Since the late 1970s, the standard glazing constructions for vehicles have been laminated glass for windscreen and toughened glass for the side and rear windows.  Over the next ten years, however, more and more vehicles will feature laminated side glass.  Matthew Beecham reports.

Laminated glass basically consists of two layers of shaped annealed glass bonded together by a tough, pliable and invisible layer of polyvinyl butyral (PVB). This glazed sandwich offers three main benefits: increased comfort, security and safety.  "Using laminated glass for side windows offers reinforced protection against attempted entry and good solar protection, filtering out virtually all UV rays," said Guy Faillat, director, body engineering, PSA Peugeot Citroën.  "It also has the benefit of soundproofing. There is also a return in the mass of a car for the same performance - laminated glass weighs less than thicker tempered glass. The use of polycarbonate in quarter windows is not to our way of thinking in view of the on-cost per kilogram saved."

Besides the intrinsic benefits of laminated side glazings, laminated glazing also offers an opportunity to create advanced glazings with additional features, such as coatings or wire heating for de-misting, or modified interlayers.

For some time, the European carmakers have led the way in terms of fitting laminated side glass, starting in the premium car segment.  A number of carmakers have already taken the decision to use 100% laminated side glass, such as Citroën (on the C6), Peugeot (407 and 607), Jaguar (XJ) and Mercedes-Benz (S-class). "The main difference, however, between the US and Europe is that the European carmakers tend to offer laminated side glazing as optional equipment, not as standard," said Michel van Russelt, market development director, Solutia Inc

Audi was the first to offer laminated glass all round on its A8 model in 1994. Since then, other luxury carmakers have offered it. For example, Lexus has been supplying laminated side glass as standard fitment on the LS 430 since November 2000. The luxury carmaker promotes the security enhancement features of the glazing to consumers in the showroom as well as the in-car refinement and lower NVH levels. Lexus points out that the LS 430 was winner of the What Car? security test for the last three years. The carmaker plans to fit laminated side glass as standard in the UK on the new LS 460 from November 2006.  A spokesman for the company told us there are no plans for it to permeate across the Lexus and Toyota range. 

Volkswagen in the UK also offers laminated side glazing as standard on certain models, namely the Touareg and Phaeton. In terms of rolling out this glazing across its model range, a spokesman for the carmaker said: "While we will not rule it out, there are currently no plans to roll-out laminated glass across the Volkswagen range." VW says laminated glass has a number of benefits for luxury and high-end products including security, safety and noise reduction. The carmaker says that although there are many advantages and disadvantages to laminated side glass, these should be evaluated on a model-by-model basis. "There is rarely a 'one size fits all' solution in an industry with so many niche products," added the spokesman.

"Growth for laminated side and roof glazing is very strong both in Europe and in North America, with total figures approaching 5m pieces produced every year at the global level," said Pete Dishart, global product marketing manager, PPG Industries.  "This option is also becoming appreciated in Asia where we see an important potential of growth in the coming years." 

Jay Pyper, North American automotive market development director for Solutia Automotive, told us:  "In North America, roughly 5-8% of all vehicles sold in the North American market have laminated front side glass. When you look at SUVs, I believe the total is in the 8-9% range which comes with laminated side glass - it is not an option but vehicles are sold with it as standard fitment. Now that the Dodge Ram pick-up truck features [laminated side glass as standard], that by itself means some 15% of the pick-up trucks sold in North America have laminated front side glass."

Americans are being offered laminated side glass mainly for its acoustical benefits although there are a lot of other reasons why they should be taking advantage of it such as the security and solar aspects.  Dishart added:  "Our Safe and Sound product continues to grow.  So we are really seeing a lot of demand for laminated glass here.  In Europe, however, laminated glass is perceived differently.  For example, we are selling laminated glass to Mercedes-Benz and the primary purpose seems to be for the inclusion of infra-red reflective coatings."

Although the trend to fit laminated sidelights started in Europe, there is increasing interest from North American carmakers. For example, at the 2006 North American International Auto Show, more than 40 production and concept vehicles featured laminated glass in side and rear windows, as well as roof applications.  Among those, Volvo currently offers laminated side glass as optional fitment to the S60, V70, XC70, and XC90. It is sold as a "convenience package" in the showroom.

