In-car display cover demo solves polycarbonate production challenges

In-car touchscreens are becoming more than a mere display

Auto makers are upsizing their in-car displays to meet the growing demand for digital content. And as the driverless vehicle pulls into sight, the display will take on even greater importance as the key interface between a vehicle and its occupants. 

Ever-larger touchscreens will merge with the driver dashboard, the center console and passenger side panel. These new sculpted and complex 3D shapes will look beautifully simple, but will also be complex to design, engineer and manufacture.

Production solutions for a complex in-car display cover

Polycarbonate (PC) materials provide an additional solution to glass as the go-to solution for the in-car displays of the future. But in order to displace other solutions, PC production needs to become even more efficient. Birefringence, surface properties, bonding quality and production yield rate are the key issues to address. 

Working with partners in our value chain, we developed and built a fully functioning demo version of an in-car display panel of the future, using PC materials and advanced manufacturing processes designed to overcome production issues with large, complex 3D forms.

Materials that marry design freedom with production quality

The display cover materials solution centers on our Makrolon® Ai (automotive interior) product family. This range offers a high degree of design freedom, including the ability to customize color and transparency, along with the design freedom to integrate many functions and components. At the same time the materials deliver high impact resistance coupled with optical purity. During production, we achieved high lot-to-lot consistency and low variation in viscosity as well as a high yield rate.

Multiple molding process technologies to tackle material challenges

The technology solution combines multiple molding process technologies that each address particular material challenges. Injection compression molding (ICM) enabled the shaping of a very large yet thin display with low birefringence. Film insert molding (FIM) provided an anti-scratch and anti-abrasion surface, while a new 2-shot mold (2K) allowed rigidity and the integration of assembly features. Together, the three processes successfully reduced production defects, lowered internal stress and improved the production yield.

Optical adhesive solutions for durable, high bonding quality between display cover and touch sensors or screens

In close collaboration with partners we examined a range of optical adhesives and worked to find the right grades and adhesive processing conditions in order to minimize moisture and eliminate bubbles. 

Our 3D formable Makrofol® specialty film lends the display cover a high optical quality, as well as high resistance to scratches, abrasions and weathering. We are also working with our film group experts to develop film products with anti-glare, low reflection and easy to clean functions.

Application expertise from prototype to production

“The most impressive thing about this futuristic display cover is that it actually works – and the fact that it was built using real-life manufacturing processes,” said Zheng Xin Ping, President, Nantong Guandong Mould&Plastic Co., Ltd, “That’s why Covestro is our partner for polycarbonates, from prototyping through to full production.”