3M brings glass microspheres into injection moulding

22 March 2007 – 3M has developed its glass filler materials to a stage where they can withstand injection moulding and extrusion pressures of 30,000 psi, making high-volume production of lighter and cheaper interior components possible, the US company claims.

The iM30K glass microsphere additives are 40% stronger than 3M’s previous high strength glass microspheres and, at 18 microns, are approximately half their size.

The company says this means the filler material can be used as an alternative to glass fibre, calcium carbonate and talc in the moulding and forming processes that are common in the automotive industry.

A 19-month long series of tests carried out by South Korea’s Hyundai Mobis IP Core Part Development Project compared PC/ABS with a new polypropylene material filled with iM30K additives for use in moulding automotive instrument panel core parts.

Results from this showed a 16.8% weight reduction and the finished part cost was 50% lower than PC/ABS versions. “In addition, we experienced improved material flowability than PC/ABS and better dimensional stability compared to current talc filled polypropylene,” said S. Ka, research engineer for the cockpit module design project.

The new generation of 3M glass microspheres takes the materials into injection moulding after previously being used for years in applications such as sheet-moulded composites and plastisols.