Ford PU foam containing graphene reduces noise and weight of cars
DENVER (ICIS) – Ford Motor has successfully incorporated graphene into polyols, producing polyurethane (PU) foam that reduces noise in automobiles while reducing weight.
The material is a finalist for the Polyurethane Innovation Award, awarded by the Center for the Polyurethanes Industry (CPI) at the Polyurethanes Technical Conference.
Graphene is a form of carbon that is one atom thick. It is almost transparent and yet so dense that helium cannot pass through it.
It rose to prominence in 2004 when two scientists from the University of Manchester described how they isolated the material using common duct tape. Their work won them the Nobel Prize in Physics in 2010.
Less than a decade after scientists won the award, Ford was able to incorporate graphene into polyols.
Now the foam is used in all North American Ford vehicles.
INCORPORATE GRAPHENE INTO THE FOAM
One of the biggest challenges in foam development was to disperse a nanomaterial like graphene in a viscous polymer and prevent it from collapsing during mixing, said Alper Kiziltas, technical expert, durability and emerging materials at Ford.
XG Sciences has supplied graphene chemically compatible with PU in sufficient quantities and at a reasonable cost, Kiziltas said. Eagle Industries, a Tier 1 PU moulder, participated in the processing of the foam.
Polyols with graphene couldn’t be processed like a typical additive, he said. To maintain the properties of graphene, the material had to be treated differently.
“Coupled with the needs of the Eagle manufacturing process, a unique method of combining and dispersing graphene with the polyol side of the foam was developed,” Kiziltas said.
Ford’s other challenge in developing the PU was conceptual. For new materials, it is commonly believed that an application will obtain better properties if it consumes more material.
Counterintuitively, Ford began to reduce the concentration of graphene in the polyol, Kiziltas said. As the concentration decreased, the performance of the resulting foam improved.
Graphene now makes up less than 0.3% of the foam, he said. “We have obtained very good mechanical, thermal and physical properties.”
Formulating PU with graphene was remarkably straightforward, Kiziltas said. It required almost no change other than adding graphene.
Other challenges were typical of those companies face when introducing new materials.
One was cost, because customers are price sensitive. Ford needed to make sure the new foam was at least cost neutral, Kiziltas said.
Also, since foam is a new material, Ford needed to make sure it would meet or exceed the part’s requirements, Kiziltas said.
The strength and compressive modulus have increased by about 20% compared to foam made without graphene, he said. Thermal deviation improved by 30%. The sound absorption coefficient has increased by 25%.
Components made from the foam were over 10% lighter, he said.
Automakers are keen to reduce the weight of their vehicles because they can travel farther with a tank of fuel, which allows them to emit less emissions.
Ford introduced foam in 2018, and it is used in components such as engine covers, oil pump covers, and fuel rail covers.
These covers are limited to internal combustion engines. However, Ford sees potential uses for the foam in electric vehicles (EVs).
It turns out that the white noise of the engines hides the rumble and squeaks that come with everyday driving. These annoying noises are much more pronounced in electric vehicles because they lack internal combustion engines.
Ford’s foam could be used in headlining, door panels and under the carpet to reduce noise from electric vehicles, Kiziltas said.
Companies outside the auto industry are also learning about foam, he said.
The polyurethanes technical conference runs until Thursday.
Interview article by Al Greenwood