Innovation within the world of laminated glass can come in many forms. Sometimes, it is the interlayer itself that provides a new feature that excites architects, such as jumbo widths (up to 3.3 m), colors, enhanced mechanical properties, or better acoustical performance. In other cases, the laminate interlayer becomes an enabler of other performance attributes that expand function and create new opportunities.
Cover Image: TWA hotel, Courtesy of the TWA Hotel at JFK (TWA / David Mitchell)
Three new products that incorporate Kuraray’s SentryGlas® ionoplast interlayer are examples of the enabling power of interlayer. These are Glass BirdProtect™ with DotView™ One—Way Vision from McGrory Glass, the Flood Window System from Fenex, and Bendheim’s Ventilated (and Non-Ventilated) Glass Rain & Wind Screen Systems.
Bird-friendly glazing is relatively new to some designers, however, the subject of bird fatalities due to collisions with glass on buildings is certainly not new to organizations like the American Bird Conservancy (ABC). They have estimated that as many as a billion birds are killed every year after colliding with glass. Why? According to the ABC, “birds don’t understand the concept of glass as an invisible barrier that can also be a mirror. They take what they see literally: Glass appears to be habitat they can fly into, whether that habitat is reflected or visible through glass.”
The challenge for the glass industry has been to create a visual deterrence for birds, and still maintain transparency to the human eye. Several solutions have been identified and tested according to actual in-flight tunnel testing. The testing methodology is the subject of a new ASTM International Standard that is in development under the C14 Committee on Glass. Chaired by architect Stephen Knust, director of sustainability at Ennead Architects in New York and Christine Sheppard, PhD. of the American Bird Conservancy, this standard will result in a bird collision deterrence material threat factor for glazing.
Along with the development of an industry test standard, bird-friendly regulations have been adopted by a handful of cities and states in the U.S. and Canada. In 2019, the Bird-Safe Buildings Act was introduced into the U.S. House of Representatives. The bill is aimed at General Services Administration (GSA) government buildings and requires compliance to a modified glass standard under specific conditions. For instance, from ground level to forty feet, façades must include an element that deters bird collisions without completely obscuring vision, such as secondary facades, netting, screens, shutters or exterior shades. Other acceptable glazing solutions include ultraviolet (UV) patterned glass that contains UV-reflective or contrasting patterns that are visible to birds, patterns on glass designed to restrict horizontal spaces to less than 2 inches high and vertical spaces to less than 4 inches wide, and opaque, etched, stained, frosted, or translucent glass.
Designers with projects intended for LEED® compliance can take advantage of LEED Pilot Credit 55: Bird Collision Deterrence. A material threat factor of the façade component material is required to support the award of the credit.
Innovative Bird-friendly products
One innovative bird-friendly glass solution has been brought to market by McGrory Glass, a glass fabricator located in Paulsboro, New Jersey USA. Their product, Glass BirdProtect™ with DotView™ One-Way Vision, was recognized as the “best product” in the “Openings-Safety Category” by the Architects’ Newspaper’s Best Products Awards for 2020. This composite was laminated with Kuraray’s SentryGlas® interlayer.
BirdProtect™ Clear incorporates a UV solution that is visible only to birds. The only way a human eye can detect the bird deterrence pattern is by shining a UV light on the glass. BirdProtect™ Clear has a Threat Factor Rating of 19, which complies with the American Bird Conservancy’s Threat Factor rating score of 25 or lower. According to President Chris McGrory, “UV technology satisfied a desire on the part of architects for transparency, but also addresses the capability of the glass to deter bird strikes. There are decorative options that can enhance the appearance of the glass if that is the building owner’s desire.”
McGrory has added a new dimension to the clear product by adding their DotView™ one-way vision glass to the final glazing. This enables a customized, decorative view from the outside and a clear view from the inside to the outdoors. The images are created with a precision dot-on-dot printing process that renders images and colors crisply, without blurring. The façade of the S.I. Newhouse School of Public Communications III at Syracuse University, designed by Ennead Architects, illustrates this combination of bird-friendly and decorative technology.
