Continuing just-auto’s series of interviews with leading glass manufacturers, Matthew Beecham talked with Dr. Volkmar Offermann, marketing director of Saint-Gobain Sekurit International about trends in automotive glazing.

The Citroen C3 is currently offering the largest windshield and the smallest roof on a hatchback. Do you think that large windshield/small roof is the way forward?

The C3 Citroen has set a completely new benchmark.  I am sure that we will have more cars of this sort in the future. So we see a growing market for, what we call ‘2 in 1 windshields’ where the traditional windshield meets the glazed roof part.  Cars with this type of glazing are more exciting to drive.

Are there issues still with shading of these large windshields and roofs?

In order to have good thermal management inside the vehicle, we believe that two things are needed: the first is, let me call it the roof part of the 2 in 1 windshield should be darker than the windshield part.  So in terms of sunlight and energy it lets inside the vehicle, it should be closer to a traditional roof glass inside a vehicle. Secondly, there needs to be a a kind of roller blind or other sunshade to block the extreme sunlight. 

The boundary between the windshield and the glass roof on some vehicles is decreasing all the time. I guess this is the way the market is heading – toward an almost seamless canopy of glass from windshield to roof line?

Generally speaking, these gaps are becoming smaller and smaller.  Car manufacturers are building the vehicle body with higher and higher precision.  In turn, this gives them some new design opportunities and, of course has the consequence that the quality requirements for all the parts are increasing constantly. Aesthetically speaking, the gap results in the flush design which is appealing as well as being good for things like wind noise and other topics which are relevant today.

Could we expect to see more solar panels on cars in the future? It’s only really niche examples, isn’t it, the Toyota Prius but do you think it will stay a niche, these solar panels on roofs?

Good question and I believe today nobody has the answer. When you look at solar cells, there are two possible applications: the first one is to simply charge the battery of an electric vehicle.  Here, we are quite sceptical whether this is a good application.  The other is to use photovoltaic cells to run, for instance, a ventilation system which takes some of the heat out of a car when parked-up.  While this latter approach means that the air conditioning does not have to operate for quite so long, thereby having a positive impact on the driving range, the question is whether it has a good relation between value and cost. More investigations are needed in order to see whether this is the case.

Where do you see the opportunities for polycarbonate glazing in the automotive industry? 

The remainder of this interview is available on just-auto's QUBE