One of the key advantages of microspheres is their low density. It is therefore a natural connection to use them in industries where volume and strength is desired and weight is not.
One such market is the automobile industry, that has hit upon the potential that microspheres hold to be both bulky and yet lightweight. For car makers, having a large volume to mass ratio saves money. Which is why in July 2016, the new Chevrolet Corvette used a composite for making body panels that included glass microspheres.
As the industry journal, Plastic News, reported at the time, “Continental Structural Plastics Inc. has developed a sheet molding compound in which glass microspheres replace calcium carbonate filler and shave 20 pounds [9kg] off the sports car’s Stingray Coupe model weight.” Adding that, “the trick to the SMC formulation is getting the microspheres to stick better to the thermoset polyester matrix. CSP has developed a silane treatment for the beads so that one end of the silane molecule sticks to the glass microsphere and other to the resin.”
Probir Guha, Vice President of manufacturer Continental Structural Plastics Inc, explained how, “the typical SMC formula for this type of vehicle application comprises 20 percent by volume of glass fiber reinforcement, 35 percent resin and 45 percent filler, usually calcium carbonate.”
“This new SMC is cost competitive with aluminum,” noted Guha, adding that, “tooling costs are [also] low. For a production run of fewer than 150,000 vehicles, such composites can lower tooling costs by as much as 50 to 70 percent versus steel or aluminum.”
Given the rising cost of fuel, any weight saving that can be made in a vehicle not only saves money but also increases speed and is better for the environment. In an industry with a bad ‘green-image’ automobile manufacturers may well be looking to microspheres as a solution to vehicle efficiency more and more in the future.