Hurricane impact glazing has been used in windborne debris areas of the U.S. for years. Although the building code requirements allow for shutters and plywood coverings, laminated glass is the only option that enables continuous protection of a home or building from flying debris during a storm. Both Trosifol® PVB and SentryGlas® ionoplast interlayers are part of systems tested and certified for large and/or small missile compliance.
What’s new on the market today are flood windows that not only address debris impact but rising flood water that can occur during a storm. The Federal Emergency Management Agency (FEMA) states that “flooding is the most common natural hazard in the United States and results in more fatalities and higher losses on average than any other natural hazard. Since 2001, the average annual flood losses in the United States were more than $10.4 billion, and from 1978 to mid-2012, the National Flood Insurance Program (NFIP) paid more than $41.3 billion in flood insurance claims.”
Fenex, a U.S. company specializing in custom and oversized windows and skylights, is a leader in flood windows. These systems are passive dry flood barrier systems that have been tested to withstand more than ten feet of water as well as large missile impacts. They comply with several standards including Factory Mutual/ANSI Standard 2510 for flood and hydrostatic testing and FEMA Standard 936 for floodproofing Non-residential buildings. Stephane Theriault, President of Fenex LLC notes, “It was very important for us to meet the industry standards in order to gain market credibility. Our testing with Factory Mutual at our one-of-a-kind testing facility was challenging, but the positive outcome was the validation we needed for the marketplace.”
There are many benefits to flood windows. Besides keeping water out, these windows preserve the view to the outside while being customizable to fit and even enhance the project’s design. Like other hurricane impacts, the Fenex flood windows incorporate SentryGlas® laminates for safety and security. Vice President of Sales Brian Johnson adds, “SentryGlas® interlayer was a proven performer in our other impact systems that were tested for large missile and high velocity wind/hurricane zone performance. We were looking for the same level of performance in our dry flood barrier system.”
Flood Windows in Action
Located in a designated FEMA flood zone in Maryland USA, Whitehall Mill now features a new passive floodproof window system that will ensure the safety of this historic renovation of the 1865 Clipper Mill. FENEX manufactured 14 windows that were installed in ground floor openings and positioned under the design flood elevation. Each opening consisted of one solid 10 x 15 cm (4 x 6 ft) window where faux mullions were installed to create the architectural look to match the standard windows above. The goal was to provide flood protection while maintaining the historical aesthetics of the original building.
In addition to the window design in the Whitehall project, Fenex provided custom curved windows for Bottega Veneta, a high-end retailer in the Miami Design District. FENEX worked with the Arup/Valerio design team to create a unique window system that met the client’s impact and design objectives. The 2.4 x 5.6-meter (7.9 x 18.3 ft) windows incorporated S-shaped curved insulating/laminated glass.
New Glass Façade Systems
Façade innovation abounds at Bendheim with its Decorative Ventilated Glass Façade System and the Decorative Glass Rainscreen System, both utilizing laminated glass. According to Said Elieh, Vice President of Systems and Innovation at Bendheim, “Ventilated glass façade systems act as a screen from rain and wind, helping to protect the building from moisture damage. A variety of aesthetic options are available to create a decorative effect, as well as act as a bird-friendly solution.”
Johnson County Community College
Designed by BNIM Architects, the new Fine Arts + Design Studios at Johnson County Community College in Overland Park, KS, has a 51.8-meter (170 ft)-wide ventilated glass façade with a fine-dot frit on surface one of the glass that creates a brilliant white appearance. The fritted glass is laminated to etched glass on surface four to create a strong light-diffusing effect.Clear SentryGlas® ionoplast interlayer was used to bond the laminate together. Behind the translucent glass façade, second-story windows fill the art studios with soft, glare-free filtered daylight. The ventilated glass facade is also designed so that it can eventually double as a projection screen for student art.
