Liftgate design puts modified filament winding to the test

Automotive liftgates, or rear-hatch doors, have slowly been transitioning from metals to composites for decades. While it wasn’t until 2013 that the first all-plastic/composite liftgate, minus metal support structure, was commercialized, most liftgates today still feature this support component on which outer skins and inner panels are attached, particularly on larger, heavier sport-utility vehicles (SUVs) and crossover-utility vehicles (CUVs) with bigger rear doors.

However, what may well be the next evolution in composite liftgates debuted in 2019 on the Toyota Supra sports car from Toyota Motor Corp. (Toyota City, Japan). A filament wound composite frame replaced a metallic frame and is said to offer higher stiffness and strength at lower weight than traditional metal structures, with greater design flexibility, especially in tight packaging space. Reportedly, the filament winding process has been modified to such an extent that, as interest grows and applications proliferate, it can meet the speed and cost targets of higher-volume vehicle production. This is how the design and technology came to be.

Trilateral manufacturing
Magna International Inc. (Aurora, Ontario, Canada) is a Tier 1 integrator in North America, but in Europe, its Magna Steyr AG & Co. KG (Graz, Austria) subsidiary also designs and assembles complete cars for OEMs that need extra manufacturing capacity.

Recently, Magna participated in an interesting program involving automakers Toyota and BMW AG (Munich, Germany), which have worked cooperatively on design and manufacturing projects since 2013. For its latest effort, Toyota was looking to revive its Supra nameplate and had partnered with BMW to provide design and tuning for the vehicle and a sister car, BMW’s 2-seater Z4. The two vehicles share engine, suspension and steering systems. Magna Steyr would assemble both cars in Graz, as well as supply the Supra with seats, body panels, door latches and liftgates. While there’s plenty of innovation on both cars, the liftgate incorporated in the Supra is where composites design innovation is most apparent.

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