At a recent conference, Ford Motor demonstrated its innovative graphene-enhanced polyurethane (PU) foam, which can reduce car noise while reducing car weight. The material was selected as a finalist for the Polyurethane Innovation Award, which was awarded by the Center for Polyurethane Industry (CPI) during the conference. The foam is said to be used in all Ford North American vehicles.
Alper Kiziltas, an expert on sustainable development and emerging materials technology at Ford, said that one of the biggest challenges in developing foam is to disperse nanomaterials such as graphene into viscous polymers and prevent them from collapsing during the mixing process.
Kiziltas said that XG Sciences provides graphene chemically compatible with PU in sufficient quantities and at a reasonable cost. Eagle Industries, a first-class PU molder, is involved in foam processing.
He said that polyols containing graphene cannot be processed like typical additives. In order to maintain the characteristics of graphene, the material must be treated differently. "Combined with the requirements of Eagle's manufacturing process, a unique method of combining and dispersing graphene with the foam polyol side was developed," Kiziltas said.
Another challenge for Ford in developing PU is conceptual. For new materials, it is generally believed that if the application consumes more materials, better performance will be obtained. Kiziltas said that contrary to intuition, Ford began to reduce the concentration of graphene in polyols. As the concentration decreases, the performance of the resulting foam improves.
He said that graphene now accounts for less than 0.3% of the bubble. "We have obtained very good mechanical, thermal and physical properties."
Kiziltas said that formulating PU with graphene is very simple. Apart from adding graphene, it hardly needs any changes.
Other challenges are typical challenges that companies face when introducing new materials.
One is cost, because customers are very price sensitive. Kiziltas said Ford must ensure that the new bubble is at least cost-neutral.
In addition, because foam is a new material, Ford must ensure that it meets or exceeds the requirements for parts, Kiziltas said.
He said that compared with the graphene-free foam, the compressive strength and modulus have increased by about 20%. The heat distortion is increased by 30%. The sound absorption coefficient has been increased by 25%.
He said that the weight of parts made of foam has been reduced by more than 10%.
Automakers are eager to reduce the weight of their vehicles because they can travel longer distances with a tank of fuel, thereby reducing emissions.
Ford introduced this foam in 2018 and it is used in components such as engine hoods, fuel pump covers, and fuel rail covers.
These covers are limited to internal combustion engines. However, Ford sees the potential use of foam in electric vehicles (EVs).
It turns out that the white noise from the engine masks the rumble and squeaks in daily driving. These annoying sounds are more pronounced in electric vehicles because they do not have internal combustion engines.
Kiziltas said that Ford’s foam can be used under roof linings, door panels and under carpets to reduce noise from electric vehicles.
According to Kiziltas, companies outside the automotive industry are also asking about this bubble.