Glazing Technologies

IQ's Strengthening Interlayer vs PVB Interlayers

Laminated glass is comprised of two or more panes of glass bonded together using an interlayer.  Laminates in glass have various benefits from increased security to improved acoustic reduction. They are used in structural glass floors to increase the strength of the glass panel for a walk on load. They are used within frameless glass balustrades to create cantilevered glass structures that can take the required line load. They are used within windows to improve acoustic reduction and are used within glass doors to achieve security requirements. But what laminate is right for your project?

Interlayer Types

PVB Interlayers

A PVB (polyvinyl butyral) Interlayer is the most commonly used glass interlayer. It is a clear interlayer, available in a range of thicknesses, that can be used to increase the strength, safety or security of a glass construction.

Ionplast Interlayers

Ionoplast interlayers are high specification, high strength interlayers, also known as an SGP or SentryGlas interlayer. The material was first produced by DuPont and offers greater strength and rigidity over a basic PVB interlayer.

With a tear strength of 5x times greater than PVB and 100x the rigidity, these high performance strengthening interlayers are used on critical areas.

It also has added clarity and doesn’t discolour over time.

The Benefits of an Ionplast Interlayer

Post glass breakage, a glass unit laminated with an IQ’s Strengthening Interlayer has greater strength than standard PVB. It is able to hold a 3300kg load with minimal deflection as opposed to an equivalent PVB laminated unit which displaced dramatically after 400 seconds. A strengthening interlayer also has a tested tear strength of 50 MJ/m3 compared to a standard PVB interlayer of 10-15 MJ/m3.

This means that even post breakage, the laminated glass panel can still hold the weight of a human for over 1800 seconds ensuring that installations are safe and secure until a repair can occur.

Using a high-performance interlayer in the glass to improve the strength of the installation means that you can reduce the thickness of the glass used, making installations much thinner and slimmer than would previously be possible. IQ’s High-Performance Interlayer has an Ultimate Tensile Strength of 34.5 MPa versus a PVB interlayers strength of 20 MPa.

When integrated into structural glazing or an appropriate framing system the incorporation of IQ’s High-Performance interlayer can be used as a bomb blasted film laminated into the glass unit for high-security uses.

Interlayers for UV Fading

According to research by the International Window Film Association (IWFA) there are multiple factors that can cause fading on furniture, artwork and wood. These are:

• Ultraviolet light (40%)
• Visible light (25%)
• Solar gain and heat (25%)
• Artificial lighting and humidity (10%)

In addition to its strength and durability a PVB interlayer also absorbs 99.5% of UV light, assisting in reducing long term fading on internal fixtures and furniture.

A PVB or Ionoplast interlayer can be incorporated into the external glazing on projects where this type of UV fading is a concern. It is often used on projects where expensive artwork is on display or where the client has invested in real wooden flooring.

Interlayers for Acoustic Reduction

There are various ways to improve the acoustic performance of a glass unit. But the greatest level of noise insulation through glass can be achieved by including a laminate within the glass makeup.

The interlayers in acoustic glass act as a noise dampener, changing the ‘critical frequency’ (the point at which noise travels easily through the glass) closer to 100 Hz. Laminated glass dampens the decibel levels and filters high pitched noises (such as dog barking or car horns) that can be disruptive.

Improving the overall acoustic performance of a building cannot rely solely on the glass makeup itself however, it is a good place to start when working towards a healthy living environment.

For more information read our article: Sound Insulation in Glazing

Ionoplast Interlayers for Balustrading

One application where an Ionoplast strengthening interlayer is used most effectively is in frameless glass balustrades.

If you want to create a frameless glass design (with no continuous handrail) you have to use a glass makeup that will stay ‘in situ’ (ie remain in the upright position) even if the glass panels break. This is only possible to do with an SGP interlayer.

In addition, a High-Performance Interlayer has higher weather and edge stability than standard PVB interlayers making it a perfect application in frameless glass balustrades where the laminate will be exposed to the elements such as rain and snow.

In enhanced life longevity tests a glass balustrade laminated with an IQ High-performance interlayer was exposed to accelerated life simulations under a tropical environment and showed none of the edge defects that can develop on traditional PVB laminates as well as no change in colour, clarity or haze.

For more information read Regulations and Building Practice for Glass Balustrades