TOYOTA Adopts Resonac’s Foamed Moldings for Use as Exterior Parts of “LEXUS RZ”

— Resonac’s original technology reduces weight of parts by more than 30% —

April 26, 2023
Resonac Holdings Corporation

Foamed Moldings for exterior parts manufactured with original technology developed by Resonac Corporation*1 (President: Hidehito Takahashi) have been adopted by TOYOTA MOTOR CORPORATION for use as exterior parts of “LEXUS RZ,” which is the first battery electric vehicle (BEV) of TOYOTA’s luxurious car brand, “LEXUS.”  Resonac’s Foamed Moldings have been adopted by TOYOTA for use as LEXUX RZ’s back-door garnish, a resin part to be attached to the back-door, and other parts (see Picture 1).  Resin parts manufactured with Resonac’s original foamed molding technology for exterior parts save weight by more than 30% compared with conventional resin parts.

Resin products manufactured with conventional foamed molding technologies for exterior parts had difficulty in realizing properties required for automotive parts, including external appearance and durability.  However, in 2016, Resonac successfully developed original foamed molding technology for exterior parts through optimization of material, molding, and dies, and applied this original foamed molding technology to the process to mass-produce automotive exterior parts for the first time in the world*2.  At the beginning, this technology was applicable only to PP (polypropylene).  Later, however, Resonac succeeded in applying this technology to ABS (acrylonitrile-butadiene-styrene).  Now, this technology enables us to reduce weight of many kinds of automotive parts.

Picture 1: LEXUS RZ
Picture 1: LEXUS RZ


Picture 2   A section of Foamed Molding for exterior parts
Picture 2   A section of Foamed Molding for exterior parts


In recent years, the automotive industry has been making effort to promote weight reduction of cars as a measure to reduce CO2 emission through improvement in fuel efficiency, aiming to contribute to environmental protection including the movement for carbon neutrality.  Especially, BEV strongly requires weight reduction of parts because BEV is heavier than conventional gasoline-fueled car due to loading of large batteries. 
Many automotive exterior parts are made of resins, and resin parts are also required to realize further weight reduction.  However, further thinning of resin parts is very difficult because it causes rigidity problems.  foamed molding technology for exterior parts is now attracting car manufacturers’ attention because this technology enables resin parts to realize weight reduction while maintaining rigidity.  In addition, this technology reduces life cycle CO2 emission of resin parts through reduction in the amount of materials used.

As a “Co-creative chemical company,” the Resonac Group aims to contribute to sustainable development of global society.  Regarding the automobile industry, the Resonac Group will aim to apply this foamed molding technology for exterior parts to more kinds of automotive parts for larger variety of car models, thereby contributing to improvement in fuel-economy and electricity-economy of cars, and reduction of their CO2 emissions.


*1: This is Resonac’s original technology to realize rigidity and weight reduction of resin parts simultaneously by partially foaming resins injected into dies for molding.  Injected resin is foamed only in the central part of the space in the die, and surfaces of the part maintain smoothness.  Therefore, this technology is adopted by many car manufacturers for use in production of automotive exterior parts which require good external appearance.

*2: Based on Resonac’s research. (As of March 2023.  We researched into cases of patents and their adoptions by car/automotive-part manufacturers concerning technologies similar to Resonac’s foamed molding technology for exterior parts applied to mass-production of automotive exterior parts.)

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