A tiny innovation from 3M thatís having a big impact on materials technology. Minute hollow glass spheres, manufactured using a secret process, can be incorporated into a wide range of materials at the manufacturing stage to reduce the density and weight without compromising other core properties. At about 17 microns in diameter (a quarter the width of a human hair), the spheres are microscopic but make up in strength what they lack in size.
Mixing the glass spheres into a material such as plastic effectively reduces weight and density similar to the process in which foams are produced but, unlike air bubbles in low-tech materials, the soda-lime-borosilicate bubbles are not compressible, so are strong in both compression and tension. That allows some of the plastic in a component to be substituted with Microsphere filler without changing the endproductís durability and strength. In many cases, the more advanced blend is not only lighter than conventional plastic, but also stronger.
The glass additive wonít be replacing glass and carbon fibres in advanced composites, which are far stronger, but Microspheres are being used in combination with fibre reinforcement. Less bonding resin is required when mixed with the glass bubbles, resulting in a lighter finished product.
Weight reduction is a major area of research in vehicle design and development. Fuel consumption, handling, acceleration and braking performance all improve as vehicle mass is minimised, and virtually any plastic component can be made lighter when using a Microsphere composite.
As a bonus, the smooth surface and shape of the spheres allow them to easily flow through moulds and dies during the manufacturing stage, before the plastic component sets. Thatís allowed manufacturers to produce more complex and consistent components. As manufacturers increasingly turn to advanced plastics to save weight, the technology has never been more relevant.