Taking center stage at the Mitsubishi Heavy Industries Plastic Technology (Nagoya, Japan) stand at the recent IPF show near Tokyo was a massive panoramic roof molded by Toyota Industries for a long wheelbase version of the hybrid Prius vehicle available in Japan. The roof measured between 1050 and 1190 mm in width, and 1460 mm in length. Molded on a 3000emR-47-/160 two-component electric press (technically a hybrid press as final clamping is hydraulic) from Mitsubishi, the transparent PC component was 5 mm thick, while the black PC alloy frame was 3 mm thick. Overall shot weight was 12 kg.
|3-mm-thick glazing in Prius panoramic roof boasts tolerance of 0.05 mm.|
Explaining the complexities in molding such a large part, Yasuo Honda, General Manager, Sales Department, at Mitsubishi, said: "Thickness control for this part is very difficult. We employ four position sensors in the mold and active platen control in order to realize a tolerance of 0.05 mm in terms of part thickness. Normally with such a large part you'd expect tapering but we avoid this with four-point clamping and feedback from the position sensors."