With the trend for central console designs to be larger, more curved and more freeform, OEMs have begun to pay more attention to Tier 2 providers and their abilities to mold new, sleek surfaces to match car makers’ imaginations. Ultimately, these consoles are positioned in the face of the final customer, and as a result, the materials needed to make these designs are revealing themselves to be increasingly crucial.
Dr Matthias Schiller, chief technology officer and director for product and process development at glass specialist FLABEG Group, says, “With the availability of touchscreens, design trends have moved toward uniform surfaces without visible control elements. The main advantage of this trend is intuitive operations such as tapping, dragging and dropping or swiping with one finger, turning, pinching to shrink or spreading to enlarge objects with two fingers.”
Lars Frick, global sales director in FLABEG’s automotive glass division, adds, “I think that the design is moving this way because, in the end, it gives an extraordinary and futuristic appearance, that is what consumers are looking for. Glass is an ideal material for future projects because large and smooth cover designs made from glass have a lot of advantages instead of using plastic. Furthermore, glass is also nice to touch and feel and resistant to scratches and fluids such as alcohol used to clean the surface. Something very interesting to consider as well is that big plastic display covers have a higher weight compared to glass. Glass can be very thin, light and robust at same time.”
However, one key pain point of a large, flat dashboard is its usability. Frick explains, “These console designs are like having iPads in your car. However, in my living room I don’t need help finding the buttons on my iPad because I can stare at them. In a car, I’d rather not. We can ensure OEMs can deliver these sleek, modern designs, without sacrificing safety.” With its automotive interior facilities in Furth im Wald, Germany, FLABEG can mold individual peaks and troughs into one piece of glass. Schiller says, “Surfaces with integrally formed objects – like guides for the fingers, raised or grooved buttons, sliders or jog dials – can assist the operator when interacting with the touch display, without visual cues.” In other words, giving end users a fixed point to find with their fingers is expected to help drivers navigate their consoles without taking their eyes off the road.
Raise a glass
So how are these large, monolithic pieces of glass being bent to OEMs’ wills? The standard thickness for automotive glass design is between 1.1mm and 2mm. To include specific designs in this delicate surface and reduce the risk of breakage, FLABEG chemically strengthens its glass. Chemical strengthening hardens the glass by bathing it in potassium salt at more than 400°C, which causes the glass to swap its small sodium ions for the water’s larger potassium ions. This process makes it more flexible and resistant.
With advances like this, glass can be bent between approximately 0.7mm and 10mm thickness. According to FLABEG, there are traditionally two different ways of bending glass for automotive designs: press bending or sag bending. Both methods begin by warming the glass above its softening temperature until it can gently bend. From there, the press bending technique pushes a tool into the glass to form the desired shape, cools it down and finally anneals it to release the pressure it has built up inside. In contrast, sag bending warps the heated glass by enabling it to slump down into a premade mold. For special parts – like the 3D free-form designs for automotive consoles – the sag bending process can also be supported by a vacuum, where professionals will use a mound and suction to form the glass into specific and difficult shapes.
Of course, forming physical characteristics into the console does mean limiting designers’ flexibility more than a purely software-based user interface would. However, that’s not to say it sets the software functionality in stone. “You can change the functionality of the buttons and what they signify for the software behind the glass,” Schiller says. “There doesn’t have to be only one button for the temperature and one for the radio. One button could scroll through menus so you can adjust the volume or the temperature with a fixed slider. This also means you can have buttons without cluttering the entire dashboard with them.”
When drivers do need to glance at their dashboards, however, it is important to ensure the functionalities are easily seen and understood. This means minimizing the amount of light that is reflected by the glass. Traditionally, glass specialists would rely on an anti-reflection (AR) coating, as this can minimize reflections to below 1% on flat glass. However, this solution makes no sense on curved glass. This is because AR coating always has a tint of another color when looked at from an angle, so the range of angles on show with a protruding button would alter (necessitate a change to) the console design. Instead, for automotive applications the industry relies on glass with etched surfaces. Etched surfaces are created with hydrofluoric acid, which makes mini structures in the glass that ensure it is imperceptibly uneven. These mini structures reflect light at a variety of angles and therefore reduce the amount of light reflected into the driver’s eyes.
All these solutions occur in FLABEG’s clean rooms and automated production lines. Frick comments, “We automated the pick and place system so nobody needs to be in the clean rooms or touch the glass. Instead, the glass is driven around by our small, autonomous-driving robots, which I like to call our R2D2s.” To ensure the screen-printing quality, there’s also housing around each piece of machinery and overpressure inside. This minimizes the disturbance caused by dirt. After the robot delivers the finished product from the cleaning room, that glass must then undergo the company’s automated, 100% camera inspection process. This process uses four cameras to analyze 16 channels of light from different angles. If the cameras pick up an unexpectedly dark or light spot, this could mean an accidental hole or piece of dirt has gotten into the glass. If they pick up a line of spots, this could indicate a scratch. After it has been checked for design deviations, the glass is tested in a variety of temperatures, humidities and pressures. Schiller says, “Alongside dimension, movement and cutting alignment checks, we also do regular lab tests, like climate chamber tests, anti-fingerprint tests, color measurement tests or the adhesion of the paint tests (the latter is tested every day).”
These tests are particularly crucial when it comes to installation. As glass expands less than plastic when heated, fitting these large consoles into plastic dashboards poses a challenge. Schiller explains, “You have to be wary of how the surrounding design will react between -40°F [-40°C] and 140°F [60°C]. You must leave enough gaps for the plastic not to expand too wide and then break the glass from the console. That’s another reason why we want the console to be one piece of glass – so we only have to worry about the frame positioned around the glass.” Moreover, the glass must be seamed with an angle on a 90° laser-cut edge to ensure it is rounded off enough to avoid scratching the surrounding system when installed.
With safety firmly at the heart of the company’s integrated physical button shapes, it’s hard to ignore Covid-19 and potential further pandemics. Looking to the future, antibacterial coatings seem poised to become the next phenomenon and FLABEG plans to begin investigating this, both OEM interest as well as potential pandemic selling points. In particular, silver’s antibacterial properties are expected to come into play soon as the development cycle keeps turning.
Overall, the specialists highlight the inherently hygienic nature of a large glass installation. As Frick says, “A monolithic piece of glass is not only easier to clean than classical buttons, it’s also cleaner by design. Elsewhere in your car, you have gaps – meaning dirt gets stuck and the car is unhygienic. However, if you have one piece of glass, you have no problem with that. It really is the material of the future.”