BMW has selected Hexcel's HexForce® NC2® carbon fibre reinforcements for the part.

Hexcel says its NC2 technology enables the production of multiaxial carbon fibre reinforcements that are flat, lightweight and provide more uniform coverage than conventional non-crimp fabrics (NCF). This is a major advantage when producing thin composite structures requiring a cosmetic appearance.

In addition to NC2, Hexcel has been supplying BMW for several years with HexForce® PrimeTex® 3K spread fabrics for the outer skin of the carbon fibre roof. HexForce PrimeTex fabrics have been processed to provide a very close weave and uniform cosmetic appearance.

Hexcel says supplying products tailored to the requirements for the M-series roof was challenging for three main reasons: very specific reinforcement widths are required, with tight thickness tolerances and large volume production.