By Cameron Chai
Researchers from the Texas A&M University and the National Institute of Standards Technology (NIST) discovered unique carbon nanofiber-filled coatings that can replace the traditional fire-retardants employed in the polyurethane foam (PUF) utilized in upholstered mattresses and furniture. This coating beats the performance of other coatings by at least 160%.
The test results reveal that by coating polyurethane foam (PUF) with an arrangement that combines thin layers of polymers and carbon nanofibers, considerable safety against fire can be ensured. Rick Davis, a researcher, stated that the experimental coating was found to create a fire-resistant armor inside the porous-filled foam. The experimental technology utilizes fire-retardant coating comprising carbon nanofiber to cover all the cracks and nooks on the spongy surface of PUF. The surface treatment rendered by this new approach has the ability to allow a least flame-generating PUF without causing a major change in the production process and thereby saving cost and time, explained Davis.
The commercially available square samples of PUF were coated with four bilayers, each bilayer comprising a combination of carbon nanofiber and polymer. On an average, the thickness of this fire-retardant coating was 360 nm, which increases the foam mass by just 3%. In that, the carbon nanofibers contribute 1.6 % mass of the foam. These nanofibers got clumped within the top surface at about 360 nm similar to matted whiskers.
A standard fire testing was done by the team to evaluate the fire intensity in both the uncoated and coated PUF by measuring the highest heat-generation rate from a burning sample. It was found that the carbon nanofiber coatings reduced 40 % of PUF flammability. The obtained result was over 3 times better when compared to the same carbon nanofibers placed inside the foam.