GLOBAL technology group 3M has developed a type of composite material that could make the cars of tomorrow lighter, faster and more fuel efficient – and the secret to the breakthrough is almost invisible.
Dubbed glass microspheres, the additive looks like a coarse powder. But it is millions of tiny glass bubbles that can be blended with the plastics used for car panels to increase durability and strength, but also reduce weight.
The tiny hollow spheres are specially developed to bond with a liquid resin or thermoplastic, forming a far stronger product than conventional plastic and filler formulas.
The secret lies in the inherent strength of a sphere, which can withstand large loads under both compression and tension yet is light thanks to its hollow construction. The process is like making foam by injecting air bubbles into a material, but without any loss of strength or rigidity of the finished product.
Glass is water- and temperature-resistant, non-porous and the millions of tiny air bubbles also impart better insulation properties depending on the application, further extending its list of potential uses.
3M says glass microsphere-reinforced materials have applications in countless industries including automotive, where lighter materials that do not compromise on strength have obvious advantages.
Chevrolet is already one step ahead, using the tiny glass bubbles to replace regular calcium carbonate filler in some of the Corvette’s plastics, saving about 10kg from the model’s bodyweight. That might not sound like much, but as more materials can be developed to use the glass bubbles, a greater weight loss is possible, says the maker.
The tiny beads are not a substitute for the high-strength carbon and glass fibres used in some composite materials, but can be used in combination with fibre reinforcement. The main advantage of the microspheres is in replacing ingredients in composites that do not impart strength such as excessive amounts of bonding resin.
Composite material manufacturers are constantly researching ways to reduce resin ratios. Microspheres are one solution that could boost carbonfibre and fibreglass performance to a new level.
Microsphere-enhanced materials have almost limitless applications in car design with everything from body panels, through engine manifolds and covers to dashboards and fuel tanks having the potential to lose weight without sacrificing strength.