Inova Schar Cancer Institute
The Inova Schar Cancer Institute in Fairfax, Virginia designed by Wilmot Sanz Architecture, features Bendheim’s rainscreen system. The rainscreen is comprised of laminated glass on the exterior. Behind it, there is a layer of rigid insulation, a thick concrete exterior wall, and highly specialized and sensitive testing facilities. This is the first project in the U.S. (3rd in the world) using this type of vertically-and-horizontally-overlapping (shingled) glass rainscreen system. The design features bird-friendly textured laminated glass with translucent white SentryGlas® interlayer. According to Elieh, “The luminous, light-diffusing glass is ideal for the back-lit application, and the structural ionoplast interlayer reinforces the relatively thin 10mm glass”.
Laminated Glass Interlayers
Innovation also applies to laminated glass interlayers. Today standard PVB interlayers have been augmented by interlayers of different types for a range of architectural applications. In the Trosifol® PVB interlayer portfolio there are now ultra-clear, acoustical, stiff interlayers, and colours. Trosifol® UltraClear offers a complement to laminates comprised of low iron glass and reduces the “yellowish” interlayer appearance that can occur with multi-ply security laminates made with standard clear PVB. Trosifol® acoustical interlayers help to raise the overall sound control properties of both monolithic laminates and insulating glass units. Trosifol® Extra Stiff increases the structural performance of laminated glass, especially in minimally supported interior applications where the temperature does not exceed 30 °C. (86 °F).
Interlayer colors have expanded from the standard clear PVB to a sweeping range of options, including opaque white and black. This not only effects transparency and translucency but gives designers the option of using opaque laminated glass for other applications, such as white boards and shelving.
Global marketing manager Christoph Troska, adds, “interlayers have been developed over time to expand the overall performance of laminated glass in the built environment. The architect now must follow a decision tree to arrive at the best interlayer choice. For instance, is this an exterior application with open-edged glass? Is this a fully supported glass system? With the variety of interlayers on the market, it is important to know the designer’s intended use and expectations.”
By now designers are familiar with SentryGlas® and its advantages. The interlayer has been on the market for close to 25 years, expanding systems options in the hurricane and structural glass markets, as well as in exterior edge-exposed applications. This interlayer has become synonymous with spectacular extraordinary projects like the Apple Cube on Fifth Avenue in New York, the Grand Canyon Walkway, and the glass slide at the U.S. Bank Building in Los Angeles. However, there are literally thousands of projects that have been made possible because of this unique ionoplast interlayer. Now it is bigger and better with the launch of SentryGlas® Xtra, a more fabricator friendly version of the original.
SentryGlas® interlayer with jumbo roll sizes up to 3.3 meters to meet the vision of designers for larger widths of glass panels
Glass continues to be a popular material across the globe for its accessibility, cost, and performance. It is often the material of choice for new construction, as well as upgrades to older buildings. Troska concludes, “The process of innovation keeps the R&D folks on their toes as they continue to identify the needs and opportunities of specifiers and building owners.”
There are many drivers, including sustainability, energy efficiency, resilience, comfort, security, and safety. The list is challenging, but whether it is bird deterrence or the threat of floods, the interlayer will continue to evolve with the new systems that are brought to market.
This article was originally published in IGS Magazines Spring 2021 Issue: Read the full Magazine here for more thought-leadership from those spearheading the industry
Author: Ron Hull, P.E. is the Kuraray Trosifol® PVB marketing manager for the Americas
He joined Kuraray in 2016 and has over 15 years of experience in the architectural construction market. Ron is an active member of the Florida American Institute of Architects (AIA), Construction Specifications Institute (CSI), Fenestration and Glazing Industry Alliance (FGIA) and serves on the Facade Tectonics Institute (FTI) Special Advisory Council and as the secretary and treasurer of the Glazing Industry Code Committee (GICC).