Interiors specialist Johnson Controls used machinery and process innovations to apply a two-colour foil to a single-component substrate made of natural fibres to produce innovative interior door trims for the recently updated BMW 5-series.

"The new process ensures both cost-effective production and a high-quality finish," the supplier said.

Two-colour components of automotive interiors up until now have generally been produced as multiple parts before being applied to one another. As a result, seams and gaps remain visible with this method. It also makes it difficult in some cases to observe strict weight limitations.

"Working closely with BMW, we broke new ground with this technology - being the first company to retain a single-component substrate and successfully cover it with a two-colour, off-the-roll plastic foil" said Achim Hosenfeld, vice president and general manager of Johnson Controls.

Anyone who has ever tried to wrap an asymmetric object with striped gift wrap paper in such a way that the lines are absolutely parallel, even along the edges, can probably imagine the kind of challenges engineers faced.

To ensure a high-quality finish and harmonious overall effect, exacting tolerances must be observed where the two colours meet on the door panels.

The film is stretched when it is applied to the substrate. This distorts the colour demarcation line, which then has to be brought back into proper alignment.

In the fully automated production process, machinery and tool advances ensure the colour demarcation lines stay within the exacting tolerances at all times.

The 5 series made at the Chinese BMW plant in Shenyang is also being fitted with these innovative door panels.

The company also supplies the eight-inch display for the rear seat entertainment system for the long-wheelbase version produced specially for the Chinese market.

It also provides the integrated garage door opener, HomeLink, worldwide as optional equipment.