts

• Framed Balustrades

• Doors and sidelights

• Schools

• Healthcare facilities

• Residential glazing

For most safety glazing applications, PVB remains the practical and economical choice.

Key Benefits

• Excellent safety performance

• Meets Australian laminated glass requirements

• Good optical clarity

• UV reduction

• Cost-effective specification

ToughSound®: Enhanced Acoustic Performance

While standard PVB delivers some sound attenuation, specialised acoustic PVB formulations are designed specifically to reduce noise transmission.

ToughSound® incorporates acoustic interlayers engineered to dampen sound vibrations more effectively than conventional laminated glass.

This makes it particularly valuable in environments affected by:

• Road traffic

• Rail corridors

• Aircraft noise

• Urban developments

• Commercial fit-outs requiring speech privacy

Key Benefits

• Improved acoustic insulation

• Maintains laminated safety performance

• Enhanced occupant comfort

• Ideal for noise-sensitive projects

SG Interlayers: Structural Strength Beyond Traditional Lamination

SG (SentryGlas®) is an ionoplast interlayer developed for applications where structural performance is critical.

Compared with standard PVB, SGP is significantly stiffer, stronger and water resistant. This allows the laminated glass assembly to behave more like a monolithic panel, even under high loads.

In breakage scenarios, SG retains considerably greater post-breakage integrity, helping the glass continue to perform after impact.

ToughView®: High-Performance Structural Laminated Glass

ToughView® is designed for projects where strength, rigidity, and transparency are equally important.

Applications commonly include:

• Frameless balustrades

• Glass floors

• Overhead glazing

• Structural glass fins

• High-performance facades

• Cyclonic and high-wind environments

Key Benefits

• Higher structural performance than PVB laminates

• Increased stiffness

• Improved edge stability

• Superior post-breakage behaviour

• Suitable for demanding engineering applications

EVA Interlayers: Built for Specialised Applications

EVA (Ethylene Vinyl Acetate) differs from both PVB and SGP because it is often selected for its compatibility with specialised laminated glass technologies.

One of the most important examples is switchable privacy glass.

ToughSwitch®: Switchable Privacy Glass

ToughSwitch® combines EVA interlayers with liquid crystal technology to create glass that can transition between transparent and opaque states at the touch of a button.

When powered, the glass remains clear.

When power is removed, the liquid crystal layer disperses light, creating privacy while still allowing daylight transmission.

Applications include:

• Corporate meeting rooms

• Healthcare environments

• Residential luxury bathrooms

• Hospitality spaces

• Executive offices

• Smart building projects

Why EVA Is Used

EVA provides strong adhesion and excellent compatibility with the specialist films required for switchable glass systems.

It also offers:

• Good moisture resistance

• Long-term optical stability

• Reliable bonding around embedded technologies

For products such as ToughSwitch®, EVA is less about structural strength and more about enabling advanced glass functionality.

Comparing PVB, SGP, and EVA

Which Interlayer Is Right for Your Project?

The best interlayer depends entirely on the performance requirements of the application.

Choose ToughGuard® when standard laminated safety performance is required.

Choose ToughSound® when noise reduction is a key project objective.

Choose ToughView® when structural strength, rigidity, or post-breakage performance are critical.

Choose ToughSwitch® when integrating smart privacy technology into the glazing design.

Rather than viewing one interlayer as "better" than another, it's more accurate to think of each as a specialised tool designed to solve a specific challenge.