A grade of Piocelan polyethylene/polypropylene (PE/PP) hybrid foam developed by Sekisui Plastics Co., Ltd. (Osaka Japan) has been adopted in the seat base of Toyota Motor’s latest C-HR model that debuted in Japan last September. Sekisui Plastics is also responsible for molding of the component, which is processed using a wire insert-molding process. The wire frame extends greater mechanical strength to the component and was previously added to the seat assembly in a separate step.
|Hybrid PE/PP foam seat base is insert foam-molded with a wire frame.|
Japanese automakers have for some time employed hybrid foam in seat structures as a means of reducing the quantity of polyurethane (PU) foam and wire frames employed, thereby leading to lightweighting. However, this is the first instance whereby a wire frame has been inserted into a tool in a foam molding process. Sekisui Plastics was exhibiting the technology at the Automotive World show incorporating the 7th Automotive Lightweight Technology Expo held January 18–20 in Tokyo.
The key to successful deployment of the insert molding technology, according to Sekisui Plastics, is the dimensional stability of the foam molding. The foam part reportedly exhibits dimensional precision of +1 mm. Further, Sekisui Plastics notes that use of the PE/PP hybrid foam can allow automakers to reduce their usage of PU foam by up to 30%.
Furthermore, Piocelan’s shock absorption performance helps prevent passengers from sinking into their seats while it absorbs impact in the event of accidents.