In terms of selling the benefits of laminated side glass to consumers, Volvo aims to promote the fact that the glazing offers a quieter cabin and enhances personal security, in that it helps against smash-and-grab attacks. A spokesman for Volvo North America told us: "We like to give our customers the option and freedom of choice. For some they don't need it, others really like it." Volvo says the take-rate on each model in the US is still very low, less than 5%. "Folks want to spend money on audio instead," the spokesman said. Volvo says it has no plans to roll out this side glazing across the rest of its model range.

The use of laminated glass in side and rear windows is rapidly increasing in new North American vehicles, due to the various benefits that the product provides including security, occupant safety, acoustics, UV and thermal comfort. Rob Vandal, director of advanced product development, Guardian Automotive Products, believes the laminated side glass market in North America has grown very quickly over the past 2 - 3 years.  

He told us: "As vehicles become more luxurious then the primary path for entry in a luxury vehicle to deaden sound is now the glazing, especially the side glazing."  Although typically found on luxury cars, laminated side glazing is permeating down the segments.  Vandal added: "We see laminated glazing being increasingly offered as optional on middle segment cars while becoming standard on high segment cars."

Vandal is also secretary to the Enhanced Protective Automotive Association (EPGAA).  Established in 1999, its members include DuPont Automotive, Guardian Industries, PPG Industries, Saint-Gobain Sekurit, Sekisui America, Solutia Automotive. The EPGAA estimates that laminated glass has become a mainstream technology in the automotive industry, with about 1.3m vehicles produced annually with laminated glass.

"Laminated side and rear glazing has gained popularity over the last several years," said John Baxter, senior vice president, sales and marketing, Glasstech Inc.  "Many higher-end vehicles in Europe, Japan and North America are being fitted with laminated side and back windows. The percentage of vehicles equipped with laminated side and rear glazing will steadily increase. There are, however, economic considerations such as the added expense of laminated glass which will limit this rate of growth, particularly to lower-end vehicles."

Hayati Yarkadas, global marketing manager, DuPont Glass Laminating Solutions also sees an increasing number of OEMs offering laminated side glazing as an option.  He said: "Five years ago there were just a handful of OEM models offering laminated side glass. Today, there are some 50-60 models worldwide offering it as optional equipment, of which some luxury models offer it as standard.  While that is a very positive trend, the actual take-rates are still low.

Although people want their cars to be safe, they expect safety to come with the car as standard. So, if you are selling laminated safety glass as an option then it is not making the top of consumers' wish lists. Some OEMs are trying to sell laminated lights as part of the acoustic package - it is quieter - or some OEMs are selling it as part of a Solar comfort package. In that situation we are seeing more success because comfort is associated with quality more than safety is associated with quality. However, we believe, due to the clear safety, security and comfort benefits if laminated glass, penetration rates will start climbing significantly over the next few years."

DuPont is currently offering its Spallshield, the company's first generation plastic composite product for use in car sunroofs.  DuPont claims it represents a totally new alternative to pure organic plastic glazing or other existing glass-glass type laminates.   "Spallshield is not a new product," added Yarkadas. 

"It has been around for the past 22 years. It has been used in hurricane windows, bullet resistant glazing and anti-intrusion glazing applications with great success and it is still one of the strongest solutions in those applications. Its widespread debut in sunroofs and other automotive glazing is new. Spallshield is viewed as one of the most innovative products today by our customers due its unique benefits it brings to glazing. We have had a lot of interest from almost all OEMs.  There are two basic reasons for that. 

"First, Spallshield allows for a 30 to 40% weight reduction compared to standard laminated glass. Second, Spallshield significantly increases impact resistance.  In terms of impact resistance, Spallshield performs 5 to 8 times better than standard laminated glass for the same thickness. There is a cost benefit too.  Spallshield laminates cost the same or less than standard laminated glass in Sunroof applications.  We are working closely with the laminators and roof manufactures to reduce costs even further. We have made some significant headway there. 

"Over the next one or two years, we will see at least 14 vehicle models with Spallshield fitted on the roof.  We are working on projects with a number of OEMs which are in the process of converting their roof glazing from laminated or tempered glass into thin tempered glass with Spallshield.  There are also projects being worked on today to incorporate Spallshield in other Automotive glazing parts such as side lights, rear lights and windshields.  Widespread adoption of Spallshield has led us further upgrade our manufacturing facilities and increase our throughput."