May 17, 2007 – A Japanese firm says that adding carbon nanotubes to antistatic rubber, used to make test benches and transport trays, can improve the strength of the base material and prevent particles from scattering around the cleanroom, notes the Nikkei Business Daily.
Antistatic rubber is typically made by mixing powdered carbon with a melt of resins of polypropylene and other materials, with the final material containing ~20% carbon to help guide electricity through the rubber and prevent static charges from building up. But that much carbon content cuts the polypropylene’s strength in half, and the powdered carbon particles can loosen and scatter around the factory.
To solve this problem, Takiron Co. is mixing carbon nanotubes in with the resin melt (with precisely controlled mixing speed, time, and temperature), where the CNTs’ long thin shapes tangle to create conduits for the electricity. And the CNTs take up a lot less volume than powdered carbon (<5% vs. ~20%), which doesn't lower the strength of the polypropylene, and the CNTs don't scatter around.
Though the new CNT-rubber mixture costs 3-4x as much as conventional products, Takiron is hoping to convince customers that the fewer particles scattered around means an easier time keeping cleanrooms clean, the paper notes. The company also expects to sell the new material to other industries where static discharges are a serious concern, such as chemical factories and gas stations. A commercial version is planned for two or three years.